DO COGNITIVE RESOURCES PLAY A ROLE IN OBJECT FUNCTIONALITY AND
AFFORDANCE EFFECTS WHEN COMPUTING SPATIAL RELATIONS?
Brandi A. Klein
A Dissertation
Submitted to the Graduate College of Bowling Green
State University in partial fulfillment of
the requirements for the degree of
DOCTOR OF PHILOSOPHY
August 2012
Committee:
Dale Klopfer, Advisor
Jane Y. Chang
Graduate Faculty Representative
Mary Hare
Dara Musher-Eizenman
ii
ABSTRACT
Dale Klopfer, Advisor
Participants viewed an object with two functi onal sides (e.g., toothbrush: bristles interact
with other objects such as toothpaste; handle allows for interaction between participant and
object). The reference object (e.g., toothbrush) was presented with one located object (e.g.,
toothpaste) at six different locations, and participants completed a sentence-picture verification
task (e.g., responding yes/no to “the toothpaste is above the toothbrush”). Previous research by
Carlson et al. (2006), suggested facilitation for located objects on the side that allows for
interaction between two objects, which they theorized was moderated by attention. Tucker and
Ellis (1998), using a bimanual response, found facil itation for th e handle side of th e object. The
current study used a vocal response, a bimanual response, and a spatial distractor task to
determine the role of cognitive resources in these facilitation effects; however, little-to-no
evidence of each facilitation effect was found.
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TABLE OF CONTENTS
Page
CHAPTER 1: INTRODUCTION ..........................................................................................
1
Attention and Functionality .......................................................................................
4
Spatial Attention and Working Memory....................................................................
8
Affordances and Functionality ...................................................................................
12
Affordances and Cognitive Load ...............................................................................
17
The Current Research ................................................................................................
19
CHAPTER 2: STUDY 1 ........................................................................................................
20
Method
...........................................................................................................
Participants
22
....................................................................................................
22
......................................................................................................
22
Stimuli
............................................................................................................
22
Design
............................................................................................................
23
......................................................................................................
24
Results
............................................................................................................
24
Discussion
............................................................................................................
26
CHAPTER 3: STUDY 2 ........................................................................................................
28
Apparatus
Procedure
Method
............................................................................................................
Participants
.....................................................................................................
Apparatus, Stimuli, and Design
30
30
.....................................................................
30
.......................................................................................................
30
Results ……... ............................................................................................................
30
Procedure
iv
Discussion
............................................................................................................
33
CHAPTER 4: STUDY 3 ........................................................................................................
35
Method
............................................................................................................
Participants
37
....................................................................................................
37
......................................................................................................
38
Stimuli
............................................................................................................
38
Design
...........................................................................................................
38
......................................................................................................
38
...........................................................................................................
39
............................................................................................................
49
CHAPTER 5: GENERAL DISCUSSION ...........................................................................
52
REFERENCES
............................................................................................................
57
APPENDIX A: FIGURES ....................................................................................................
60
APPENDIX B: HSRB APPROVAL ...................................................................................
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Apparatus
Procedure
Results
Discussion
v
LIST OF FIGURES
Figure
1
Page
Proportion of spatial preposition use in a production task in which participants
were shown images of reference objects with located objects at various positions
surrounding the reference object. Participants were asked to describe the relation
of the located object to the reference object. Each cell corresponds to a different
location of the located object. Figure 1a corresponds to the use of vertically
oriented terms such as above, below, and over. Figure 1b corresponds to the use
of horizontally oriented terms such as left, right, and beside. Darker shaded cells
imply a greater use of these terms (Hayward and Tarr, 1995)...................................
2
60
The attentional vector-sum (AVS) model with modifications for predicting spatial
relations of functional objects in panel f (Carlson, Regier, Lopez, and Corrigan,
2006)……...... . ..........................................................................................................
3
A simulation of the influences of functionality and geometry on an object with a
functional side (a toothbrush) (Carlson, Regier, Lopez, and Corrigan, 2006)...........
4
63
Reaction times (ms) in Study 1, using the toothbrush, for the interaction between
object orientation and spatial relation. .......................................................................
6
62
The reference object and 10 different located object locations used by Carlson,
Regier, Lopez, and Corrigan (2006). .........................................................................
5
61
64
This is an example of a dot memory grid. Participants’ task is to memorize the
location of the dots and remember them at the end of a trial by selecting a grid
from a multiple choice test item.................................................................................
64
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7
Reaction times (ms) in Study 3, using the toothbrush, for the interaction between
spatial relation and hand of response. ........................................................................
8
Reaction times (ms) in Study 3, using the toothbrush, for the interaction between
spatial relation, cognitive load, and hand of response (load condition). ...................
9
68
Reaction times (ms) in Study 3, using the toothbrush, for the interaction between
load, orientation, placement, and hand of response (no load condition) ...................
14
67
Reaction times (ms) in Study 3, using the toothbrush, for the interaction between
load, orientation, placement, and hand of response (load condition) ........................
13
67
Reaction times (ms) in Study 3, using the toothbrush, for the interaction between
spatial relation, object orientation, and hand of response (below condition) ............
12
66
Reaction times (ms) in Study 3, using the toothbrush, for the interaction between
spatial relation, object orientation, and hand of response (above condition). ...........
11
66
Reaction times (ms) in Study 3, using the toothbrush, for the interaction between
spatial relation, cognitive load, and hand of response (no load condition). ..............
10
65
69
Mean reaction times (ms) for the no load condition with left hand responses as a
function of spatial relation and located object placement of the toothbrush,
oriented to the left (Triad A)......................................................................................
15
70
Mean reaction times (ms) for the no load condition with right hand responses as a
function of spatial relation and located object placement of the toothbrush,
oriented to the left (Triad B). .....................................................................................
16
70
Means reaction times (ms) for the marginally significant effect of placement for
the load/no load comparison (as a function of spatial relation) in Triad A (left
orientation, left hand response)..................................................................................
71
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17
Mean reaction times (ms) for the interaction between load and spatial relation, for
left hand responses to the toothbrush, oriented to the left (Triad A). ........................
18
Mean reaction times (ms) for the interaction between load and placement, for left
hand responses to the toothbrush, oriented to the left (Triad A). ..............................
19
72
Mean reaction times (ms) for the interaction between load and placement, for
right hand responses to the toothbrush, oriented to the left. ......................................
20
71
72
Means reaction times (ms) for the significant effect of placement for the load/no
load comparison in Triad D, as a function of spatial relation (right orientation,
right hand response)...................................................................................................
73
1
CHAPTER 1: INTRODUCTION
Interpreting spatial relations among objects and how those objects relate to each other has
been a topic of interest in many studies. Traditionally, when people try to determine if a located
object is above or below a reference object, the principles of geometry are used. For example, if a
participant is given an elongated rectangle and asked to draw a dot above the rectangle, the
participant will not draw the dot above the left or right corners—even though those locations are
still above the rectangle. Instead, they place the dot above the direct center of the rectangle
(Logan & Sadler, 1996; Hayward & Tarr, 1995, see Figure 1). However, if the reference object is
changed from a rectangle to a toothbrush, and the located object is changed from a dot to a tube
of toothpaste, something very different happens. When asked to place the toothpaste above the
toothbrush, participants place it all the way down on the end—directly above the bristles of the
toothbrush (Carlson-Radvansky, Covey, & Lattanzi, 1999). This indicates that participants are
interpreting above based on the reference object’s function and the interaction between the
reference and located objects. There is some evidence that attention is used to moderate this
effect (see Carlson, Regier, Lopez, & Corrigan, 2006). Other studies have been done which have
found that it’s not only the interaction between objects that matters, but also the potential
interaction between the objects and the observer. Tucker and Ellis (1998) found that, when
presented with an object with a handle on the right side, the observer’s right hand was primed for
response, even if the observer had no intention to use the object.
The current study used pictures of objects that have two functional sides localized on
different parts of the object in an attempt to learn more about how people use attention and other
cognitive resources when viewing an object, and how these resources relate to the computation
of spatial relations. The two functional sides of the objects differ in that one side demonstrates a
2
functional use between the participant and the object and the other side demonstrates a functional
use between two objects presented on the screen. For the purposes of the present study, one
functional side of an object is the side that a person can grasp or handle, and the second
functional side of an object is the side that interacts with other objects in the environment. For
example, a picture of a toothbrush has a handle (the side that a participant could grasp if it were a
real object) and bristles (the side that could interact with a tube of toothpaste). These objects
were used in the study to combine the idea of facilitation of responding for graspable sides of
objects with the notion that, when discerning spatial relations, attention is drawn to the side of
the object that interacts with other objects in the environment [see Carlson, Regier, Lopez, and
Corrigan (2006) below].
For three separate studies, participants saw a reference object with both types of
functional sides (e.g., a handle and bristles), and there was a related located object in one of six
positions surrounding the reference object. For example, a tube of toothpaste is an object that is
related to a toothbrush because the bristles of the toothbrush typically interact with toothpaste.
For the first study, participants were asked to complete a sentence-picture verification task to
determine if a sentence that describes the spatial location of the located object in relation to the
reference object (above or below) is correct. They made a vocal response into a microphone. For
the second study, participants performed the same sentence-picture completion task as in Study
1; however, they used a bimanual response (instead of a vocal response) to check for facilitation
of response when the hand of response matches the side of the handle on the object. In the third
study, the same procedure was used as Study 2; however, a distractor task was used in the form
of a dot memory task. At the start of each trial, participants were presented with a grid of dots
and asked to remember the positions of those dots. They then completed the same sentence-
3
picture completion task as in Study 2, after which they were asked to select the correct grid of
dots from a multiple choice test. The distractor task was added to assess the effects of cognitive
load on both the facilitation of responding for functional sides of objects (e.g., the bristles of a
toothbrush) and the facilitation of responding when the hand of response matches the graspable
side of an object.
These three studies were conducted in an attempt to study the role of cognitive resources
in the previously found affordance effects and functionality effects when computing spatial
relations. Because the sentence-picture completion task used by Carlson et al. (2006) (and all
three of the current studies) requires the computation of spatial relations, it was believed that the
addition of a spatial distractor task could illuminate whether spatial attention plays a role in the
facilitation of responding for ideal locations for functional interaction between a reference and
located object and the facilitation of responding when the hand of response matches the
graspable side of a presented object. Study 1 was intended to replicate the functionality effects of
Carlson et al. (2006) using different objects and the computation of both spatial locations above
and below. Study 2 then used the same task with a bimanual response in order to assess whether
Tucker and Ellis’s (1998) facilitation effects for graspable side of objects would occur using the
task of Carlson et al. (2006), which required the computation of spatial relations. Study 3 was
designed to add a spatial distractor task on top of the already established task from Study 2. The
hypothesis was that if spatial attention was recruited for the functionality and graspability effects
when computing spatial relations, then these effects should disappear under cognitively taxing
conditions. This would provide some evidence that spatial cognitive resources were recruited
when participants were processing the functionality of the object and how they could interact
4
with that object—evidence that would potentially affect the way spatial relations are computed
when using a functional object or an object with a graspable handle.
Attention and Functionality
As mentioned above, several studies have theorized that attention is the factor that is
responsible for the computation of spatial relations, and that attention can be focused on objects
differentially depending on the function of the object. One such study presented a computational
model developed by Regier and Carlson (2001), the Attentional Vector-Sum (AVS) Model,
which predicts acceptability judgments for spatial terms (such as above and below). The model
does this by evaluating a trajector (located object) relative to a landmark (reference object), and
indicating how well the particular spatial term (e.g. above) describes the relation between the two
objects. As suggested by the name of the model, the critical components are attention and the
sum of the attentional vector components. The model computes acceptability in this manner: first
an attentional beam is focused on the landmark at the point where it is vertically aligned with the
trajector (see Figure 2a). The most attention is directed to the parts of the landmark that are near
the center of the beam, whereas the more distant parts of the landmark receive less attention. A
vector is rooted at each point on the landmark, pointing toward the trajector (see Figure 2b).
These vectors are weighted by the amount of attention at their base (see Figure 2c), and the
model computes the vector-sum over all of these vectors (see Figure 2d) before comparing it
with the vertical axis (for the positions above and below; see Figure 2e).
According to the AVS model, the farther a trajector is from the landmark, the wider the
attentional beam will be, and likewise, the closer a trajector is to the landmark, the narrower the
attentional beam will be. Attention is focused most strongly at the center of the beam and drops
off with distance from the center. Because of this, closer objects will fall within the focused
5
attentional beam, and they will likely be strongly influenced by attention and less strongly
influenced by the actual geometry of the landmark (see Figure 2f).
To show that there are indeed functional influences on the comprehension of spatial
relations, and to demonstrate that geometry is not sufficient to describe spatial relations, CarlsonRadvansky, Covey, and Lattanzi (1999) performed two separate tasks. For the first task, a picture
of a reference object (e.g., a toothbrush) was taped onto the wall. Participants were given a
picture of a located object (e.g., a tube of toothpaste) and asked to place the toothpaste above the
toothbrush. They found that there was a bias to place the toothpaste above the bristles of the
toothbrush as opposed to above the geometric center of the toothbrush. Moreover, this bias was
much stronger when the reference and located objects were related (e.g., toothbrush and
toothpaste) than when the reference and located objects were unrelated (e.g., toothbrush and
mustard bottle). A simulation of these predicted influences of functionality and geometry can be
found in Figure 3. In a second task, they presented participants with a picture of a piggy bank.
There were three different groups: one group received a picture where the slot of the piggy bank
was towards the front, one group received a picture where the slot was towards the back, and one
group received a picture where the slot was in the middle. Participants were shown images of
coins at many different locations around the piggy bank and were asked to rate the acceptability
of a sentence (e.g., the coin is above the piggy bank) for each of these different locations. Results
indicated that the acceptability ratings shifted as the piggy bank slot shifted. This demonstrated
that the perceived function of the piggy bank and the perceived interaction between the coins and
the piggy bank had a significant effect on how spatial terms were judged.
After the previous study found that the function of an object could indeed influence how
a person computes spatial relations involving that object, Carlson and Kenny (2006) conducted a
6
study to further clarify the relationship between geometry and function. They wanted to know if
toothpaste was primed for a toothbrush simply because they are associated with one another or
because they are positioned in such a way that allowed the two items to interact. For their study,
they used reference objects (e.g., a curling iron), and placed each object in front of the
participants one at a time. They then gave the participants other objects that would serve as
“located” objects (e.g., a wig or a power strip), and the participants were asked to place the
located objects above/below/etc. the reference object. Some of the reference object/located
object pairs were related because they typically interact with each other (e.g., a curling iron and a
wig), and some of the pairings were unrelated because they do not typically interact with each
other (e.g., a coffee cup and a telephone). Their results indicated that when a reference object and
a located object were related, the located object was placed in a location that was best suited for
interaction with the reference object (i.e., the function of the reference object was being taken
into account). When the reference object and the located object were unrelated, the located object
was placed in a location that was described as the best “geometric” location. Carlson and Kenny
(2006) concluded that the advantages seen by the functional stimuli emerge as a result of
reference and located objects being positioned in such a way that they are able to interact with
each other (e.g., a tube of toothpaste being upside down over the bristles of a toothbrush as
opposed to upright). Thus, it is not only an association between two items that moderates
perception of spatial relations; the items must be positioned in such a way that participants can
simulate their interaction.
After this, the study which is the primary focus of the current research, conducted by
Carlson, Regier, Lopez, and Corrigan (2006), examined the extent to which attention is the
unifying force between form and function in spatial language. Both of the studies presented in
7
their paper use sentence-picture verification tasks (Clark & Chase, 1972) in an attempt to
demonstrate the generality of their finding that attention is drawn to the functional side of an
object when computing spatial relations. Carlson et al. (2006) tested their AVS model by first
using a simple rectangle and exogenous cues (cues that draw a person’s attention without their
conscious intention) to draw attention to certain parts of the rectangle, and then by using a
reference object that has a functional side that would allow for interaction with a located object
(e.g., the spout of a watering can interacts with a plant) (see Figure 4). For their first experiment,
they cued a specific portion of a large rectangle and presented located objects at different
locations around the rectangle (see Figure 4a). They found the expected result—that attention
would be drawn to the cued area and therefore, the verification of located objects around that
area would be facilitated. For their second study, they used a functional object (a watering can)
as their reference object, and placed a located object (a plant) in one of ten locations above and
below the reference object (see Figure 4b). The selection of a plant as a located object was
important because they wanted the located object to be something that the reference object (a
watering can) would interact with. They hypothesized that, in accordance with their AVS model,
the located object positions that allowed for the best interaction between watering can and plant
(i.e., the positions beneath the spout) would be the positions that were facilitated. This is because
they also predicted that participants’ attention would be drawn to the functional side of the
reference object (the spout). Another prediction was that geometry would still matter when
making above/below verification judgments. Thus, the locations in the center and the locations
best suited to interact with the reference object should be facilitated. Once again, they found
what they predicted—the plants that were positioned in the center and beneath the spout were
verified more quickly than the plants that were beneath the handle. The current study used the
8
same task as Carlson et al. (2006), modified with different objects, different response modalities,
and the addition of a distractor task to both further test the theory that attention moderates the
interpretation of spatial relations among functional objects, and to determine whether different
results would be obtained when two hands are involved, much like the results of Tucker and Ellis
(1998).
Spatial Attention and Working Memory
One question that arises when considering the interaction between visual perception and
cognition is “what is the role of spatial attention?” In a series of studies, Logan (1994) tested his
theory that the apprehension of spatial relations requires spatial attention. Specifically, any time
a spatial relation such as above, below, left, or right is computed, Logan would argue that
focused spatial attention is being used. Logan (1994) used verification tasks in his experiments
because these tasks require a person to locate two objects and make a decision about the spatial
relation between them. He incorporated these verification tasks with visual search tasks.
For example, in one of his studies, participants were presented with a sentence (e.g., “Is
there a dash above a plus?”) and then a picture display filled with several pairs of dashes and
pluses. A target pair in this case would be a dash above a plus, and the rest of the display would
be filled with distractors, which would be dashes below pluses. The participants’ task was to
determine whether a target pair that matched the sentence was present. Because of this, the
participants had to compute spatial relations between the dashes and pluses in order to complete
the task. Logan (1994) reasoned that if spatial attention was required to compute spatial relations,
this task should be difficult because participants would have to compute the relations between
each of the items in the display until a target pair was found. However, if spatial attention was
not required, and the target pair could be found using pre-attentive processes, then the task
9
should not be difficult, and participants should be able to respond quickly because of “pop-out”
effects. His results were consistent with the theory that spatial attention was used to complete the
visual search.
In another of Logan’s (1994) studies, he specifically manipulated the direction of
participants’ attention. In a visual display much like in the study previously described, one dashplus pairing as colored differently from the others, thereby giving it a pop-out effect and drawing
participants’ attention to that location. In certain instances, this colored pairing was the target
pair, and in other instances, it was a distractor pair. Logan (1994) hypothesized that performance
should be good when attention is directed to the target position and bad when attention was
directed away from the target position (to a distractor). This is exactly what he found. Spatial
relations among the pairs were easier to compute when participants’ attention was drawn to the
target as opposed to when participants’ attention was drawn away from the target. The results of
all of Logan’s (1994) studies are consistent with the theory that spatial attention is required to
compute spatial relations.
Logan (1995) then posited a theory of how visual spatial attention is used to direct
attention from one object to another. He stated that directing attention from one object to another
(as in the current study) is different from directing attention to a single object. He then argued
that this focused visual spatial attention was the result of top-down processing and the use of
reference frames—a reference frame that defines direction in perceptual space and a reference
frame that defines the direction from one object to another (Logan, 1995). An observer must first
locate the desired cue, then locate a target with respect to the cue, and lastly, perform whatever
task is required with the target. Logan theorized that observers have voluntary control over these
processes and can adjust their reference frames as necessary. This reference frame selection
10
requires attention because, in theory, an infinite number of reference frames could be used for
any given visual display. The reference frame that a person actually selects and uses has to be
chosen from many different options, and Logan (1994) argues that attention is how a person
makes this selection.
The notion that attention and other cognitive resources related to executive functioning
play a strong role in visual spatial information was also examined in a study by Logie, Zucco,
and Baddeley (1990). They wanted to examine the nature of storage of visuo-spatial information
in short-term memory. Baddeley and his colleagues had previously proposed the notion of
working memory, which involves both the tasks associated with short-term storage and the
processing of information in that storage (Baddeley & Hitch, 1974, as cited in Logie, Zucco, &
Baddeley, 1990). Working memory involved executive functioning (e.g., reasoning, decisionmaking), whereas short-term memory previously had not. Importantly, attention was required in
order to hold information in working memory and to use the information in working memory.
They proposed two working memory subsystems: the articulatory loop, which processed verbal
material, and the visuo-spatial sketchpad, which processed visuo-spatial information. Logie,
Zucco, and Baddeley (1990) devised a study to determine whether there was a specialized visuospatial system in working memory, or whether all verbal and visuo-spatial tasks drew from the
same pool of cognitive resources (such as attention). In two studies, they had their participants
perform either a visuo-spatial memory task or a verbal memory task, and paired each of these
tasks with a secondary distractor task which was either related to arithmetic (Study 1), verbal
memory (Study 2) or visuo-spatial imagery (Study 1 and Study 2). They found that using a
visuo-spatial secondary task interfered with performance on a visuo-spatial primary task
significantly more than it interfered with performance on a verbal task. The opposite was also
11
true—using a secondary task related to arithmetic or verbal memory interfered significantly more
with performance on a verbal task than it interfered with performance on a visuo-spatial task.
These results supported their hypothesized two separate mechanisms in working memory: verbal
(articulatory loop) and spatial (visuo-spatial sketchpad). They argue that while a “supervisory”
general pool of resources may be used, it functions to allocate its resources to separate pools of
resources for verbal and visuo-spatial tasks (Logie, Zucco, & Baddeley, 1990).
A later study conducted by Cocchini, Logie, Sala, MacPherson, and Baddeley (2002)
replicated and extended the results of Logie, Zucco, and Baddeley (1990). They found that the
addition of perceptuomotor tracking (tracking a dot in a screen with a light-sensitive stylus) as a
secondary task showed no disruption in either verbal or visuo-spatial primary tasks. They also
confirmed that there was little-to-no disruption of a visuo-spatial task while performing a verbal
secondary task, and little-to-no disruption of a verbal task while performing a visuo-spatial
secondary task. Again, the verbal and visuo-spatial tasks had little-to-no mutual interference.
They also extended the previous study by using articulatory suppression (repeating a word over
and over again) as a secondary distractor. As expected, the articulatory suppression interfered
significantly more with the verbal primary task than with the visuo-spatial primary task
(Cocchini, Logie, Sala, MacPherson, & Baddeley, 2002). Their results were once again
consistent with the theory of two separate pools of cognitive resources for verbal working
memory and visuo-spatial working memory.
Furthering research in the visuo-spatial working memory domain, Miyake, Friedman,
Rettinger, Shah, and Hegarty (2001) conducted a study in order to determine whether complex
working memory visuo-spatial tasks differed from simpler short-term memory visuo-spatial tasks
with respect to executive functioning. Previous research in the verbal domain had found
12
consistent evidence of a difference in the amount of recruited executive functioning resources
between verbal short-term memory and verbal working memory tasks. For example,
performance on working memory tasks is a better predictor of reading comprehension (see
Daneman & Merikle, 1996) and general fluid intelligence (see Engle, Tuholski, Laughlin, &
Conway, 1999) than performance on short-term memory tasks (Miyake, Friedman, Rettinger,
Shah, & Hegary, 2001). The common assumption that there was a difference in visuo-spatial
working memory tasks and visuo-spatial short-term memory tasks was based on evidence from
the verbal domain and had not been explicitly tested within the visuo-spatial domain. Through
administering a series of tests of executive functioning, visuo-spatial working memory, and
visuo-spatial short-term memory, Miyake et al. (2001) discovered that visuo-spatial working
memory tasks and visuo-spatial short-term memory tasks were equally related to executive
functioning. The executive functioning tests were almost equally correlated with both the visuospatial working memory tests and the visuo-spatial short-term memory tests. These results are
consistent with the theory that, while the phonological loop (verbal working memory system)
and the visuo-spatial sketchpad (visuo-spatial working memory system) are separate, the visuospatial sketchpad may be more closely tied to the central executive. Even short-term visuospatial memory tasks seem to need to recruit resources from the central executive (Miyake et al.,
2001). This study is important for the current research, which used a visuo-spatial short-term
memory task as a distractor task in an attempt to tax the central executive.
Affordances and Functionality
The attention research previously described is important to all three studies involved in
the current research; however, Study 2 also incorporated the previously discussed effect of the
handle of an object priming the hand of response if they are on the same side. This concept of the
13
handle of an object granting the observer a facilitatory benefit is known as an affordance, which
was first put forth by James Gibson in 1977. According to Gibson, affordances of the
environment refer to what the environment offers or provides for an animal (or human).
Affordances “relate the utility of things, events, and places to the needs of animals and their
actions in fulfilling them” (Gibson, 1982, 60). Gibson maintained, however, that the affordances
granted to an observer were specified in the stimulus information—that the affordance was a
property of the stimulus itself, as related to the observer (Gibson, 1979). For example, in order
for something to have the affordance of graspability, it must be of a certain size, weight, and
rigidity, and the observer must possess hands of a sufficient size to grasp it (Gibson, 1982). The
surface of the ground people are walking on affords physical support. In the case of affordances
of objects, a perception-action loop is activated that is independent of knowledge or goals
(Gibson, 1979). The affordance can be driven purely by the information contained in the optic
array. For example, an image of a frying pan can afford a reaching and grasping movement just
because a participant perceives the graspable portion of the pan called a handle.
Tucker and Ellis (1998) conducted studies on affordances of objects that have a perceived
functional use between the participant and the object (objects that have graspable handles).
Participants were shown photographs of objects such as a frying pan, and their task was to decide
whether the object was upright or inverted. They hypothesized that the mere perception of a
photograph of an object with a handle on the right side would prime a reaching and grasping
motor movement with the participants’ right hands. Thus, they anticipated that when the handle
was on the right side of an object, the participants would be quicker to respond with their right
hand, and when the handle was on the left side of an object, the participants would be quicker to
respond with their left hand. This is exactly what they found. Over a range of common objects
14
with handles, the side of the handle primed the hand of response. Tucker and Ellis (1998)
interpreted this affordance effect as evidence that visual objects can potentiate actions (such as
reaching and grasping), even when the participant has no intention to act on them. They explain
that this could possibly be because when the actions that the object affords are potentiated, this
results in the automatic activation of motor responses. In other words, the “intention to act” upon
an object is not necessary. Interestingly for the purposes of the present study, the affordance
effect went away when Tucker and Ellis (1998) asked participants to respond with their index
and middle finger of one hand (a unimanual response) rather than with the index fingers of the
left and right hands (a bimanual response). This provides further evidence for the automatic
activation of reaching and grasping movements for each hand.
In a subsequent study, Tucker and Ellis (2004) examined the extent to which different
objects afford different forms of grasping. Participants made “natural/manufactured” judgments
of objects on the computer screen (e.g., a grape is a natural object and a key is a manufactured
object). These objects were also either small enough to have to make “precision” grasps (e.g., a
nut, a key, etc.) or large enough to make “power” grasps (e.g., a squash, a bottle, etc.); although
this dimension was irrelevant to the participants’ task of making a natural/manufactured
judgment. Participants made their judgments by using a special grasping device. Participants
grasped the device by encircling their middle, ring, and little fingers around the bottom of a
cylinder and wrapping their thumb and index finger around the top of the cylinder. Each of these
two areas of the cylinder possessed a trigger. Participants were instructed to make their
natural/manufactured judgments by squeezing either the trigger of their middle, ring, little
fingers (which corresponds to a power grasp) or the trigger of their thumb and index finger
(which corresponds to a precision grasp). These responses were counterbalanced across
15
participants. This task was used in three different studies to determine the strength of affordance
effects. First, through the use of backward masking, affordance effects were obtained even when
the stimulus was no longer present on the screen. Specifically, responses to small objects were
made faster with the precision grasp than with the power grasp, and the opposite was true for the
large objects. Second, using both degraded contrast and occlusion to reduce the visibility of the
objects, similar patterns of affordances were still obtained. Third, object names (words) were
used in addition to object images. Participants saw a mixture of names and objects, and the
results indicated that there was no significant difference between the affordances of words and
images. These studies together suggest that a representation of an object is enough to grant
affordances, and that visual perception of the object is not actually necessary (Tucker & Ellis,
2004).
Masson, Bub, and Breuer (2010) performed a very interesting study which combined
functionality and graspability effects and is important for the rationale of the current research.
They showed participants pictures of stimuli with a manual side which would be graspable to the
participant if it were a real object (e.g., a handle, such as on a beer mug). They showed the
images not only at their proper orientations, but also rotated 90 degrees. Their reason for doing
this was to determine if it was the mere physical orientation of the stimulus that primed the
responding of the hand on the same side as the handle, or if some higher level processing
contributed. If higher-level processing does occur (such as computing the function of the object),
one would expect that not only would the object afford the responses of the proper hand when it
is at its upright orientation, but also when it is rotated 90 degrees—but rotated 90 degrees in such
a way that it would be possible to rotate with that same proper hand. For example if a person is
holding a beer mug in his/her right hand, with the handle on the right side, and an attempt is
16
made to pour the beer, the natural way to make the 90 degree rotation is to the left (counterclockwise). An attempt to tip the mug 90 degrees in the opposite direction would leave the
person’s arm at an awkward angle. Participants were shown an image of a beer mug rotated at
either 0 degrees or 90 degrees. After this, they were shown an image of a hand making either a
vertical or a horizontal grasp. This hand image was their cue for the specific reach and grasp
motion they were supposed to make. In analyzing the data, Masson et al. (2010) wanted to
determine if there was a difference in reaction time between when the image of the beer mug and
the image of the hand were congruent or incongruent. The results indicated that the upright (0
degrees of rotation) congruent objects were primed for the proper reach and grasp motion
compared to the incongruent objects. They also found that the 90 degree rotated objects were
also primed—but to a lesser degree, and only if they were rotated in the direction that was proper
for the object’s use. If they were rotated in the direction that was inappropriate for object use,
there was no priming effect. This study is important because it incorporates the functionality of
an object with the affordances granted by an object.
There have been many studies on affordances and the tasks that lead to them. For the
purposes of the present study, an affordance is granted when the perception of an object lends a
facilitatory benefit to a participant’s response time during a task. Information contained in the
viewed object automatically lends these affordances to participants, even without an intention to
use that object. As can be seen in the evidence provided by Masson, Bub, and Breuer (2010) and
Tucker and Ellis (1998), affordances that prime reach-and-grasp motions can be found when
viewing common objects that have handles. Unique to Masson, Bub, and Breuer (2010),
however, is the notion that object response times are primed at orientations that are appropriate
for their functional use but not at orientations that are not appropriate for their functional use.
17
Affordances and Cognitive Load
As previously stated, Gibson (1979) declared that objects can provide affordances for
their use based solely on the physical characteristics of the object. In his view, the object does
not need to be categorized and its function does not need to be known in order to grant
affordances to an observer. A person does not even need to know what an object is—just that, for
example, it is cylindrical and small in diameter and can therefore afford a grasping response. So
according to Gibson (1979), the affordance is contained specifically in the visual information of
the object, without an appeal to higher-level cognition.
The previously discussed research of Tucker and Ellis (1998) takes this notion and
expands upon it. They believe that objects can automatically activate potential actions (motor
responses) based solely on a person’s visual perception of that object; however, they
acknowledge that the actions that are directed towards an object are tied to the function of the
object. A person’s experience with an object determines which motor responses are appropriate
to use for that object. For example, the hand-shape for reaching out and grasping a pen is not the
same as the hand-shape for writing with a pen. Tucker and Ellis (1998) believe that the
information necessary to grant affordances is present before a person actually decides to use an
object; that is, affordances can be granted even in the absence of an intention to act upon the
object. For example, if a person reaches out and grasps an object, Tucker and Ellis would argue
that the information for the required hand-shape for grasping is present at the time of the
perception of the object (i.e., hand-shape information is not suddenly created the moment the
person makes the decision to reach out and grasp the object). So while Tucker and Ellis (1998)
acknowledge that some cognition comes into play (i.e., knowing the function of an object
determines the actions that can be applied to that object), they also demonstrate that the
18
perception of an object is enough to grant affordances, even without planning on actually using
the object.
Further examining the interaction of cognition and affordances, Creem and Proffit (2001)
argue that while a person might be able to reach out and grasp an object without an appeal to
cognition, making a reach and grasp motion that is appropriate for the use of the specific object
does require cognition. For example, they explain that if a person were to reach out and grasp a
toothbrush, he/she would grasp the handle and his/her hand would be positioned in such a way as
to allow for appropriate use of the toothbrush; however, if a person’s cognitive processing is
taxed, he/she will pick up the toothbrush by the bristles as much as by the handle. Because of
this, they argue that cognition and action are not always separate systems—they can interact with
each other.
The assertions of Creem and Proffit (2001) are based on an interesting series of studies
they conducted using reach and grasp movements and a distractor task. Through their studies,
they determined that anytime semantic processing was necessary to select the appropriate action
towards an object, there was an interaction between the cognitive and action systems of the
mind. The task of their participants was to make appropriate grasp movements (i.e., not just to
pick up a spatula, but to pick it up in the manner that would make it easiest to use). Their results
indicated that the grasping task proved too difficult when it was paired with a semantic dualtask—errors increased drastically. However, when the grasping task was paired with a spatial
dual-task, there was no significant performance decrease. They concluded that the semantic
system was necessary for appropriate grasping of objects. When the semantic system was
overtaxed, the participants were still able to grasp the objects, but not in a manner appropriate for
use. This implies that cognitive resources such as semantic knowledge are consumed when
19
affordances are granted for the proper use of an object. Another study in this series by Creem and
Proffitt (2001) used a visuomotor task (which had no semantic component) instead of a reach
and grasp task. For this task, they found the reverse effects of their previous study—visuomotor
performance was impaired by a spatial dual-task but not by a semantic dual-task. This implies
that cognitive resources are also consumed while performing spatial tasks.
While Creem and Proffitt (2001) and Tucker and Ellis (1998) do not seem to argue with
Gibson’s (1979) assertion that physical properties of the object can grant affordances without an
appeal to higher cognition, they do make some modifications to his original assertion. Tucker
and Ellis (1998) believe that the specific motor responses that are activated by the perception of
an object can change depending on the function of an object; therefore, the function of an object
is processed. Creem and Proffitt (2001) demonstrated that while an object can afford an action
based solely on its physical characteristics, if the object has a function and is to be used in a
manner that is appropriate for its function, cognitive resources are consumed.
The Current Research
The current research consisted of three different studies. The purpose of these studies
was: 1) to replicate the results of Carlson, Regier, Lopez, and Corrigan (2006) requiring the
computation of spatial relations for both above and below using different objects, different
orientations, and a different response modality, 2) to combine the Carlson et al. (2006) task with
the response modality and theory behind Tucker and Ellis (1998) to examine affordances using a
sentence-picture verification task with spatial relations, and 3) to further test the functionality
effects of Carlson, et al. (2006) and the affordances effects of Tucker and Ellis (1998) by using a
distractor task to determine the extent to which cognitive resources such as spatial attention are
recruited during the task of computing spatial relations.
20
CHAPTER 2: STUDY 1
The task of Carlson et al. (2006) demonstrates that the computation of spatial relations is
moderated by the function of the reference object in relation to the located object. This notion
that the function of an object is taken into account leads to the issue of how attention is
distributed across an object with functional parts when participants have to make spatial relation
judgments involving those objects. If the reference and located objects are unrelated, then
geometry determines the appropriateness of a given spatial relation. On the other hand, if the
reference and located objects are related, then both function and geometry play a role in the
appropriateness of spatial relations because attention is drawn to the functional side of the
reference object that will interact with the located object (e.g., the bristles of a toothbrush).
Carlson et al. (2006) only used one reference object/located object pair (a watering can
and a plant), which only measured one spatial functional spatial location (below). The current
study expanded upon this research by using two different reference object/located object pairings
(toothbrush/toothpaste and hammer/nail), one of which examines the spatial location above
(toothbrush/toothpaste; the ideal interaction takes place above the bristles of the toothbrush), and
the other examines the spatial location below (hammer/nail; the ideal interaction takes place
below the head of the hammer). In addition, a vocal response was used rather than the unimanual
response used by Carlson et al. (2006), to make sure the functionality effect still occurs without
adding in a response translation to the hands. Also, the images used in the present study were
larger than the images used in the Carlson et al. (2006) study, in order to approximate the reallife size of the objects if they were to be perceived and interacted with in the real world. Lastly,
only six located object positions (three locations above and three locations below the reference
object) were used, as opposed to the 10 located object positions used by Carlson et al. (2006).
21
These changes were made to the original Carlson et al. (2006) task after a previous
attempt to replicate her findings using her task and procedure yielded mixed and inconsistent
results. For example, the ideal location for interaction between a watering can and a plant was
facilitated when the watering can was oriented in one direction, but not when the watering can
was oriented in the other direction (Klein, 2011). Also, the far left and far right located object
positions (out of 5 positions above and 5 positions below the reference object) were extremely
different from the near left and near right positions; because of this, far too much variance was
entered into the data (Klein, 2011). Indeed, Carlson et al. (2006) ended up averaging over the far
left/near left and far right/near right locations in their original research as well. One potential
reason why stronger function effects were not found could have been due to the use of a
bimanual response. When using a bimanual response to an object such as a watering can, there
could have been competing effects of functionality (i.e., the spout interacting with a plant) and
affordances (i.e., the participants hand of response matching the side of the handle). Because of
this, the current study used a vocal response. It was believed that the suggested changes (such as
reducing the located object positions to three above and three below the reference object) could
improve upon the methodology if the functionality effect was reliable.
Participants were given instructions for completing a sentence/picture verification task.
They were told that they were going to see a sentence presented on the screen (e.g., the
toothpaste is above/below the toothbrush), after which a picture display would be presented
containing both the reference and located objects. The reference object and located object were
two items that could interact with each other (toothbrush/toothpaste or hammer/nail). The
participants’ task was to verify whether the sentence was an accurate description of the picture
by making a yes or no response into a microphone. The located object (e.g., a nail) was presented
22
in one of six locations (three above and three below) around the reference object (e.g., a
hammer). Based on previous research, the prediction was that the located objects that follow the
rules of geometry (center of the reference object) and functionality between reference and
located objects (prime locations for interaction between reference and located objects) would be
the locations with the most facilitation. For example, when the head of the hammer is on the
right and the nail is below the right side of the hammer, that location should be facilitated as
compared to the left location; however, the geometric center would probably still be the fastest,
but not significantly faster than the facilitated left location. This would show the functionality
effect. No functionality effects should be seen for the locations above the hammer, as those
locations are not ideal for interaction between a hammer and a nail.
Method
Participants
The participants were 41 psychology student volunteers (37 females, 4 males) who were
tested individually in one 45 minute session and received partial course credit as compensation.
All participants had normal or corrected-to-normal vision.
Apparatus
The experiment was run using E-Prime (Schneider, Eschman, & Zuccolotto, 2002)
software that controlled stimulus presentation and collected data on a Dell Dimension 8250
computer with a 24 inch color monitor. Presentation of the located object started a millisecond
timer, and a vocal response into a microphone stopped the timer.
Stimuli
The stimuli used for the sentence-picture verification task were both sentences and
picture displays. There were four different sentences: the toothpaste is above/below the
23
toothbrush, and the nail is above/below the hammer. These sentences were presented in Arial,
black, 36-pt font, in the center of a white screen. The picture stimuli were two reference objects
(a toothbrush and a hammer) and two located objects (a tube of toothpaste and a nail). One
reference object was always present in the center of the screen, and one located object appeared
in any of six locations, three above and three below the reference object. The reference objects
were approximately 31.00 cm x 4.00 cm for the toothbrush and 38.00 cm x 10.00 cm for the
hammer, and the located objects were approximately 10.00 cm x 2.00 cm for the toothpaste and
6.00 cm x 1.00 cm for the nail. For the six locations of the located objects, there were three
locations evenly spaced above the reference object and three locations evenly spaced below the
reference object. There was approximately 8.00 cm of space between the centers of each located
object horizontally and approximately 8.00 cm of space vertically.
Design
This experiment consisted of a 2 object (toothbrush vs. hammer) X 2 orientation (left vs.
right) X 2 spatial relation (above vs. below) X 3 locations per spatial relation (left, center, right)
within-subjects design. There were 16 trials in each condition for a total of 384 experimental
trials. All conditions varied randomly throughout the experiment.
Procedure
Participants were given instructions for completing a sentence/picture verification task.
They were told that they were going to see a sentence presented on the screen (e.g., “the
toothpaste is above the toothbrush”), after which a picture display would be presented. Their task
was to verify whether the sentence was an accurate description of the picture by making a yes or
no response into their microphone. Participants were instructed to make their response as quickly
but as accurately as possible. The experiment began with a set of 12 practice trails that were
24
followed by the 384 experimental trials. Once the participants confirmed that they understood the
task, they initiated the experiment by pressing the space bar. Using the timing of Carlson et al.
(2006), each trial began with a 2000 ms presentation of a sentence to be verified (e.g., “the nail is
below the hammer”), followed by a 500 ms pause, and then the picture display containing the
reference and located object was presented. The located object was presented in one of six
locations (three above and three below) around the reference object. The picture display
remained on the screen until a vocal response was made. After the participant’s response, the
experimenter keyed in whether they responded yes or no. The participant then pressed the space
bar to initiate the next trial. Response times were measured from the onset of the picture display,
and accuracy of the responses was recorded by the software.
Results
Consistent with previous studies, any trial during which a participant made an error (e.g.,
responded yes when the correct response was no) was removed from the data set. Accuracy for
the participants was high, with an average error rate of only 4.57%. In order to remove outliers,
reaction times that were further than 2.5 standard deviations away from each participant’s mean
reaction time were removed from the analysis and replaced with each participant’s mean
response time. This resulted in 3.3% data replacement. Of the remaining data, only correct yes
responses were analyzed (as in Carlson et al., 2006).
The following analyses describe the results of Study 1, which used the sentence-picture
completion task of Carlson et al. (2006) with two different objects (in order to measure both the
above and below spatial relations) and a vocal response. First, the reference object/located object
pairing of the hammer and the nail was used to study the location below (i.e., the ideal placement
of a nail for interaction with a hammer is below the head of the hammer). A 2 orientation (left,
25
right) X 2 spatial relation (above, below) X 3 placement (left, center, right) within-subjects
ANOVA yielded no significant main effect of object orientation, [F(1, 40) = 0.515, p = .477];
however, there was a significant main effect of spatial relation, with above responses (M =
476.27, SD = 86.64) being quicker than below responses (M = 513.22, SD = 85.42), F(1, 40) =
71.99, p < .001, ηp2 = 0.643. There was also a significant main effect of placement, [F(2, 80) =
17.68, p < .001, ηp2 = 0.307], with the center placement (M = 478.76, SD = 87.85) being quicker
than both the left (M = 502.30, SD = 82.46) and right (M = 503.17, SD = 87.78) placements.
Pairwise comparisons indicated that the center placement was significantly quicker than both the
left (p < .001) and right (p < .001) placements. None of the interactions was significant (all p’s >
.27). These results provide evidence that the rules of geometry are used when computing spatial
relations; however, they are inconsistent with the results of Carlson et al. (2006), who used a
unimanual response with a reference/located object pairing of a watering can and a plant, and
found facilitation of responding for the location best suited to interaction between the reference
and located objects.
Another goal of this research was to determine if Carlson et al.’s (2006) functionality
effects would spread to different objects and different functional spatial locations. As Carlson et
al. (2006) used one reference object/located object pairing that examined ideal functional
interaction in the spatial location below, the current study also sought to examine the spatial
location above. The reference object/located object pairing of a toothbrush and toothpaste was
used for the following analyses as the ideal placement of a tube of toothpaste for interaction with
a toothbrush is above the bristles of the toothbrush. Once again, a 2 orientation (left, right) X 2
spatial relation (above, below) X 3 placement (left, center, right) within-subjects ANOVA
yielded no significant main effect of object orientation, [F(1, 40) = 0.875, p = .355]; however,
26
there was again a significant main effect of spatial relation, with above responses (M = 458.26,
SD = 84.35) being quicker than below responses (M = 496.99, SD = 84.79), F(1, 40) = 58.86, p <
.001, ηp2 = 0.595. There was also a significant main effect of placement, [F(2, 80) = 13.31, p <
.001, ηp2 = 0.250], with the center placement (M = 465.93, SD = 86.11) being quicker than both
the left (M = 483.68, SD = 86.57) and right (M = 483.26, SD = 81.05) placements. Pairwise
comparisons indicated that the center placement was significantly quicker than both the left (p <
.001) and right (p < .001) placements. In addition to these main effects, there was also a
marginally significant interaction between orientation and spatial relation, with participants
taking longer to respond to the left orientation than the right orientation in the below position,
F(1, 40) = 3.20, p = .081, ηp2 = .074 (see Figure 5). Like the hammer and nail, the toothbrush and
toothpaste showed evidence for the effects of geometry when computing spatial relations, but
showed no evidence of functionality effects using a vocal response.
The current study used double the number of trials of the original Carlson et al. (2006)
study due to the use of two reference/located object pairings. Because of this, the data were
analyzed to determine if fatigue could have been an issue. However, analyzing only the first half
of the data revealed no difference in patterns of responding compared to using both halves
together. There was still no evidence of Carlson et al.’s (2006) functionality effect. The data
were also analyzed using gender as a variable, as male and female participants could have
potentially had differing levels of experience using hammers and nails. However, there were no
significant gender differences among and of the objects and locations (all p’s > .30).
Discussion
Study 1 used the sentence-picture completion task of Carlson et al. (2006) with different
reference/located object pairings and a vocal response in an attempt to replicate their findings of
27
a functionality effect with different objects and with computing both the above and below spatial
locations. It was predicted that the located objects that follow the rules of geometry (center of the
reference object) and functionality between reference and located objects (prime locations for
interaction between reference and located objects) would be the locations with the most
facilitation. While the located objects above or below the center of the reference object were
consistently found to be responded to the quickest, no evidence for Carlson et al.’s (2006)
functionality effect was found.
Other than the different reference object/located object pairings, there were two
differences between this study and the study of Carlson et al. (2006). One difference was that the
sizes of the objects in the current study were much larger. This was done in order to have the
hammer, nail, toothbrush, and toothpaste approximate their real-world sizes. A second difference
was that a vocal response was used as opposed to Carlson et al.’s (2006) unimanual response.
The vocal response was chosen because a previous study by Klein (2011) failed to replicate
Carlson et al.’s (2006) functionality effect using a bimanual response. It was thought that perhaps
using two hands to respond caused competition between reference/located object functionality
effects and potential affordance effects from the hand of response matching the graspable side of
the reference object. A vocal response would eliminate that concern; however, the functionality
effects were still not found. This could be because functionality effects, given that they depend
on interaction between two objects, might be intricately tied to manual responding. The
perceived objects are functional, and therefore the participants interact with them using their
hands. Perhaps a manual response is necessary to find the effects.
28
CHAPTER 3: STUDY 2
Study 2 recognized that there were actually two functions presented in the Carlson et al.
(2006) task used in the previous study—the functional relationship between the reference and
located objects and the interactive functional relationship between the participant and the
graspable side of an object (i.e., a person cannot brush their teeth unless they first pick up the
toothbrush).
Accordingly, the present study was conducted in order to test whether the Attentional
Vector Sum Model (AVS) still made the correct predictions when using a bimanual response as
opposed to a unimanual response (Carlson et al., 2006) or a vocal response (Study 1). In other
words, this study aimed to determine if Tucker and Ellis’s (1998) finding of affordances for
graspable sides of objects would be found in conjunction with Carlson et al.’s (2006) finding of
priming effects for sides of reference objects that interact with located objects while performing
a task that required the computation of spatial relations. The hypothesis of this study was that the
AVS model predictions would not be correct because when using a bimanual response,
affordances would have an effect (facilitation of responses to the graspable side) in addition to
the effect of attention being drawn to the side of the reference object that would interact with the
located object.
The task of Study 2 was the same as the task from Study 1, except a bimanual response
was used instead of a vocal response. The reference object was an object with two functional
sides (one side had a functional relationship with the located object and the other side had a
functional relationship between the participant and the object; e.g., a toothbrush), and the located
object was an image of something that could interact with that reference object (e.g., toothpaste).
It was the bimanual response that could change the way these located objects were facilitated as
29
compared to Carlson et al. (2006). In situations where the hand of response matches the side of
the reference object that would allow for interaction between the participant and the reference
object (i.e., the handle of the reference object), the prediction was that the responses on that side
of the object would be primed. Even though grasping a handle and pressing a button are two
different responses, the fact that both of those responses are carried out with the same hand
should lead to a facilitation of response. When the hand of response did not match the side of the
handle of the reference object, no priming effects were expected.
These hypothesized effects (i.e., that both functional sides of the reference object can
facilitate response times depending on response compatibility), could provide evidence of
affordances being automatically activated when a person perceives an object that he/she could
interact with, and that some attention may be being recruited by both sides of the reference
object (i.e., not just the side that allows for interaction between reference and located objects).
This finding would have implications for the AVS model (if the model is being used with a
bimanual response) because when computing the vector sum of an object with two functional
sides, it would be necessary to make modifications so that the weightings for both sides matter. It
would also extend the results of Tucker and Ellis (1998) to a sentence-picture completion task
that involves the computation of spatial relations. This finding would not, however, indicate that
the meaning of the spatial relation above or below has changed. The meaning of the spatial
relation would remain the same—participants would just be able to respond faster.
On the other hand, opposing results could be found such that when the hand of response
and the graspable side of the object match, the functional relationship between the reference and
located objects becomes enhanced. In this case, the same effects of Carlson et al. (2006) could be
found, except on a larger scale. If this larger effect were found, it could mean that the location
30
that is usually the best location (the geometric center) may no longer be the most primed
location. If the geometric center were no longer the most primed location, this could potentially
provide evidence of a change in the way the spatial locations above and below are understood.
Method
Participants
The participants of Study 2 were 40 psychology student volunteers (26 females, 14
males) who were tested individually in one 45 minute session and received partial course credit
as compensation. All participants had normal or corrected-to-normal vision.
Apparatus, Stimuli, and Design
The apparatus, stimuli, and design used in Study 2 were identical to Study 1, except the
participants entered their bimanual response into the keyboard rather than making a vocal
response into a microphone.
Procedure
The procedure for Study 2 was the same as the procedure for Study 1, except the
response modality changed. Bimanual responses were made using the x and m keys on a standard
keyboard. The index finger of the left hand was above the x key, and the index finger of the right
hand was above the m key. The assignment of yes and no to the x and m keys was
counterbalanced across participants.
Results
As in Study 1, all errors (e.g., responded yes when the correct response was no) were
removed from the data set. Accuracy for the participants was high once again, with an average
error rate of only 3.50%. In order to remove outliers, reaction times that were further than 2.5
standard deviations away from each participant’s mean reaction time were removed from the
31
analysis and replaced with each participant’s mean response time. This resulted in 3.9% data
replacement. Of the remaining data, only correct yes responses were analyzed (as in Carlson et
al., 2006).
As Study 2 used the same task as Study 1 (but with a bimanual response), the same
analyses used for Study 1 were used for Study 2, except hand of response was added in as a
variable in order to check for the effects of affordances (i.e., facilitation of the hand of response
that matches the graspable side of the object). Again, it was thought that left hand responses
would be facilitated when the handle of an object was on the left side and a left hand response
was being used, and right hand responses would be facilitated when the handle of an object was
on the right side and a right hand response was being used. For example, when the hammer is
oriented to the right (i.e., the head of the hammer is on the right and the handle is on the left),
and the participants are responding with their right hands (i.e., the handle and the hand of
response are incongruent), the locations that should yield the fastest reaction times should be the
locations that allow for geometry and interaction between the reference and located objects (i.e.,
the below locations center and right). However, with the hammer still oriented to the right (i.e.,
the head of the hammer is on the right and the handle is on the left), but the participants now
responding with their left hands (i.e., the handle and the hand of response are congruent), the
locations that should yield the fastest reaction times should be the locations that allow for
geometry, interaction between the reference and located objects, and affordances (i.e., all of the
below locations should be primed, including the left position). When the hammer is oriented to
the left (i.e., the head of the hammer is on the left and the handle is on the right), the predictions
reverse. If the participants are using their right hands to respond, all of the below locations
32
should be primed, and if the participants are using their left hands to respond, the locations that
should be primed are the below locations center and left.
First analyzing the hammer/nail reference object/located object pairing, a 2 orientation
(left, right) X 2 spatial relation (above, below) X 3 placement (left, center, right) X 2 hand of
response (left, right) mixed-model ANOVA revealed there was no significant main effect of
orientation, F(1, 38) = 0.370, p = .546. There were, however, main effects of spatial relation,
[F(1, 38) = 36.13, p < .001, ηp2 = 0.487], with above (M = 610.69, SD = 139.85) being responded
to quicker than below (M = 689.82, SD = 177.21), and placement, [F(2, 76) = 13.31, p < .001,
ηp2 = 0.250], with the center (M = 636.80, SD = 156.45) being responded to the quickest,
followed by the right (M = 650.98, SD = 154.76) and left (M = 663.00, SD = 164.37) locations,
respectively. Pairwise comparisons indicated that the center placement was significantly quicker
than the left placement (p < .023). There was also a marginally significant main effect of hand of
response, with the right hand (M = 613.30, SD = 119.90) being significantly quicker than the left
hand (M = 687.21, SD = 183.45), F(1, 38) = 3.20, p = .081, ηp2 = .078. There were no significant
interactions (all p’s > .142). No evidence of Carlson et al.’s (2006) functionality effects were
found using a bimanual response with the hammer and nail.
Now switching to analyzing the toothbrush/toothpaste reference object/located object
pairing with a bimanual response, once again a 2 orientation (left, right) X 2 spatial relation
(above, below) X 3 placement (left, center, right) X 2 hand of response (left, right) mixed-model
ANOVA was conducted. There were no significant main effects of object orientation, [F(1, 38) =
.508, p = .480], or placement, F(2, 76) = 1.19, p = .311. This means that the toothbrush/
toothpaste pairing did not show evidence for using geometry to compute spatial relations as was
the case with the hammer/nail pairing. There was, however, a significant main effect of spatial
33
relation, with above (M = 594.22, SD = 156.43) being responded to significantly faster than
below (M = 697.97, SD = 193.77), [F(1, 38) = 73.54, p < .001, ηp2 = .659], and a significant
effect of hand of response, with right hand responses (M = 594.34, SD = 125.72) being
significantly faster than left hand responses (M = 697.85, SD = 201.42), F(1, 38) = 5.17, p =
.029, ηp2 = .120. As with the hammer and nail, no evidence of Carlson et al.’s (2006)
functionality effect was found. Separate analyses were conducted to look specifically at
affordance effects.
In order to check for affordance effects for both the hammer and the toothbrush, four
separate 2 orientation (left, right) X 2 hand of response (left, right) ANOVAs were used (for
hammer above, hammer below, toothbrush above, and toothbrush below), as these were the
analyses that Tucker and Ellis (1998) used. Unfortunately, none of the analyses yielded any
significant affordance effects, as none of the interactions was significant (all p’s > .155).
One last analysis was conducted on gender, as in Study 1, to make sure any potential sex
differences in tool use weren’t affecting the data. Once again, no significant differences between
male and female participants were found (all p’s > .15).
Discussion
In Study 2, the task of Carlson et al. (2006) was combined with the response modality
and theory behind Tucker and Ellis (1998). Based on the findings of Carlson et al. (2006) and
Tucker and Ellis (1998), it was predicted that the located objects that follow the rules of
geometry (center of the reference object), functionality between reference and located objects
(ideal locations for interaction between reference and located objects), and affordances between
the participant and the reference object (hand of response matches handle of object) would be
facilitated. This was predicted because the affordance effect of Tucker and Ellis (1998)
34
demonstrated that actions were primed by looking at pictures of objects with graspable handles.
This was the reason the present study used a bimanual response—in an attempt to see if these
affordances would operate under Carlson et al.’s (2006) task of computing spatial relations.
However, the results of this study did not turn out as predicted. There was no evidence of
affordance effects for graspable sides of objects, no evidence of functionality effects between
reference and located objects; however, there was evidence for the role of geometry in
determining spatial relations when using the hammer and nail.
After failing to replicate the affordance effects of Tucker and Ellis (1998) in Klein’s
(2011) study, the sizes of the images were changed from being the smaller size of Carlson et al.’s
(2006) objects to being closer to the real-life sizes of the objects. Tucker and Ellis (1998) also
tried to approximate the real-life sizes of their objects in their study, and it was believed that this
could be a big help in finding affordance effects—does an object need to be of a graspable size in
order to activate affordances? Unfortunately, this modification didn’t lead to affordance effects
in the current study. The present study provides no evidence for affordances or for Tucker and
Ellis’s (1998) notion of the automatic activation of reaching and grasping movements for each
hand when a person perceives an object that he/she could interact with. Affordances were not
found with either the hammer or the toothbrush, at either orientation.
35
CHAPTER 4: STUDY 3
Study 3 was conducted in order to determine the role of cognitive resources in the
hypothesized functionality and affordances effects from Study 1 and Study 2. This study
therefore added a “cognitive load” task to the sentence-picture completion task, in an attempt to
tax the participants’ cognitive resources.
Participants performed the task from Study 2 under conditions of both cognitive load and
no cognitive load. The “no cognitive load” condition was identical to Study 2 except only the
toothpaste and toothbrush combination was used (i.e., hammer and nail was be used) to eliminate
potential fatigue from too many trials. In the “cognitive load” condition, participants saw a grid
of dots presented on the screen (a dot memory test). They were instructed to try to remember the
locations of the dots. They were then presented with a sentence on the screen (e.g., the toothpaste
is above/below the toothbrush), after which a picture display was presented containing both the
reference and located objects. The participants’ task was again to verify whether the sentence
was an accurate description of the picture by making a bimanual yes or no response using the
keyboard. At the end of each trial, participants were then asked to select the arrangement of dots
they were supposed to remember from the beginning of the trial from a multiple choice list.
It is important to note that the image used in Study 3 (toothbrush) had the potential to
find both Carlson et al.’s (2006) functionality effect (hypothesized in Study 1 of the current
study) and Tucker and Ellis’s (1998) affordance effect (hypothesized in Study 2 of the current
study) because it had bristles on one side of the object and a handle on the other side of the
object. The process from the participants’ perception of the toothbrush to making their bimanual
response on the keyboard could potentially use cognitive resources at several different stages.
36
Based on the theories of Carlson et al. (2006) and Tucker and Ellis (1998), a model for where
these cognitive resources are used during the process will now be proposed.
A participant first perceives the visual object (toothbrush) presented on the computer
screen. After this, the object needs to be identified. If the object has a function (as a toothbrush
does), then the function of the object is also be identified. At this point, two things happen: 1)
spatial attention is allocated to the functional side of the object, and 2) appropriate actions toward
the object are computed. This causes the hand of response that matches the appropriate action
toward the object to be primed. After this, the participant computes the spatial relation between
the reference object (toothbrush) and the located object (toothpaste). The participant then decides
if the spatial relation he/she computed matches the sentence that was presented to them. Finally,
a bimanual response is made on the keyboard.
During this process, cognitive resources could be needed at several stages. Both
identifying the object and identifying the function of the object require knowledge to be
extracted from long-term memory and entered into working memory in order to make a
selection. The important stage for the functionality effect is the stage at which spatial attention is
focused on the bristle side of the toothbrush. This focus of attention is determined by the
perceived functional interaction between the toothbrush and the toothpaste. The important stage
for the affordance effect is the stage at which appropriate actions towards the objects are
computed. Although Gibson (1979) would argue that the function of an object does not need to
be known in order to grant affordances, Tucker and Ellis (1998) acknowledged that the function
of an object was important in order to understand which kind of action to take towards the object.
The computation of which actions are appropriate and the selection of which action is
appropriate should both consume cognitive resources such as searching through long-term
37
memory for past interactions with the object, selecting actions to move into working memory,
and making a selection from working memory. The stage where the spatial relation between the
reference and located object is computed is obviously going to require cognitive resources in the
form of spatial attention (as discovered in Logan, 1994). Making the decision as to whether the
presented sentence matches the computed spatial relation also requires cognitive resources in the
form of working memory.
A visuo-spatial working memory task in the form of a dot memory test was chosen to be
the distractor task that would increase cognitive load in this study. Creem and Proffitt (2001)
found that a verbal distractor task interfered with a semantic task, but a visuo-spatial task did not;
however, they also found that a visuo-spatial distractor task interfered with a visuo-spatial task,
but a semantic task did not. A visuo-spatial working memory task was selected for the current
study because of the nature of Carlson et al.’s (2006) sentence-picture completion task, which
requires the computation of spatial relations. If the allocation of spatial attention to the functional
side of an object and the spatial attention consumed while computing spatial relations between
the reference and located objects are what moderated Carlson et al.’s (2006) functionality effect,
and a participant’s spatial attention abilities are taxed through the use of a visuo-spatial distractor
task, then the functionality effects should disappear under these conditions. Likewise, if
cognitive resources such as working memory were recruited in order to determine the
appropriate action to take with the reference object and select the appropriate hand of response,
then the affordance effect should also be diminished. If cognitive resources were not recruited
for the affordance effect, then the affordance effect should remain.
Method
Participants
38
The participants of Study 3 were 30 psychology student volunteers (19 females, 11
males) who were tested individually in one 60 minute session and received partial course credit
as compensation. All participants had normal or corrected-to-normal vision.
Apparatus
The apparatus of Study 3 was the same as Study 2, except a second computer screen was
used to display the dot memory grids on a PowerPoint presentation.
Stimuli
The stimuli used in Study 3 were the same as the stimuli used in Study 2, except there
was no hammer and nail stimuli. There were 144 toothbrush/toothpaste trials in the “no cognitive
load” condition (2 spatial relation: above/below x 2 orientation: left/right x 3 locations per spatial
relation: left/center/right x 12 repetitions). In the “cognitive load” condition, dot memory grids
were presented before the sentence-picture verification task, and a multiple choice test question
containing four dot memory grids to choose from appeared at the end of the sentence-picture
verification task. Each dot memory grid was a 5 x 5 block of cells that contained between two
and seven dots. Each cell of the grid was 1.27 cm x 1.27 cm. An example of a dot memory grid
can be found in Figure 6.
Design
This experiment consisted of a 2 cognitive load (load vs. no load) X 2 spatial relation
(above vs. below) X 2 orientation (left vs. right) X 3 locations per spatial relation (left vs. center
vs. right) within-subjects design. There were 12 repetitions per location for a total of 288 trials in
this experiment. The cognitive load vs. no cognitive load conditions were blocked and counterbalanced across subjects.
Procedure
39
The procedure for Study 3 was the same as the procedure for Study 2, except participants
were presented with a dot memory grid for 1000 ms before they were presented with the
sentence-picture verification task, and they were given a 4-item multiple-choice question at the
end of each sentence-picture verification task to select the dot arrangement that they
remembered.
Results
The same analyses that were used for Study 1 and Study 2 were also used for Study 3,
except the hammer and nail were not used, and the cognitive load vs. no cognitive condition was
analyzed as well. In the “load” condition, trials on which participants performed incorrectly on
the dot memory task were not analyzed with the data (resulting in 6.8% data removal). As in
both previous studies, all errors on the sentence-picture completion task (e.g., responded yes
when the correct response was no) were removed from the data set. Accuracy for the participants
on the sentence-picture completion task was high once again, with an average error rate of only
3.20% in the load condition and 4.88% in the no load condition, t(29) = -3.02, p = .005. In order
to remove outliers, reaction times that were further than 2.5 standard deviations away from each
participant’s mean reaction time were removed from the analysis and replaced with each
participant’s mean response time. This resulted in 3.5% data replacement from the no load
condition and 3.9% data replacement from the load condition. With the overlap between grid
errors and sentence-picture completion task errors, total data removal was 2.87% for the no load
condition and 5.34% for the load condition. Of the remaining data, only correct yes responses
were analyzed (as in Carlson et al., 2006).
It was predicted that when the bristles of the toothbrush were on the right, and the
toothpaste was above the bristles, that location should be facilitated in the “no cognitive load”
40
condition; however, in the “cognitive load” condition, that location should not be facilitated as
compared to the left location—geometry should be the fastest. Under conditions of cognitive
load, it was predicted that no functionality effects should be seen for any locations above or
below the toothbrush; therefore, the reaction times to the left and right placements of the
toothbrush should be equal. Also, it was predicted that if affordances of functional objects recruit
cognitive resources [as Creem and Proffitt (2001) and, to a lesser extent, Tucker and Ellis (1998)
claim they do] then affordance effects should be present in the “no cognitive load” condition but
absent in the “cognitive load” condition.
As previously stated, the hammer and nail pairing was not used in this study; only the
toothbrush and toothpaste pairing was used. This decision was made in order to ensure that both
the load and no load conditions would be able to be performed by each participant in one session
and to control for fatigue. For analyzing the toothbrush and toothpaste pairing, first a 2 cognitive
load (load, no load) X 2 orientation (left, right) X 2 spatial relation (above, below) X 3 placement
(left, center, right) X 2 hand of response (left, right) mixed-model ANOVA was conducted.
Results indicated that there were no main effects of orientation, [F(1, 28) = .017, p = .897], or
hand of response, F(1, 8) = .536, p = .470. There was a significant main effect of cognitive load,
with participants taking significantly longer to respond in the load condition (M = 749.67, SD =
213.33) than in the no load condition (M = 628.72, SD = 180.11), F(1, 28) = 15.07, p = .001, ηp2
= .350. There was also a significant main effect of spatial relation, with above responses (M =
628.21, SD = 179.96) being significantly quicker than below responses (M = 750.18, SD =
225.58), F(1, 28) = 52.05, p < .001, ηp2 = .650. The last main effect was a main effect of
placement, with the center being responded to the quickest (M = 673.77, SD = 191.35), followed
by the left (M = 687.19, SD = 197.40) and the right (M = 706.64, SD = 202.35), respectively,
41
F(2, 56) = 4.36, p = .017, ηp2 = .135. Pairwise comparisons indicated that the center placement
was significantly quicker than the right placement (p = .028).
There were also several significant interactions in this analysis. The spatial relation x
hand of response interaction was significant, with the right and left hand responses having an
equal reaction time in the above spatial relation, but the right hand response being slower in the
below spatial relation, F(1, 28) = 6.43, p = .017, ηp2 = .187 (see Figure 7). There was also a
significant three-way interaction between cognitive load, spatial relation, and hand of response,
with the longest reaction times being seen in the load condition with the below spatial relation
and right hand responses, F(1, 28) = 6.04, p = .02, ηp2 = .178 (see Figures 8 and 9). Another
marginally significant three-way interaction was found between orientation, spatial relation, and
hand of response, with there being a small trend for a potential affordance effect (left hand
responses are quicker when the bristles are on the right and right and responses are quicker when
the bristles are on the left, thus matching handle and hand of response), but only in the above
spatial relation, F(1, 28) = 3.69, p = .065, ηp2 = .116 (see Figures 10 and 11). Lastly, there was a
significant four-way interaction between load, placement, orientation, and hand of response, F(2,
56) = 8.30, p = .001, ηp2 = .229. In this interaction, there appears to be some inconsistent
evidence for the effects of geometry and affordances in the “load” condition. As an example of
potential geometry effects, when the toothbrush is oriented to the left with a left hand response
and when the toothbrush is oriented to the right with a right hand response, the center placement
is the quickest. As for potential affordance effects, when the handle is on the left and the left
hand is making the responses, all three placements are quicker than the right hand responses. As
for the no load condition, there is a trend for functionality effects or a Simon effect (i.e., the left
hand responding quicker when the located object is on the left) when the object is oriented to the
42
left and the participant is responding with their left hand. A Simon effect occurs when the
stimulus is in the same relative location (i.e., on the same side) as the response. Therefore, when
the located object (e.g., the toothpaste) is on the same side as the hand of response, there could
be facilitation of responding for that hand (according to the Simon effect). Both orientations
using the right hand and the right orientation using the left hand show trends for geometry effects
(see Figures 12 and 13). The most consistent effects in this interaction are load taking longer to
respond to than no load, and consistent trends for geometry effects. Further analyses were done
to determine the source of this interaction and to see if the described trends are significant.
To examine the source of this interaction, each of the clustered “triads” from Figures 12
and 13 were analyzed separately to try to determine if spatial relation and placement had any part
in driving the effect (i.e., looking for functionality and geometry effects). So for example, the
load condition, Figure 12, has four triads (which will be referred to as triads A, B, C, and D,
respectively) that each refer to a different orientation/hand of response pairing of the object.
Figure 13, the no load condition, also has four triads which will be referred to in the same
manner. First examining Triad A from Figure 12 (load, left orientation, left hand), a 2 spatial
relation (above, below) X 3 placement (left, center, right) ANOVA was conducted. Results
indicated that there were no significant main effects of either spatial relation, [F(1, 14) = .651, p
= .433], or placement, [F(2, 28) = .651, p = .137], and the interaction was also not significant,
F(2, 28) = .214, p = .808. For Triad B (load, left orientation, right hand), the same analysis was
conducted. Results indicated that there was a significant main effect of spatial relation [F(1, 14)
= 21.39, p < .001], with above (M = 673.57, SD = 185.58) being responded to quicker than below
(M = 865.79, SD = 267.32); however, there was no significant effect of placement, [F(2, 28) =
1.04, p = .365], or an interaction, [F(2, 28) = .126, p = .882]. For Triad C (load, right orientation,
43
left hand), there was again a significant effect of spatial relation [F(1, 14) = 6.15, p = .026], with
above (M = 686.90, SD = 181.00) being responded to quicker than below (M = 753.33, SD =
199.00); however, there was no significant effect of placement, [F(2, 28) = .647, p = .531], or an
interaction, [F(2, 28) = 1.19, p = .319]. For Triad D (load, right orientation, right hand), there
was once again a significant effect of spatial relation [F(1, 14) = 14.74, p = .002], with above (M
= 697.47, SD = 188.09) being responded to quicker than below (M = 857.30, SD = 269.78);
however, there was no significant effect of placement, [F(2, 28) = 2.59, p = .093], or an
interaction, [F(2, 28) = .348, p = .709]. There were no significant effects of placement or
interactions in the load condition.
Moving on to the no load condition, Triad A of Figure 13 (no load, left orientation, left
hand response), a 2 spatial relation (above, below) X 3 placement (left, center, right) ANOVA
was again conducted. Results indicated that there was a significant main effect of spatial relation
[F(1, 14) = 10.88, p = .005], with above (M = 561.00, SD = 158.99) being responded to quicker
than below (M = 665.19, SD = 217.73). There was also a significant main effect of placement,
with the left being responded to the quickest (M = 653.51, SD = 139.78), followed by the center
(M = 618.97, SD = 208.52), and then the right (M = 656.81, SD = 216.79), [F(2, 28) = 5.46, p =
.01]. Pairwise comparisons indicated that there was a significant difference between left and
right placements (p = .014). There was no interaction, [F(2, 28) = .159, p = .854]. The main
effect of placement follows the pattern which would be predicted by functionality effects
(although not in the location optimal for interaction as there was no significant interaction) or by
a Simon effect (Figure 14). For Triad B (no load, left orientation, right hand response), there was
a significant main effect of spatial relation [F(1, 14) = 49.16, p < .001], with above (M = 549.28,
SD = 138.90) being responded to quicker than below (M = 739.54, SD = 209.06). There was also
44
a significant main effect of placement, with the center being responded to the quickest (M =
591.97, SD = 125.34), followed by the right (M = 646.01, SD = 194.69), and then the left (M =
695.27, SD = 201.94), [F(2, 28) = 5.10, p = .013]. Pairwise comparisons indicated that there was
a significant difference between left and center placements (p = .031). There was no interaction,
[F(2, 28) = 1.81, p = .182]. The main effect of placement is consistent with using geometry to
compute spatial relations (see Figure 15). For Triad C (no load, right orientation, left hand
response), results indicated that there was a significant main effect of spatial relation [F(1, 14) =
13.86, p = .002], with above (M = 557.46, SD = 139.88) being responded to quicker than below
(M = 674.98, SD = 203.10); however, there was no significant effect of placement, [F(2, 28) =
1.16, p = .228], or an interaction, [F(2, 28) = .613, p = .549]. Finally, for Triad D (no load, right
orientation, right hand response), there was once again a main effect of spatial relation, [F(1, 14)
= 22.87, p < .001], with above (M = 582.62, SD = 159.80) being responded to quicker than below
(M = 699.69, SD = 201.23); however, there was no significant effect of placement, [F(2, 28) =
1.04, p = .366], or an interaction, [F(2, 28) = .986, p = .386]. The no load condition only showed
significant effects when the toothbrush was oriented to the left; however, with a left hand
response, a marginally significant trend for a function effect (or a Simon effect) was found, and
with a right hand response, evidence for the use of geometry to compute spatial relations was
found.
The next analyses examined load vs. no load in the same analyses to compare them
directly, as it seems like cognitive load might be the driving force behind the four-way
interaction that was found. The following analyses compared Triad A from Figure 12 (load) with
Triad A from Figure 13 (no load), Triad B from Figure 12 with Triad B from Figure 13, etc. The
data were analyzed using four separate 2 load (load, no load) X 2 spatial relation (above, below)
45
X 3 placement (left, center, right) within-subjects ANOVAs, one for each triad comparison. For
Triad A (left orientation, left hand response), there was a significant main effect of cognitive
load, [F(1, 14) = 6.80, p = .021], with participants taking significantly longer to respond in the
load condition (M = 731.50 , SD = 198.68) than in the no load condition (M = 613.10, SD =
188.36). Because the load condition analyzed alone revealed no significant effects for Triad A,
the following significant effects were driven by the no load condition. There was a significant
main effect of spatial relation, [F(1, 14) = 4.92, p = .044], with above responses (M = 639.18, SD
= 174.18) being quicker than below responses (M = 705.41, SD = 212.85). There was a
marginally significant effect of placement [F(2, 28) = 3.28, p = .052], with participants
responding the quickest in the left placement (M = 658.91, SD = 181.42), followed by the center
placement (M = 660.89, SD = 188.44), and the right placement (M = 697.10, SD = 210.66).
Pairwise comparisons indicated that the left placement was only marginally significantly
different from the right placement (p = .093) (see Figure 16). This is consistent with a pattern of
responding due to either functionality or a Simon effect. There was a significant load x spatial
relation interaction, with participants responding the quickest in the no load condition with the
above spatial relation and slowest in the load condition with the below spatial relation, F(1, 14) =
6.46, p = .023 (see Figure 17). This interaction was further explored using paired-samples ttests. Results indicated that there was a significant difference between above and below in the
“no load” condition, [t(14) = -3.18, p = .007], and there was a significant difference between
load and no load in the above condition, t(14) = 3.55, p = .003. Participants respond significantly
quicker to above in the no load condition. There was also a significant load x placement
interaction, with participants in the load condition showing a pattern of responding consistent
with the effects of geometry and participants in the no load condition showing a pattern of
46
responding consistent with functionality or Simon effects (i.e., the left placement was the
quickest), F(1, 14) = 4.43, p = .021 (see Figure 18). To assess this interaction, two one-way
ANOVAs were conducted. In the load condition, there was no significant effect of placement,
F(2, 28) = 2.13, p = .137. In the no load condition, there was a significant effect of placement,
with the left being responded to the quickest (M = 563.52, SD = 130.71), followed by the center
(M = 618.97, SD = 198.74), and then right (M = 656.81, SD = 185.93), F(2, 28) = 5.46, p = .010.
Pairwise comparisons indicated that the left and right placements were significantly different
from each other (p = .014). There was no significant relation x placement interaction, [F(2, 28) =
.039, p = .962], nor was there a load x placement x relation interaction, F(2, 28) = .319, p = .730.
These analyses of Triad A revealed that there was a significant Simon effect when the toothbrush
was oriented to the left and using a left hand response; however, this effect was only present in
the no load condition which is unsurprising given that none of the effects were significant when
the load condition was analyzed alone.
Triad B (left orientation, right hand response) was also assessed using a 2 load (load, no
load) X 2 spatial relation (above, below) X 3 placement (left, center, right) within-subjects
ANOVA. There was a significant main effect of cognitive load, [F(1, 14) = 7.25, p = .018], with
participants taking significantly longer to respond in the load condition (M = 769.68 , SD =
226.43) than in the no load condition (M = 644.41, SD = 173.97). Given that there was a
significant main effect of spatial relation in both the load and no load conditions of Triad B when
they were analyzed separately, it follows that there was also a significant main effect of spatial
relation in this instance, [F(1, 14) = 40.93, p < .001], with above responses (M = 611.42, SD =
162.24) being quicker than below responses (M = 802.67, SD = 238.18). The main effect of
placement, which was significant for the no load condition analyzed alone, was no longer
47
significant, F(2, 28) = 1.52, p = .237. The load x spatial relation interaction was also not
significant, [F(1, 14) = .003, p < .958]. There was, however, a significant interaction between
load and placement, with participants in the no load condition showing a pattern consistent with
the effects of geometry, F(2, 28) = 4.43, p = .021 (see Figure 19). To assess this interaction, two
one-way ANOVAs were conducted. In the load condition, there was no significant effect of
placement, F(2, 28) = 1.04, p = .365. In the no load condition, there was a significant effect of
placement, with the center being responded to the quickest (M = 591.97, SD = 115.86), followed
by the right (M = 646.01, SD = 185.68), and then left (M = 695.25, SD = 191.64), F(2, 28) =
5.09, p = .013. Pairwise comparisons indicated that the left and center placements were
significantly different from each other (p = .031). The spatial relation x placement interaction
was not significant, [F(2, 28) = .711, p = .500], nor was the load x relation x placement
interaction, F(2, 28) = .514, p = .604.
For Triad C (right orientation, left hand response), the same analysis was again conducted
[a 2 load (load, no load) X 2 spatial relation (above, below) X 3 placement (left, center, right)
within-subjects ANOVA]. Results indicated that there was a significant main effect of cognitive
load, [F(1, 14) = 8.81, p = .010], with participants taking significantly longer to respond in the
load condition (M = 720.12, SD = 190.00) than in the no load condition (M = 616.21, SD =
171.49). Given that there was a significant main effect of spatial relation but no other significant
effects for Triad C when load and no load conditions were analyzed separately, it is not
surprising that the combined analysis showed likewise. There was a significant main effect of
spatial relation, [F(1, 14) = 22.37, p < .001], with above responses (M = 622.18, SD = 160.43)
being quicker than below responses (M = 714.16, SD = 201.05). There was no significant main
effect of placement, F(2, 28) = .807, p = .456. None of the interactions was significant: load x
48
relation, [F(1, 14) = .003, p = .958], load x placement, [F(2, 28) = .842, p = .441], relation x
placement, [F(2, 28) = .501, p = .611], load x relation x placement, [F(2, 28) = 1.55, p = .230].
Lastly, for Triad D (right orientation, right hand response), a 2 load (load, no load) X 2
spatial relation (above, below) X 3 placement (left, center, right) within-subjects ANOVA was
again conducted. The results indicated that there was once again a significant main effect of
cognitive load, with participants taking longer to respond in the load condition (M = 777.38, SD
= 228.94) than in the no load condition (M = 641.15, SD = 171.49), F(1, 14) = 6.57, p = .023. As
was the case when Triad D was analyzed separately in both the load and no load conditions,
there was a significant main effect of spatial relation, with participants responding quicker to
above (M = 640.05, SD = 173.95) than to below locations (M = 778.49, SD = 235.50), F(1, 14) =
19.96, p = .001. Although there was no significant effect of placement for Triad D in either the
load or no load conditions when analyzed separately, a significant main effect of placement was
found in this analysis, with participants responding quickest at the center placement (M = 682.36,
SD = 196.52), followed by the left placement (M = 711.72, SD = 206.93), and the right
placement (M = 733.73, SD = 210.73), respectively, F(2, 28) = 4.74, p = .017 (see Figure 20).
None of the interactions was significant: load x relation, [F(1, 14) = 2.22, p = .158], load x
placement, [F(2, 28) = .523, p = .598], relation x placement, [F(2, 28) = .775, p = .470], load x
relation x placement, [F(2, 28) = .454, p = .639].
These analyses, which compared triads in the load condition to triads in the no load
condition, consistently found that the load condition took longer to respond to than the no load
condition, and that above responses are quicker than below responses. There was evidence in two
of the four triads that participants were using geometry to compute spatial relations, and this
effect was driven by the no load condition. One triad revealed evidence of a Simon effect. When
49
the toothbrush was oriented to the left, using a left hand response, responses to the left object
placement were the quickest. This would be consistent with functionality effects if there was an
interaction with spatial relation and the optimal location for interaction was the quickest (i.e.,
above); however, this was not the case.
Once again, a different series of studies were completed to look specifically for
affordance effects. Separate 2 orientation (left, right) X 2 hand of response (left, right) ANOVAs
were done on the toothbrush for both the above and below spatial relations. In the no load
condition, there was no evidence for affordances in either the above or below spatial relation, as
none of the main effects and neither interaction was significant (all p’s > .105). The same was
true in the load condition. None of the main effects and neither interaction was significant (all
p’s > .115). No evidence of affordance effects was found by doing these 2 x 2 ANOVAs, which
were the analyses used by Tucker and Ellis (1998).
Discussion
In Study 3, the same task was used as Study 1 and Study 2, using the response modality
of Study 2 (bimanual), with the addition of a spatial distractor task to tax cognitive resources. It
was predicted that the results of the “no load” condition should be the same as the results of
Study 2, as they were the same except that participants in Study 3 also completed the trials of the
load condition. This held true only somewhat. Neither Study 2 nor the no load condition of the
current study found the predicted effects of affordances; however the no load condition of Study
3 found some evidence of using geometry to compute spatial relations, and also found some
evidence for the Simon effect in one instance. In Study 2, the toothbrush/toothpaste pairing
yielded none of these effects. While the no load condition of Study 3 yielded one significant
effect for geometry when the toothbrush was oriented to the left using a right hand response and
50
a significant effect for a Simon effect when the toothbrush was oriented to the left using a left
hand response, there was no strong evidence for Carlson et al.’s (2006) functionality effect. The
facilitation of response for the left placement when the toothbrush was oriented to the left could
be due to Carlson et al.’s (2006) theory of focusing attention on the functional side of the object;
however, there was no evidence that the optimal location for interaction between the toothbrush
and toothpaste (i.e., above, left) was facilitated more than the location that was not optimal for
interaction (i.e., below, left). Because of this, it is more likely that participants were experiencing
a facilitation of response due to the located object (i.e., the toothpaste) being on the same side as
the hand of response (i.e., a Simon effect). That being said, it is unclear as to why this effect
would only occur for the left hand/left orientation and not for the right hand/right orientation.
In the load condition of the current study, it was predicted that if cognitive resources play
a role in the computation of spatial relations, there should be no effects of facilitation for either
the functionality effect or the affordance effect. No solid evidence of an affordance effect was
found in either the load or no load conditions of this study or in Study 2, so the role of cognitive
resources in affordance effects cannot be examined in the way that was predicted. There is,
however, some evidence of cognitive load affecting the facilitation of located object placement.
In the no load condition, there was a significant effect of geometry (when the toothbrush was
oriented to the left, using a right hand response), and there was also a significant Simon effect
(when the toothbrush was oriented to the left, using a left hand response). In the load condition,
however, there were no significant effects of placement—no evidence for geometry,
functionality, or a Simon effect. Because of this, the results from the no load condition (that
indicated that participants were using the rules of geometry to compute spatial relations or
focusing their attention on the functional/salient side of the object) disappeared under conditions
51
of cognitive load. This provides some evidence that the spatial distractor task caused participants
to be cognitively taxed to the extent that they were no longer using their usual rules (i.e., either
geometry or focusing attention on the functional/salient side) to compute spatial relations. This is
consistent with Logan’s (1994) theory that attention is necessary to compute spatial relations.
Because the hypothesis of this study was that cognitive load would decrease affordance and
functionality effects when computing spatial relations, and no affordance or functionality effects
were found, this does not support the original hypothesis. However, it does provide some
evidence that cognitive resources are required for focusing attention on the salient side of an
object, and cognitive resources are even required for using geometry to compute spatial relations.
This is consistent with Creem and Proffitt’s (2001) theory that participants can still perform tasks
under conditions of cognitive load, just not in the ideal manner (i.e., participants could still grasp
a spatula, but not in a manner appropriate for its use).
52
CHAPTER 5: GENERAL DISCUSSION
The three studies of this paper were designed in an attempt to study the role of cognitive
resources (especially spatial attention) in the previously found affordance effects and
functionality effects when computing spatial relations. These studies used pictures of objects that
have two functional sides (one side graspable and one side interacting with other objects in the
environment) and a sentence-picture completion task in an attempt to learn more about how
people use attention and affordances when viewing an object and discerning spatial relations
around that object. In other words, the task of Carlson, Regier, Lopez, and Corrigan (2006) was
combined with the response modality and theory behind Tucker and Ellis (1998). Furthermore,
because the sentence-picture verification task used in all three studies required the computation
of spatial relations, the addition of a spatial distractor task was used in an attempt to discover the
role of spatial attention in functionality and affordance effects during a spatial task. If spatial
resources were recruited during the task, it could have affected the way spatial relations were
computed when using a functional object or an object with a graspable handle.
Study 1 was intended to replicate the functionality effects of Carlson et al. (2006) using
different objects and the computation of both spatial locations above and below. Based on the
findings of Carlson et al. (2006), it was predicted that the located objects that follow the rules of
geometry (center of the reference object) and functionality between reference and located objects
(prime locations for interaction between reference and located objects) would be the locations
with the most facilitation. However, while there was evidence for the role of geometry in
determining spatial relations, there was no evidence of functionality effects between reference
and located objects.
53
One of the purposes of the present study was to test whether the Attentional Vector Sum
Model (AVS) (Regier & Carlson, 2001), which predicts acceptability ratings for spatial terms,
still made the correct predictions when using a vocal response as opposed to a unimanual
response (as used by Carlson et al., 2006). The findings of the present study differ from the
findings of Carlson et al. (2006), who used the AVS model to explain their findings. They
claimed to have demonstrated that the computation of spatial relations was moderated by the
function of the reference object in relation to the located object. Carlson et al. (2006) found
evidence that the functional (spout) side of a watering can was responded to quicker than the
other locations when a plant was placed in a position that allowed for interaction between itself
and the watering can. The present study did not find this effect, instead finding only an effect of
the geometric center being responded to the quickest. As mentioned earlier, it is possible the
functionality effects are intricately tied to manual responses, as people generally interact with the
objects with their hands. Also, there is an additional step involved in manual responses as
compared to vocal responses, as a participant needs to remember which hand goes with which
response. A more likely explanation could be that, in this particular task, participants were not
interpreting spatial relations with respect to the object’s function, but instead simply using
geometry.
Study 2 then used the same task with a bimanual response in order to assess whether
Tucker and Ellis’s (1998) affordance effects would occur using the task of Carlson et al. (2006),
which required the computation of spatial relations. It was predicted that in addition to Carlson et
al.’s (2006) functionality effects, affordance effects would be found when the hand of response
matched the side of the handle on the presented object. This was predicted because the
affordance effect of Tucker and Ellis (1998) demonstrated that actions were primed by looking at
54
pictures of objects with graspable handles. By showing pictures of a range of common objects
with handles (such as a frying pan), Tucker and Ellis (1998) found that the side of the object that
had a handle would prime the hand of response on the same side. They interpreted this as
evidence that visual objects can grant affordances even when the participant has no intention of
actually acting upon the objects. Because this task relied on priming either the left or right had to
respond, their results were found when using a bimanual response but not when using a
unimanual response. This is the reason the present study used a bimanual response—in an
attempt to see if these affordances would operate under Carlson et al.’s (2006) task. However,
the results of this study did not turn out as predicted. There was no evidence of affordance effects
for graspable sides of objects for either the hammer or the toothbrush, at either orientation.
One reason for the lack of an affordance effect in Study 2 could be because Tucker and
Ellis (1998) used a task that did not require the computation of spatial relations. Their task was a
simpler task, where participants simply had to decide if the presented object was upright or
inverted. It is possible that the facilitation benefit granted to a participant because of an
affordance only lasts a very short amount of time, and if the participant is computing a spatial
relation during that time, the affordance effect might be lost or pushed out due to interference. It
would be interesting to check for affordances using a simpler task that required less cognitive
processing to determine if this notion is true.
Study 3 was designed to add a spatial distractor task on top of the already established task
and response modality of Study 2. The distractor task was added in order to test whether spatial
attention was recruited for the functionality and affordance effects when computing spatial
relations. If spatial attention or other spatial cognitive resources were recruited, then these effects
should disappear under cognitively taxing conditions. If the effects did disappear, then the
55
hypothesis that spatial cognitive resources were recruited when participants were processing the
functionality of the object (and how they could interact with that object) would be supported.
Such evidence could potentially shed light on the way spatial relations are computed when using
a functional object or an object with a graspable handle. However, no affordance or functionality
effects were found. A consistent result in Study 3 was that participants took longer to respond
under the load condition than the no load condition. Also, although not consistent across
orientation and hand of response, there was one instance of a Simon effect disappearing under
conditions of cognitive load. Presumably, participants were no longer able to successfully focus
their spatial attention when it was taxed by the spatial distractor task.
There was also evidence that the usually reliable effect of the geometric center being
responded to the quickest broke down under conditions of cognitive load. As stated previously,
this is consistent with Creem and Proffitt’s (2001) theory that participants can still perform tasks
under conditions of cognitive load (a sentence-picture completion task in this case), just not in
the ideal manner (i.e., participants may not have been processing the purpose or function of the
object under conditions of cognitive load—just responding the best they could under taxing
conditions). This provides evidence that cognitive resources are also recruited when using the
principles of geometry to compute spatial relations, which supports the theory of Logan (1994).
Although a spatial distractor task was used in this study, it would also be interesting to look at a
verbal distractor task in the future. Creem and Proffitt (2001) indicated that their semantic
distractor task influenced the appropriate grasping of objects (spatulas) in front of the
participants, so it might be interesting to see if a verbal distractor task would influence the results
of the current study using Carlson et al.’s (2006) sentence-picture completion task.
56
The current series of studies showed no evidence for the functionality effects of Carlson
et al. (2006) or the affordance effects of Tucker and Ellis (1998). However, there was evidence
that the principles of geometry are used to compute spatial relations, and that this process
requires attention. When participants’ spatial attention abilities were taxed, all facilitation of
located object placements that were present in the no load condition disappeared. As the current
studies do not hold the answer for the role of cognitive resources in the processing of
functionality and affordances, future research will need to be conducted in order to contribute to
the greater understanding of how affordances and object function work together during the
computation of spatial relations.
57
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60
Figure 1
APPENDIX A: FIGURES
Proportion of spatial preposition use in a production task in which participants were shown
images of reference objects with located objects at various positions surrounding the reference
object. Participants were asked to describe the relation of the located object to the reference
object. Each cell corresponds to a different location of the located object. Figure 1a corresponds
to the use of vertically oriented terms such as above, below, and over. Figure 1b corresponds to
the use of horizontally oriented terms such as left, right, and beside. Darker shaded cells imply a
greater use of these terms (Hayward & Tarr, 1995).
61
Figure 2
The attentional vector-sum (AVS) model with modifications for predicting spatial relations of
functional objects in panel f (Carlson, Regier, Lopez, and Corrigan, 2006).
62
Figure 3
Solid line = Strong function-induced attention
Dotted line = Moderate function-induced attention
Dashed line = No function-induced attention (geometry)
A simulation of the influences of functionality and geometry on an object with a functional side
(a toothbrush) (Carlson, Regier, Lopez, and Corrigan, 2006).
63
Figure 4
The reference object and 10 different located object locations used by Carlson, Regier, Lopez,
and Corrigan (2006).
64
Figure 5
510
Reaction Time (ms)
500
490
480
470
Left Orientation
460
Right Orientation
450
440
430
Above
Below
Spatial Relation
Reaction times (ms) in Study 1, using the toothbrush, for the interaction between object
orientation and spatial relation.
Figure 6
This is an example of a dot memory grid. Participants’ task is to memorize the location of the
dots and remember them at the end of a trial by selecting a grid from a multiple choice test item.
65
Figure 7
850
Reaction Time (ms)
800
750
700
Left Hand
650
Right Hand
600
550
500
Above
Below
Spatial Relation
Reaction times (ms) in Study 3, using the toothbrush, for the interaction between spatial relation
and hand of response.
66
Figure 8
900
Reaction Time (ms)
850
800
750
700
Above
650
Below
600
550
500
Left Hand
Right Hand
Hand of Response
Reaction times (ms) in Study 3, using the toothbrush, for the interaction between spatial relation,
cognitive load, and hand of response (load condition).
Figure 9
900
Reaction Time (ms)
850
800
750
700
Above
650
Below
600
550
500
Left Hand
Right Hand
Hand of Response
Reaction times (ms) in Study 3, using the toothbrush, for the interaction between spatial relation,
cognitive load, and hand of response (no load condition).
67
Figure 10
850
Reaction Time (ms)
800
750
Left Hand
700
Right Hand
650
600
Left
Right
Object Orientation
Reaction times (ms) in Study 3, using the toothbrush, for the interaction between spatial relation,
object orientation, and hand of response (above condition).
Figure 11
850
Reaction Time (ms)
800
750
Left Hand
700
Right Hand
650
600
Left
Right
Object Orientation
Reaction times (ms) in Study 3, using the toothbrush, for the interaction between spatial relation,
object orientation, and hand of response (below condition).
68
Figure 12
850
Reaction Time (ms)
800
750
700
650
Left
Center
600
Right
550
500
Left Hand
Right Hand
Left Orientation
(Handle on Right)
Left Hand
Right Hand
Right Orientation
(Handle on Left)
Orientation and Hand of Response
Reaction times (ms) in Study 3, using the toothbrush, for the interaction between load,
orientation, placement, and hand of response (load condition).
69
Figure 13
850
Reaction Time (ms)
800
750
700
Left
650
Center
600
Right
550
500
Left Hand
Right Hand
Left Orientation
(Handle on Right)
Left Hand
Right Hand
Right Orientation
(Handle on Left)
Orientation and Hand of Response
Reaction times (ms) in Study 3, using the toothbrush, for the interaction between load,
orientation, placement, and hand of response (no load condition).
70
Figure 14
750
Reaction Time (ms)
700
650
600
Above
550
Below
500
450
400
Left
Center
Right
Object Placement
Mean reaction times (ms) for the no load condition with left hand responses as a function of spatial
relation and located object placement of the toothbrush, oriented to the left (Triad A).
Figure 15
850
Reaction Time (ms)
800
750
700
650
600
Above
550
Below
500
450
400
Left
Center
Right
Object Placement
Mean reaction times (ms) for the no load condition with right hand responses as a function of spatial
relation and located object placement of the toothbrush, oriented to the left (Triad B).
71
Figure 16
850
Reaction Time (ms)
800
750
700
650
600
Above
550
Below
500
450
400
Left
Center
Right
Object Placement
Means reaction times (ms) for the marginally significant effect of placement for the load/no load
comparison (as a function of spatial relation) in Triad A (left orientation, left hand response).
Figure 17
850
Reaction Time (ms)
800
750
700
650
600
Load
550
No Load
500
450
400
Above
Below
Spatial Relation
Mean reaction times (ms) for the interaction between load and spatial relation, for left hand
responses to the toothbrush, oriented to the left (Triad A).
72
Figure 18
850
Reaction Time (ms)
800
750
700
650
600
Load
550
No Load
500
450
400
Left
Center
Right
Located Object Position
Mean reaction times (ms) for the interaction between load and placement, for left hand responses
to the toothbrush, oriented to the left (Triad A).
Figure 19
850
Reaction Time (ms)
800
750
700
650
600
Load
550
No Load
500
450
400
Left
Center
Right
Object Placement
Mean reaction times (ms) for the interaction between load and placement, for right hand
responses to the toothbrush, oriented to the left.
73
Figure 20
850
Reaction Time (ms)
800
750
700
650
600
Above
550
Below
500
450
400
Left
Center
Right
Object Placement
Means reaction times (ms) for the significant effect of placement for the load/no load comparison
in Triad D, as a function of spatial relation (right orientation, right hand response).
74
APPENDIX B: HSRB APPROVAL