UNIVERSITÄT BOCHUM
KOGNITIONS
..
.. . . . .
ETHOLOGIE
44780 Boc
HT
Wolfhart Matthäus
IRONIES OF
EXPERIMENTS WITH
IRONIC PROCESSES
Rum
NR. 50/1997
1
Ironies of experiments with ironic processes
Abstract
In a pilot study we followed the line of Wegner et al. (1993), who combined two
research traditions in their second experiment:
Wegner's longstanding research an the parädoxical effects of mental
suppression,
reaction-time studies of the automatic grabbing of attention by affectively
charged stimuli.
Instead of the emotional Stroop task we used the dotprobe technique to demonstrate
ironic attentional bias towards a suppressed word which, in contrast to Wegner's
materials, was not genuinely affective. In a dotprobe trial the critical word is presented
above or below a neutral one. To the left or the right side of one of the words a dot has
to be detected and registered by a corresponding keypress, as fast as possible. If the
critical word automatically biases attention towards itself, detection of a dot near the
critical word, that is, in the same line, should be faster than of a far dot.
In a sample of 56 Ss we found a significant effect of bias towards the suppressed word.
But several additional derived patterns of the reaction times did not come out as
expected and lead to a major revision of the assumptions:
Pre- and post-attentional effects of suppression have to be differentiated. There are clues
to a time course of different attentional processes which could probably be
differentiated by varying the exposition, times of -the words. Wegner's labeling of effects
as ironic should be confined to a very specific kind of post-attentional effects. The
differentiation cannot be operationalized in a Stroop task, while dotprobe can be
adjusted to this demand. We propose a refined design for comparing a pure suppression
effect with the effects of familiarity after priming, general emotionality as well as
concern-specific emotionality and expert interest of words.
2
Wegner's experiment
The rationale of their experiment was that forbidding the thought of some "white bear"
or "pink elefant" will charge the corresponding stimuli to a degree that they will grab
the attention before the subject can do anything intentionally. To demonstrate the
selection bias Wegner and his co-workers designed a Stroop-type experiment.
Ss were instructed to think of a recent personal success (or failure) that was very
important to them. They had to write some sentences about the event and rate its
importance.
Immediately after this they were asked to write a 5-min stream-of-consciousness report
wider one of two instructions: either to try to stop thinking about the success or failure
or to try to think about it.
In the third Phase of the experiment they had to name the colours of words taken from
three categories: success-related, failure-related, and neutral words. During this Stroop
task they had to maintain the set to think or not to think about the success/failure topic.
Under the suppress condition the colour-naming reactions to the words from the to be
suppressed category tended to slow down a little bit. This was taken as an indication of
Stroop interference, that is, the intrusion of semantic processing into the naming task.
There seemed to be more semantic processing of the target than of the neutral words.
Because this is contrary to the intended control - no semantic processing - Wegner
speaks of an ironic effect of the suppress instruction. The irony is that the forbidden
content, instead of being avoided, grabs the attention.
Wegner' everyday evidence
Wegner (1994 a, b) reports and analyzes a diversity of everyday evidence of ironic
effects in attempts of mental control. Suppression of disturbing thoughts is the most
clearly paradoxical among them. In fact, the self-instruction "I will stop thinking about
the white bear" proposes a paradoxical project, in so far as this meta-thought implies the
object-thought 'white bear'. In concentrating an my project I have to focus the to be
avoided thought. Only afterwards I can try to flee from it by selecting a far-away topic.
But this distraction strategy is •doomed to failure, according to Wegner's theory.
Wegner's theory and Navon's critique
Wegner (1994 b, 37) supposes, that, in addition to the "Operating Process" selecting a
distractor, an effortless unconscious "Monitoring Process" is launched by die decision to
stop thinking of the white bear. This hidden observer undistractably searches "for
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sensations and thoughts that are inconsistent with the achievement of successful
control". As soon as it finds something suspicious it activates the operating process
anew, thus bringing the failure of control to consciousness. Only the conscious decision
to cancel the control project will deactivate the goal-dependent unconscious monitor.
The monitor has to be conceptualized as an unconscious process, for otherwise its
criteria, the white bear to be avoided, "would corrupt the intended control by
definition".
Wegner specifies asymmetries between the conscious and the automatic processes,
which allow him to predict conditions facilitating ironic effects. A particularly clear
example is mood control attempted by the self-instruction "I will not be sad". To realize
this project the operating process has to choose among many competing non-sad targets,
that is, neutral or cheerful distracting thoughts. Because of competition it may be
difficult to become really absorbed by one of the alternatives. In contrast, the hidden
observer has an easy job. Even tiny traces of sadness will signalize failure of the project.
The person will be alarmed that sadness has returned. The effort to become distracted
from it has to start anew. In proposing a "red Volkswagen" as a (somewhat fascinating)
distractor in one of Wegner's experiments the asymmetry and, in consequence, the
ironic "rebound" of the suppressed "white bear" could be reduced (Wells & Matthews
1994, 156).
Wegner applies the general two-process theory to explain ironies from many fields of
mental control. The intentions to relax, to distract from pain, to go to sleep, to remain
calm, to move without showing tremor, to present oneself as sincere, to believe a
message, to stop smoking, to reduce food intake etc. etc. often produce opposite results,
that is, ironies in the terminology of Wegner.
Vulnerability versus resistance to ironic effects is a major topic of Wegner's research.
The aforementioned asymmetry between conscious and unconscious processing is
increased by mental load. Thus stress raises the probability of self-control attempts
resulting in the opposite of the intended effect. Failure of a self-control project induces
additional stress, setting up a vicious positive-feedback loop.
On the other hand, mental self-control can be learned by patiently being trained, as has
been practiced since antiquity and in all cultures. The therapeutical fast lane of
paradoxical intervention seems to be closed to self-control, because in order to pre-empt
the ironic effect by denying my control project I would have to deceive myself - a
double irony with unpredictable outcome. How, for instance, shall I let go my Intention
to sleep, if it is motivated by the prospects of an extraordinary responsible workload?
The trainability of mental control does not fit neatly with Wegner's two-process theory,
because the monitoring process will not be touched and will in any rase find its chance,
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because absorption to a distractor is limited and, consequently, change of topic
unavoidable. In moments of transition the "white bear" will make itself noticed.
Navon (1994 a, b) is skeptical about the failure-doomed two-process design. Instead he
proposes "lay intervention" as a general explanatory construct for paradoxical effects.
Without special trainings we are inapt to control the highly complex systems of usually
automatic mental processes of moving, attending, believing, boing to sleep etc. If we
nevertheless make attempts at control, our lay interventions cannot but produce the
notorious chaos in the complex systems we ourselves are.
But Navon's is a very global omnibus explanation. To specify a training which is
capable to pre-empt a paradox effect presupposes knowledge of the specific mistakes
the lay persons are constantly committing.
Measurement of attentional bias
The Pool of reaction-time instruments for the study of attentional selection bias has been
extended by MacLeod et al. (1986) who invented the dotprobe technique. Variants of
this procedure have been used to study attentional bias to emotionally charged words in
patients with emotional disorders (generalized anxiety, panic, compulsive, depressive,
phobic disorders, posttraumatic stress syndrome; cf. Mathews et al. 1996). Although
this technique has not been as frequently applied as the Stroop technique, it seems to be
as promising. As contrasted to Stroop, it should even be possible to sharpen its
sensitivity to attentional bias by optimizing the visual conditions. Therefore, dotprobe
should replicate at least all the effects of charging stimuli semantically, and especially
an dimensions of self-relevance, which have been found using Stroop, including the
specific effects of personal-trauma related words (Thrasher et al. 1994), expert
vocabulary (Dalgleish 1995), and experimentally suppressed words. It may be hoped
that. dotprobe will allow to ensure pre-attentive capture by self-relevant stimuli, which a
recent Stroop experiment by Thorpe and Salkovskis (1997) has failed to do: Their
spider words induced Stroop interference in spider phobic subjects only when not
masked (alter 16.6 msec), that is, when strategic deployment of attention was possible.
One reason for this suggestion is that dotprobe may be more sensitive to very short and
weak biasing signals capable only to orient attention while not capable of producing a
disturbing kind of arousal. As regards Stroop interference it is not yet clear, to what
degree it is co-produced by postattentional arousal of a distracting concern or even
stress (Wells & Matthews 1994, 70). Dotprobe, however, touches prima facie vigilance,
that is, preattentional filtering, but allows for derived measures indicating interference
by aroused distracting concems.
In fact, dotprobe has been applied in an increasing number of the most recent studies
concerning attentional bias. Bradley et al. 1997, using tachistoscopes, presented
emotional faces, instead of words, with 500 msec duration immediately followed by
probes. With these materials they produced bias against threat stimuli (more expressive
in dysphoric subjects). But they expect to find automatic attraction of attention towards
threatening faces with shorter SOAs, as has been found in two other studies using word
materials.
One additional reference to a dotprobe study is Westra & Kuiper (1997).
The rationale of dotprobe
Two words are presented simultaneously, above and below the fixation point. One of
the words is charged, the other neutral. A small dot appears, either besides one of the
words, randomly placed at the right or at the left side of the word or, alternatively, at the
place of one of the words, replacing it. The vertical position of this dot - upper line or
lower line - has to be detected and registered by a compatible key-press, as fast as
possible. Nothing has to be done with the words. It seems obvious that their processing
is reflex-like, if they are not too far from the fixation mark. How much of the processing
of the presented words is obligatory, how much depends an strategies, is still debated.
In the original experiment the probe replaced a werd, in later versions, as well as our
study, a lateral probe was used. By the way, the original authors ordered their subjects
to read aloud the upper word, making sure consciousness of its representation. This
practice has not been continued, because it would exclude near-threshold expositions.
The expectation is, that attention will be grabbed by the charged word, so that, if the
point mark is near the charged word, it will be responded to more quickly than, in the
average, if both words are neutral. The expense for this facilitation should be excess RT,
if the point is far from the charged ward, because attention will have to be shifted away
from it. Because of this one can define a spreaded measure of attentional bias: the
differente of RTs between fax and near positions relative to a charged word. The sign of
this spreaded measure will discriminate between attraction to and repulsion from the
charged word.
Considerations about the biasing process
The very notion of selection bias by attention grabbing may have to be differentiated.
Mogg et al. (1997) cites assumptions by Posner and colleagues about three separate
subsystems of orienting: attentional shifting, engagement and disengagement. And in
their information processing model of anxiety Beck & Clark (1997) separate automatic
6
initial registration of threat values from successively more strategic processing which
culminates in the appraisal of coping resources, with different possible results, for
instance, avoidance of the threat stimuli. Thus, there is the question of how long the
attention initially grabbed by a charged stimulus remains engaged by it.
Stormack et al. (1995), with a technique quite similar to dotprobe (only one word
exposed in one of two boxes and replaced by the probe appearing either in the same or
in the other box), found evidence for the attention grabbing by affective words even in a
student control group. They are convinced to have shown that "the emotional cues
elicited sustained focused attention, facilitating an engage mechanism of spatial
orienting". But there are inconsistent findings. MacLeod et al.(1986) report the opposite
tendency with danger words: slower detection of the point in the neighbourhood of the
charged word as compared to the fax position. This is interpreted as shift of attention
away from, rather than towards, the unpleasant cue. By the way, the main result of
clinical interest was that in anxiety patients a patten opposite to that of the nonpatient
subjects showed up: attraction to the danger words, which was taken as a symptom of
weakness of defenses.
An explanation of the discrepancy in the results of normal people may be that there is
some attentional dynamic with negatively loaded words, that is, some switch between
attraction and flight. The two experiments differed in that Stormack had the words
spreaded farther and the point marker appear 600 msec after onset of the words, while
MacLeod et al. delayed the replacing probe by 25 msec after the word exposition of 500
msec duration, that is, the probe appeared 525 msec after stimulus onset. If one dares to
interpret the discrepant tendencies from weakly comparable experiments with
nonpatient subjects they would suggest repulsion as the immediate reaction followed by
attraction.
Systematically presenting the probe alter various delays (or SOAs) might expose the
attentional dynamic if there is one. Something an this line has been done by Mogg et al.
(1997) who expected, in normal subjects with high state anxiety, initial vigilance to
threat words, which should be followed by strategical avoidance. They used three SOAs
(identical to word exposure duration): 100, 500 or 1500 msec. There was evidence for a
bias in the initial shift of attention towards the location of the briefly presented threat,
but no evidence for a subsequent avoidance. Instead, the presumably controlled
maintenance of attention was consistently biased towards the threat, too. Of course, the
authors don't want to exclude avoidance strategies in higher levels of anxiety or with
sharper forms of stress.
All these considerations do not touch the deep theoretical question concerning the
personal antecedents of the biasing processes: chronic accessibility of certain contents
versus chronically increased activation of certain Schemata. It appears plausible to admit
both states:
7
chronic accessibility, as the consequence of multiple use, in expertise,
temporally increased activation in consequence of
suppression efforts,
both of them together in emotional disorders.
Considerations concerning method
A weakness of lateral dotprobe is that the procedure produces much noise from visual
parameters. If the dot is too far from the center, if its visibility is low, or if the subjects
do not fixate their gaze very carefully, they will lose time searching the screen, with the
consequence that the initial process of presumably pre-attentive capture cannot be
separated. The original version of dotprobe avoided the first one of these weaknesses, in
that it masks the words alter a short possibly subliminal - presentation interval and
replaces one of the words with the dot probe. Eye movements will be less likely with
this configuration.
Care should be taken that the subjects adjust their gaze to the fixation mark before each
new trial. If the mark changes its form, one could impose an the subjects an additional
detection or identification task concerning the fixation marks.
At 'first glance, a technique introduced by Mathews et al. (1990) appears to be simpler
and more noise-resistant. "They required subjects to discriminate by a button-press
between the words LEFT and RIGHT." In the presence of an emotional distractor, the
location of which was not known in advance, anxious patients' right / left responses
were slowed down (Wells & Matthews 1994, 72). This interference, however, is
ambigous to the same degree as Stroop-interference bias and arousal are confounded
in this arrangement.
I did not yet try the most promising version of dotprobe, namely the replacing dotprobe.
In a cumulative pilot study done by student groups completing their laboratory exercises
we worked with lateral dotprobe. All groups used the identical TURBO PASCAL
program PARADOX displaying the same stimulus list, with lateral dot probes, to all
subjects. Only the priming conditions were different.
8
A pilot study
General consideration
Because we were mainly interested in the robustness of an ironic effect of suppression
on dotprobe detection we allowed for much variation in subject selection and
experimental conditions. Part of the experimenters took the PARADOX software home
and run the experiments on their home PC, inviting acquaintances as subjects. The rest
used laboratory cells and equipment of the Psychological Institute and invited
Psychology students.
Dotprobe
The program PARADOX reads a stimulus file comprising the word pairs, the position
of the probe, and classification symbols for each pair, fixing the near, fax, or neutral
conditions. The first word of each pair is displayed above the fixation mark which is in
the middle of the screen. There are two random generators active: one decides, with
equal probability, about left or right lateralization of the probe, the other selects the
form of the fixation mark from among the ASCII codes. The changes of form should
make the fixation mark more attractive, but we did not enforce fixation by referring an
additional task to the form.
Each new trial is started with the ENTER key, that is, the subjects decide how much
time they need to adjust fixation.
The words remained visible until a response key had been pressed. The dot appeared
with an unnoticeable delay of 10 msec. The response keys were the compatible '' resp.
'+' keys of the number block to the right of the AT keyboard. They had the Labels '1'
resp. 2' (for the corresponding lines) fixed to them.
In agreement with Wegner's finding, that mental control deteriorates with increasing
mental workload, we introduced a short-term-memory secondary task. In advance of the
word pair plus dot a number was presented for 1.5 sec, which was to be silently read
and kept in mind until after the probe detection. After having responded to the probe the
subject reproduced the number. This could be done by entering it on the keyboard, but
after some experience we preferred to have the subject speak the number out aloud.
Registration by the experimenter was used only to control whether the subject had taken
the secondary task seriously enough. In fact we encountered the opposite problem. We
started with the high-load condition of Wegner et al. (1993), namely six-digit numbers,
and had to convince our subjects that the memory task was only an additional load. At
the beginning some subjects told us that they did not recognize the words because of
their preoccupation with the numbers. This does not exclude subthreshold semantic
processing, quite to the contrary, there have been dranaatic interference findings in the
9
Stroop task with unrecognized affective words (presentation interval below 30 msec; cf.
MacLeod & Hagan 1992). But to make the conditions more uniform we then agreed
upon the low-load condition, two-digit numbers. The PARADOX program can be
instructed by the command-line parameter 1 to include the workload condition. In this
case it expects the numbers to be presented as an appendix to the stimulus file.
PARADOX saves a protocol of the stimulus configurations, the expected and observed
responses (including the digits, if they had been entered before hitting the ENTER key
for starting the next trial), as well as the latencies of the-detection responses. In addition,
PARADOX checks for false responses and averages the RTs within the classes of
stimuli. An U-test for the comparison of FAR to NEAR is calculated so that the printout
shows immediately for each experimental person their strength of attentional bias to the
charged words.
Stimulus list
The stimulus list was constructed under many restrictions. It is centered around two
critical words. Only one of them was the suppressed target word for a particular subject,
the other one belonged to the neutral background (or filler) words. We chose as critical
words BERG and HAUS which were not notoriously charged, but could also function
as neutral words, and were concrete enough to be easily charged by imagination and
suppression tasks.
For each of the critical words we chose one associatively related ward: FELS and
DACH, respectively.
The additional filler words were KIND JUNGE AUTO BUS UHR BALL .
These 10 words were combined into 50 pairs. 18 of the pairs contained one of the
critical words combined with one of the neutral words. BERG and HAUS were paired
twice with each other. Consequently, when for half of the subjects BERG was made the
target word, the stimulus list contained 10 pairs with this target word. Half of the target
pairs had the dot near the target. The stimulus list for the HAUS group differed only in
the dass labels for the pairs.
The same principle was followed concerning the associates FELS and DACH,
respectively.
The remaining 30 pairs consisted of only the neutral words. Four of them were left
without a dot probe (No. 8, 14, 27, 41). The subjects knew that there would be catch
trials to be responded to with the '0' key of the right number block.
We exercised a lot of balancing:
The probe had to be placed equally often in the first and the second line;
each of the critical words and its associates had to be equally often above and below the
fixation mark;
10
each word should be used 10 times;
as far as possible the fillers should be equally distributed over the lines and over the
combinations with critical words;
identical words should be spaced as far as possible;
no target pairs should follow a catch trial
Thus we had 5 classes of stimuli within which the RTs had to be averaged: NEUTRAL
TARGET NEAR (TN) TARGET FAR (TF)
ASSOCIATE NEAR (AN) ASSOCIATE FAR (AF)
RTs to catch trials were left out.
Priming
Before suppression the target word had to be focussed for some time by the subject. We
applied different manners of priming: purely semantic, imaginal-semantic, and visual.
In the condition PURELY SEMANTIC the subject was given the task to build sentences
using the target word.
The condition IMAGINAL-SEMANTIC was implemented in several different ways:
a) Free imagination: The subjects were asked to walk through an imagined house (or
climb an imagined mountain) and to fancy or to remember possible experiences. They
were to concentrate an imagined sensual impressions and report about them in an
abridged form.
b)Directed imagination: In addition the subjects were given an evaluative restriction:
encounter a "dream" target versus a "horror" target (house or mountain).
c) Passive imagination: A belletristic description of a mountain resp. a house experience
was read to the subjects.
We were not interested in comparing the efficiencies of these modifications but in
generalizing from a sample of conditions hopefully efficient without exception.
The consideration which lead to VISUAL PRIMING was that maximum compatibility
between the priming and the dotprobe test should give a maximal ironic effect.
Actualizing and suppressing a concept or mental picture does not necessarily activate
the same operations as seeing the label of the concept displayed. If priming means
manipulating the label there should be more negative transfer from suppression to the
dotprobe task.
The subjects of the VISUAL group were handed a sheet covered with only the target
word printed in a great variety of fonts. They had to inspect the printed specimen of -the
target word and to mark the three most pleasant as well as the three most unpleasant
fonts.
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Since visual priming is a new condition in the context of suppression experiments the
comparison VISUAL / SEMANTIC was of theoretical interest.
Suppression
After completing the priming task all experimental persons received the same
suppression instruction in written form. It suggested a sporting challenge: To attempt
some intriguing kind of self-control. Its full text may be important to evaluate the
method. Therefore I give a translation:
"From now you are required not to think of the word
'house' ('mountain') any more. Please, make a decision
to push away the word like a disturbing thought and to
keep it suppressed. Maintain the suppression also
during the following computer task. In this part of
the experiment you will again see two words, one
below the other, and sometimes a dot to the side of one
of them. Don't be embarrassed if the suppressed word
occasionally is displayed. Try to ignore it. If,
nevertheless, your attention is grabbed by this
word, we shall notice that in your behaviour and
reaction times. So, try not to be influenced by the
critical ward - keep it suppressed."
Subjetts
The Pool of 56 experimental persons was heterogeneous: mostly acquaintances of the
experimenters, of different ages and professions. A minority of the subjects were
second-semester psychology students fulfilling their obligations to participate in
experiments.
12
5. Dotprobe task
6. Replication of Bf-S
7. Post-experimental inquiry about how the subjects
succeeded in their suppression attempts, what they
experienced when confronted with the forbidden word,
whether some of the apparently neutral words had
personal meaning to them
8. Debriefing regarding the expected ironic effects;
obligation not to tell potential experimental persons.
Design
Taking SEMANTIC versus VISUAL priming as one interindividual factor and FAR
versus NEAR position of dot relative to target word as one intraindividual factor we got
a mixed 2 x 2 design. The Bf-S correlates will play a minor role in the following,
because we did not take care to construct a stress and nervousness asale, but selected, by
face validity, only a few items for screening. There is no interest in stimulus-specific
findings, therefore we shall Pool the data from both target words.
The dependent variable with highest priority is the RT from target pairs. The secondary
one is the RT from the associate pairs (DACH if HOUSE was suppressed, FELS if
BERG was suppressed).
Hypotheses
Our primary hypothesis was established within the frame of Bias considerations. It
concerned the existente of an ironic suppression effect produced by attention grabbing
regardless of stimuli and priming conditions. It is about the intraindividual comparison
of the RTs from the five FAR and the five NEAR dots. We labeled 'TF' the average RT
of the detection of dots far from the target word and 'TN' the average RT of the
detection of dots near the target word.
For each subject the expectation was
TF > TN
PARADOX shows the U-test for each individual: the rank order of F and N scores and
the corresponding U-value. <= 4 are the values with p <=0.05, one-sided. From the
observed U and the orderliness of the F, N pattem one can read immediately the
strength of the expected attention-grabbing effect of the suppressed word in the
individual case.
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To evaluate the hypothesis
mean TF > mean TN
on the basis of our Sample we counted the significant Gases ; subjected the TF-TN
difference scores to a one-sample t-test against HO = 0, and calculated a sign test on the
numbers of positive versus negative differentes TF-TN
The hypothesis of secondary interest concerning the associate of the target word, AF >
AN , was analogous, except that significance was not tested in the individual case.
Still lower hypotheses regarded comparisons with the average RT of NEUTRAL pairs.
The prediction was that, in comparison to this unbiased reference condition, attentional
bias should be facilitative with NEAR dots and expensive with FAR dots. This
motivated the compound hypothesis
TF > NEUTR > TN
and its less demanding part hypothesis
TF > NEUTR ,
both of them, in fact, only tested with regard to the means.
The comparison of RTs to thematically and neutrally embedded probes may receive
high theoretical priority, if one changes the theoretical frame, which predicts
preattentional bias, and takes two additional models into consideration:
•
I would like to follow an idea of two of our student experimenters (Hasan Irmak
and Alexandra Schallau), to the effect that a word pair containing a charged word could
raise vigilance without bias and thus lower RT in coinparison to a word pair containing
only neutral words. I would like to call this a kind of atmosphere effect of the mixed
word pair. According to this hypothesis, its first impression as a whole would be like:
"There it is once again", without even an exact localization of the source (critical word).
•
Still not without plausibility is the assumption of arousal of a distracting
concern, or even a bit of stress, elicited by the awareness of failure of suppression. This
appears particularly plausible in the frame of a self-focussing interpretation (cf. Wells &
Matthews 1994, 197 ff) of the suppression task.
Drawing together the different lines of theoretical considerations, we get three
competing models of ironic suppression effects:
•
Bias. which could be towards the charged word (TF>TN)
or against the charged word (TF<TN),
Vigilante, indicated by insignificant TF-TN-differences
and speeded RTs with charged pairs (TN,TF < NEUTR),
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Arousal, predicting insignificant TF-TN-differences
and a slowing down with charged pairs (TN,TF > NEUTR).
As regards the intergroup comparison VISUAL versus SEMANTIC our commitment to
the prevalence of visual priming was not strong. We were content to count the positive
and negative TF-TN differences in both groups.
Concerning the level of nervousness / stress (as indicated by BfS questions) we had
two expectations: Pre-dotprobe stress should increase the likelihood of ironic failure of
suppression, while failure of suppression should further increase the level of stress.
Thus, we expected to find positive correlations between TF-TN and pre-dotprobe level
of stress as well as between TF-TN and the difference between pre- and post-dotprobe
levels.
Results and discussion
The primary hypothesis "TF > TN" was significantly validated in only 5 of the 56 cases
(U <= 4). Thus, there appeared to be only restricted generality of a clearly ironic effect
under the conditions of our study.
Yet there was a noticeable prevalence of positive differences: 40 against 15 (in one case
the difference was exactly zero). This ratio was highly significant according to onesided one-sample t-test and sign test. The mean difference TF-TN was 38 msec, the
range 300 to -214 msec.
The hypothesis "TF > NEUTR > TN" was invalidated by the majority of cases (38). Not
much better was the loosened hypothesis
"TF > NEUTR" - 33 cases against. That means, there is a prevalence of cases in which
both, reactions to TF as well as to TN, were slower than to the neutral pairs. This is
what the Vigilance hypothesis predicts.
The existence of an attentional bias following suppression is undeniable, but the ironic
selection of the forbidden is not necessary. In 15 cases the reverse bias prevailed repulsion from instead of attraction to die forbidden. Some of these reversals might
even be significant instances for the reversed hypothesis.
What is worse, we cannot be quite sure, even in the 5 cases with individually significant
bias towards the suppressed word, that this is the effect of suppression alone. Three of
die student experimenters (Regina Becking, Beate Drawe, Sabine Imberg) ingeniously
noticed that the priming might have been sufficient for the critical word to grab
attention. As was the case in the Stroop experiment of Wegner et al. (1993) we had not
avoided confoundation of priming and suppression.
15
On the other hand, familiarity after priming does not explain the non-negligeable
number of cases biased from the critical word (repulsion).
Both directions of the attentional bias are densely masked by relatively high variability
of the RTs within the same dass as compared to the variability between the classes.
Some of this variability, especially the reversal of bias, may be caused by idiosyncratic
reactions to the nominally neutral words. This explanation is suggested by the
unexpectedly high averages of neutral RTs, as well as by comments of subjects. Most of
the reversal cases (TN>TF) are combined with high RTs in neutral pairs:
NEUTR>TN>TF. According to postexperimental interviews, KIND or JUNGE have not
been neutral words to mothers. Thus, the attentional bias from the ironic effect of
experimental suppression is partially masked by an attentional bias from
preexperimental personal concerns. These may be of various types: affective meanings
as well as expertise.
The hypothesis conceming the associate of the target word - "AF > AN" - was not
supported. Two thirds of the cases showed the reversed pattern. This suggests that there
was not even the tendency to spread the ironic effect to the associate. There was a
noticeable asymmetry between the frequencies of the four combinations of target with
associate'patterns: Half of the cases showed one of the patterns, namely: ironic tendency
with the target (TF>TN) and the reversal with its associate (AF<AN). The prevalence of
this pattern was a little bit more expressive in the semantic than in the visual priming
conditions. If one takes only the cases with a direct ironic influence of the target, the
proportion of reversals with the associate is 11 from 18 in the visual and 16 from 22 in
the semantic conditions. The pattem "irony with target and reversal with associate"
seems to be compatible with the abovementioned hypothesis of an attentional dynamic:
If one assumes repulsion from the target to be the earliest reaction followed by
attraction, -dien there should be some phase shift with associates as compared to the
target ' activation of the target representation from the associated stimulus needs some
additional time. But this remains a highly speculative explanation.
Now to the intergroup comparison of the priming conditions. Among the 19 cases with
visual priming there was only one case with a definitely reversed effect (TF-TN=-214),
whereas among the 37 semantic cases there were 14 with reversed effect. The average
speed superiority of NEAR dots compared to FAR dots in the 18 positive cases of the
visual condition was 80 msec. as compared to 90 msec in the 22 positive cases of the
semantic conditions. Our expectation that the suppression of visually primed words is 2
least as effective in irony production as the suppression of semantically primed words
was supported.
16
None of our level-of-stress scores (from BfS adjectives) did correlate with TF-TN. The
coefficients for pre-dotprobe, post-dotprobe and the post-pre-difference were almost
exactly zero, so that we would not expect to fmd significant relationships by expanding
the number of items.
General discussion
The ironic attention grabbing by suppressed words could not be established as a reliable
general phenomenon under the conditions of our study. This is an irony for the
experimenters who expected to use a better method than Wegner but got worse results.
But let's see whether our irony cannot - ironically be reversed by expanding the
theoretical frame. Apart from weaknesses of the dotprobe instrument, which might be
eliminated by optimizing response training and dot visibility, there is much variability
of responding which could not all be accounted for by idiosyncratic concerns touched
by some of the nominally neutral words, but has to be taken seriously.
There seem to be different types of handling the return of the suppressed:
Subjects who noticed the unwanted word and felt disturbed should have lost time
coping with this intrusion. Since their attention has been shifted inwards for some time
before they are able to search for the dot, the TF-TN difference should be scattered only
at random around zero, and both target RTs should be higher than the neutral RT. For
these individuals the suppression situation might be interpreted as one of self-awareness
induction and the repeated confrontations with the to-be-suppressed target as so many
reinforcements of self-focussing. If this hypothesis should materialize, Wegner's twoprocess theory will be in need of a minor revision: The monitoring process might be
raised to the conscious level - with the consequence that the person will be temporarily
confused by a self-defeating effort. Else, in Navon's terms one could say, these are the
individuals suffering from lay intervention. In these subjects I would assume realization
of the distracting-concern-arousal model.
The ironic biasing effects on RT should be restricted to individuals who reported that
they did not recognize the words. Within them there might be types differing in the
efficiency of their defenses, the most efficient being repelled from the "dangerous" sign
and, consequently, showing the reversal of the ironic effect. Unfortunately, one cannot
test this hypothesis on the RTs, because they are confounded with semantic charges on
the nominally neutral words. Else one would expect that the reversals (TN>TF) were
combined with slow reactions as compared to neutral pairs (TN>TF>NEUTR).
That the opposite tendency prevails (TN>TF are in most cases below NEUTR) is
consistent with the Vigilance model.
Daring a positive interpretation of the conflicting data I would propose to differentiate
two levels of ironic effects of suppresssion:
17
the automatically effective remnants of the suppressed
content, which could activate Vigilante and / or
processes,
the irony of suppression on the level of self-awareness,
eliciting disturbing Arousal.
The first case can be subsumed under the category of priming. 1 would prefer not to call
it an ironic effect at all, because suppression has been efficient to the level of quasirepression. In fact, the suppressed content manifests itself outside of awareness, through
unnoticed filtering and orienting the attention towards or against the critical content.
Wegner's monitoring process has not even time to report anything.
The second case is ironic also from the perspective of the subject herself. This is what,
on the arousal interpretation, can be measured by Stroop interference.
Our differentiation of suppression effects might give a partial explanation of the missing
correlations between stress scores and biasing score (TF-TN). High levels of stress
would raine the risk of conscious suppression failure, and the resulting arousal might
increase distress even further. Since these hypothetical connections concern postattentional processes, our expectation to find correlations with pre-attentional biasing
(as measured by TF-TN) was erroneous from the beginning.
One methodological conclusion will be the re-evaluation of dotprobe compared to
Stroop technique. For the measurement of the ironic effects of suppression dotprobe
seems, at first glance to be less adequate at least in cases of self-focussing. But the
pattern "awareness of self-focussing and RT-means corresponding to the formula
TF=TN>NEUTR" should indicate second-level suppression effects, that is, ironic
effects proper.
Now the ironical reversal of our irony (to get worse than better results than Wegner) is
equivalent to a meta-irony: We were going to suppress thought about the dotprobe
method which gave us worse results than Stroop did to Wegner, and had to confront
return of the suppressed: What appeared to be a weakness of the method (sensitivity to a
blas which was not there) turns out as its strength (the derivability of measures
operationalizing the other models, too). And on this meta-level, once again we find a
reversal of the irony: Instead of failing to suppress (a recalcitrant methodological
notion) we get a successful redescription of the dotprobe situation. What we
thoughtlessly defined as an ironic effect (pre-attentional biasing manifested in TF>TN)
is not ironic at all, while the real ironic effect lies hidden where we thought we had only
experimental noise (TF,TN > Neutr)
18
Prospects
A future experiment applying the replacing-dotprobe should be designed to discriminate
the aftereffects of suppression on the two hypothetical levels. To achieve this it must
take into account the following considerations and try to provide some relevant
information about the following points:
•
We have to find out the best mode of fixation. This might
be the usual locking at the mark at the screen, but
far-adapted "meditative" looking through the screen to
infinity, producing the impression of a double mark.
not
•
While some of our subjects produced a nearly
thoroughgoing Ironie biasing reaction to suppression
("ironic" in the original undifferentiated sense of
significant U-tests), another part of our sämple showed
nearly perfect "repulsion from the suppressed". The
discrepancy may depend on individual differences in the
efficiency of mental control. Thus the experimenter ought
to check:
How good is the individual in mental control, especially
avoidance of unwanted representations? Experts of
Autogenic Training ought to be singled out.
In addition, the middle group with chaotic TF-TN
differences are interesting candidates for the hypothesis
of self-focussing under suppression demands, irony
proper. There is need of a correlate reflecting this
tendency.
•
Since there have been found different dimensions capable
of attention grabbing the stimulus materials have to be
specified with regard to these dimensions.
Which of the occurrences of the target word have been
paired with idiosyncratically charged fillers? The
PARADOX software (in its new version PARADOKS) allows for
re-analysis of a protocol alter re-classification of the
pairs. Thus the TF-TN comparison can be based on
instances without semantic competition. The most pure
separation of suppression from semantic effects would,
of course, be warranted by replicating the experiment
with. ASCII symbols as stimuli. A still better control
19
might be to pair each word with an anagram of itself.
Thus the Biasing, Vigilating, or Concern-arousing forces
of the suppressed words could be compared with Chose of
decidedly neutral, of frequently used, of emotionally
charged, and of self-relevant words.
There should be systematic variation of SOAs (from word
to probe exposition), in or der to map a potential
attentional dynamic. SOAs shorter than 100 msec (the
shortest one realized by Mogg et al. 1997) ought to be
included, to check the generality of Thorpe & Salkovskis
(1997) finding (no bias with masking after 16.6 msec).
Analysis should stress the interaction of SOAs with
degrees of self-relevance, to investigate the degrees of
processing achieved at different intervals. For there are
suggestions that semantic specificity needs more
processing than anoverall affective evaluation: The
general as contrasted to the concern-specific affective
value of a stimulus seems to be detected pre-attentively
(Mathews & MacLeod 1994; McNally 1995). But definitely to
establish the range of purely automatic semantic
activation is an extremely difficult tack, as has been
argued by Holender (1986). Still under the impression of
these arguments Cowan (1995, 11) proposes to adopt an
indeterminate stance.
To evaluate how easy it is to train suppression in these
conditions the series should be replicated several times
(each time repeating the suppression instruction).
In order to separate the contributions to bias of familiarity
and of suppression we need two critical words for each
session. While both of them have to be visually primed
in parallel, only one of them has to be suppressed.
In an ideal experiment, it would be possible to estimate the profiles of the relative
weights of each of the three models (Arousal, Vigilance, Bias) under each of the four
semantic conditions (Neutral, Expertise, Global Affect, Specific Concern) through a
series of processing stages.
20
Appendix
I would like to include some excerpts from the documentation of the TURBO PASCAL
software PARADOKS. Starting the program one can read the full information after
entering a '?'.
PARADOKS evolved from a program used by Aleksandra Gruszka in Cracow to study
negative priming with letters. It was adapted for graphics mode and stimulus generation
from a pre-fixed file. Its original aim has been supplanted by several other types of
experiments which can be selected by command-line parameters on startup. The most
recent development has been the dotprobe paradigma.
The actual revision called PARADOKS is the result of a lot of insights from the pilot
study.
The stimulus file to be written in ASCII muss have a specific layout:
Each line specifies one trial. The two words and the classifying symbols have reserved
places (column numbers). The Erst word will be shown above the second word. Up to
five categories of thematically significant words can be mixed in the file. The number
specifying the category of the thematic word in a given trial (1 through five) has to be
placed at column 31. One of these categories might be nominally neutral words, others
might be generally affective and individually affective words. The neutral partner of -the
thematic word in each trial should be defmitely neutral (for instance, an anagram of the
other word or a function word). In column 32 the program expects to find one of the
letters f and n (signifying the trial as „dot far from the thematic word" or „dot near to
the thematic ward", resp.). The program will sort and average the reaction times
according to the code 1f 1n 2f 2n , and for each of the five categories it will
present an U-test comparing far and near trials.
Column 38 contains one of the digits 1 or 2 determining the placement of the dot
(above or below the midpoint, resp.). Für catch trials, 0 is used to suppress the dot.
Column 35 fixes the expected reaction key (in the pilot study columns 38 and 35 were
identical. The program translated the rightmost keys
and '+' into '1' and '2',
respectively).
An experiment with variable short exposition times of the words, with masking, and
with replacement of one of the words by the dot standing alone on the screen (that is,
without a midpoint marker) has to be started by the following command line:
paradoks w ds- i .
The parameters have the following meanings:
w present words
ds- present dot in place of masked word, suppress midpoint marker
i
variation from trial to trial of exposition time and dot delay after masking.
Parameter i induces PARADOKS to read the timing values (in msec) from the file, that
is, PARADOKS expects to find as many lines with two numbers each as there are trials.
21
The stimulus block and the timing block have to be separated by one line, which might
be empty or contain a comment.
Trials an which the subject responds too quickly or to slowly will be repeated once, at
the end of the series. The criteria kritu and krito , resp., are preset and can be changed
in the source code (at present: 250 and 1500 msec, resp.).
PARADOKS writes a a protocol to the actual directory. It requires a labet composed of
„code of series" and „number of session" from the experimenter and adds the extension
*.dat.
PARADOKS can be started with parameter p to read and analyse a protocol from an
experiment. This parameter has to be combined with the parameters describing the
experiment which has generated the protocol. The option is useful, if the experimental
subject has scaled the words alter the experiment and the experimenter wants to reclassify the trials and the corresponding reaction times accordingly. How to edit the reclassified protocol for the re-analysis by PARADOKS is explained in the selfdescription PARADOKS gives an
22
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Berichte aus der Fakultät für Psychologie
der Ruhr-Universität Bochum
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Arbeitseinheit Kognitions- und Umweltpsychologie
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II
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Physische und psychische Wirkungen von Umweltgiften
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III
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Zur Funktionalität der „Vertikalen-Täuschung" (41/1993)
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Psychische Auswirkungen von Umweltbelastungen (42/1993)
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Bedroht durch Luft, Wasser und Nahrung? (43/1994)
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Zwischenbericht
„Sortieren geht über Studieren" - Durchführung und Evaluation
einer psychologischen Intervention zur Förderung der Müllfraktinierung in einer Universitätscafeteria (48/1996)
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IV