A STUDY IN OVERLEARNING WITH HUMAN SUBJECTS
James H. Popham
Submitted to the Faculty of Graduate Studies and Research
in partial fulfillment of the requirements for the degree
of
Master of Science
MoGill University
Montreal
1951
AOKNOOŒDGMENTS
I am indebted to Dr. W. N. Kellogg :for his lecture
course at Indiana University in which he suggested
the possibility that overlearning might account :for
same apparently contradictory resulta in learning
exper~ents.
The present exper~ent grew out of an
elaboration of his suggestions.
The apparatus used in this experiment was built to
my specifications by Mr. Jospeh Labrecque of the
Canadian Broadcasting Corporation.
INDEX.
ACKNOWLEDGMENTS ••••••••••••••••••••••••••••• Page 2
THE NATURE OF THE PROBLEM ••••••••••••••••••••
4
EXPERIMENTAL :PROCEDURE ••••••••••••••••••••••
9
.................................
Procedure ................................
Apparatus
9
r·-,
9
.....................................
13
...................
15
SID.[LWY •••••••••••••••••••••••••• • • • •• • • • • • •
19
.................................
21
RESULTS
DISCUSSION A11D CONCLUSION
BIBLIOGRAPHY
"[.,'!
-4-
THE NATURE OF THE PROBLEM
The present experiment is an attempt to show how conditions
that lead to a fixated response may account for soma cantradictory
resulta in learning experimenta.
More specifically. it will be shown
that overlearning fixates a response in terms of its kinestheticmotor pattern so that a fixated response will not readily give way to
more appropriate behavior under experimental conditions that require
a change in the kinesthetic-motor response.
In general, maze learning experimenta do not uphold a proprioceptive theory of learning.
The·majority of experimenta favor a
cognitive theory although the evidence is by no means unequivocal.
Dashiell's (4) open-alley multiple choice maze in which the rat follows
no fixed path to the goal contraindicates a movement hypothesis in
learning as does the field orientation exper±ment with rats of Hebb
(6), the cortical destruction experimenta of Lashley and Ball (10),
the water versus land maze of Macfarlane (11), and the tracing experimenta with humans of McGeoch (12).
The supposedly crucial experiment
of lengthening or shortening maze segments after learning has given
contradictory resulta.
Carr and Watson (2) reported interference with
both equal and differentiai lengthening and shortening, Hunter (8)
found no effect with either, Honzik found that equal shortening of
the segments disturbed behavior but that equal lengthening did not,
Kohler 1 maintains equal lengthening or shortening should not affect
performance as the maze retains its "Gestà.lt" properties but that
1 Reported by Hunter (8) as persona! communication.
- 5 -
differentia! lengthening or shortening should interfere with performance
as the "Gestalt" properties of the maze are lost.
Carr_ in a later
experiment (1)~ argues that the introduction of new stimuli or a greater
range of stimuli disrupts behavior but that the removal of stimuli does
not.
Although in his experiment the lengths of the segments is not one
of the variables, it is evident that lengthening the segments increases
the amount of stimulation and therefore performance level should drop
but shortening the segments should not affect performance as the amount
of stimulation is decreased.
In the experimenta where a change in the required movement
did not result in a drop in performance
leval~
or where the drop per-
sisted for the first few trials only,.the resulta are taken to support
a cognitive theory of learning_ but where performance is significantly
interfered with by a variable requiring a different motor response
the resulta are taken to support a motor theory of learning.
degree of rapprochement might be effected by the use of
criptive concepts "docile" ,and "fixated" ( 13).
response
Some
To~an's
des-
Thus where the learned
gives way rapidly to other behavior, should the latter be more
appropriate, the learned response is said to be "docile".
Similarly
"fixated" is used for a learned response that does not give way rapidly
to another more appropriate response when the experimental conditions
are changed.
An experimental situation where the response is docile
would be taken to support a cognitive theory of learning, and one where
the response is fixated would be cited in support of a proprioceptive
theory of learning.
The experimental conditions that give rise to either docile
- 6-
or fixated behavior have received little experimental investigation.
An understanding of these conditions would, however, reconcile many of
the contradictory resulta already mentioned.
They would be reconciled
much in the manner that the continuity-noncontinuity controversy has
been partially resolved, at least in its experimental aspects, by recourse to the experimental conditions, whether the discrimination is
difficult or easy, whether the discriminanda are central or high in the
field of vision, whether the trials are massed or distributed, whether
the motivation is strong or weak, and whether the subjects are naive
or sophisticated.
"Fixated11 and
11
docile 11 are comparative terms, and, rigorous-
ly, an experiment should be performed under both conditions with our
present knowledge of their effects in order to adjudge their relative
contribution to the resulta.
A response that appears fixated may,
under changed experimental conditions, be comparatively docile.
Similarly, a fixated respamse may be given a spurious
appearanc~
of
dooility by virtue of the experimental conditions.
One of the sufficient conditions to establish a fixated
responae is excess frequency.
Krechevsky and Honzik (9) trained rats
to varying degrees of excess frequency on the longer path of a maze in
which the shorter was blocked.
On removal of the block the rapidity
of shift to the shorter path was approximately inversely proportional
to the degree of overlearning.
It is important to note that Krechevsky
and Honzik only claim that excess frequency is one sufficient condition
for fixation.
Hebb (6) shows that excess frequency does not necessarily
result in fixation.
In the experimenta so far ci ted, any change in the experimental
situation has required a new response, and behavior termed fixated or
docile depending on the rapidity with which the new respQnse supplanta
the old.
Under conditions where a new response is not required, but
the same response remains adaptive to the changed experimental conditions, we know little about the affects of fixation or docility of a
response.
From Krechevsky and Honzik it can be inferred that what is
fixated is a pattern of movements, a kinesthetic-motor pattern, and so
predicted that a change in the experimental situation which does not.
require a change in the kinesthetic-motor response pattern should not
interfere with performance when the response is fixated.
Under such
conditions a fixated response would have a false appearance of
docility.
It can be further inferred from Krechevsky and Honzik that
when a new response is required interference with performance will be
greater after the old response is fixated than before.
Accepting their
evidence that excess frequency is a sufficient condition for fixation,
the following theory is proposed.
Learning that requires a motor response is docile in its
early stages.
Performance involves the whole situation and any change
in that situation w211 interfere with the response.
After overlearning
theresponseis fixated in terms of the kinesthetic-motor pattern and
only a change in the experimental situation that requires a change in
that pattern will interfere with performance.
Where a change in motor
response is required a fixated response will be more greatly interfered
with than a docile response.
In the following experiment, based on this theory, human
subjects were set the task of learning a checkerboard maze where the
correct path was tapped out with a stylus, a light indicating a correct
- 8 -
square and a buzzer a wrong square.
After the maze was learned to a
predeter.mined criterion of learning various modifications were
introduced, some requiring a change of motor
response~
some not.
subjects then overlearned the unmodified pattern, after which the
same modifications were re-introduced •
•
The
- 9-
EXPERIMENTAL PROCEDURE
Apparatus
A checkerboard maze of ten by ten rows of li inch square
brass plates placed i inch apart on a 21 by 21 by 1 inch board
painted black was used.
The brass squares were glued to the board
and a lead soldered to their backs which lead through a drilled hole
to the back of the board.
A metal unit containing a flashlight bulb
and a buzzer was attached centrally at the top of the board.
The
pattern was made by connecting in series with flexible copper wire
the leads of the appropriate squares. the wire then lead through the
light to a six volt battery.
nected in series through the
battery.
All other squares were similarly con~uzzer
to the same terminal of the
A metal stylus on a three foot cord·'.soldered to the other
terminal of the battery completed the circuit.
The stylus was about
the size of a pencil 1 it had a metal tip and an insulated grip.
The
board was inclined at an angle of 30 degrees trom perpendioular by
means of two legs which were invisible from the front.
See Figure
1.
Procedure
After a short preliminary test on two subjects. a thirtysquare pattern was judged too diffioult for the purposes of the
experiment and a pattern of twenty-one squares within a checkerboard of eight by eight squares was used.
The outside square of
plates was masked wi th brown paper.
Only one of the brass plates in the bottom row was attaohed
- 10 -
Figure 1
Schamatic Diagram of Apparatus
(Basic Unmodified Fattern Shown)
·-·-·!-l=l=----·-·-·- i
r··-~=::l---:·-·-·-·
ci-:=:-r~:-!
~
---+--'
: : Z:=;
.
"
- 11 -
to the light circuit, this constituted the starting point.
one square in the top row was the goal.
Similarly,
The nineteen intermediate
and consecutive connections formed a pattern of straight !ines and
right angles.
There were no diagonals.
connected to the buzzer circuit.
All other brass plates were
The basic unmodified pattern is
shawn in Figure 1.
The five subjects used were collage students between the ages
of nineteen and twenty-seven.
They were given the following instruc-
tions.
"In front of you is what is called a checlœrboard maze.
correct path
thro~gh
The
the maze will be shown by the white light.
Every time you touch the right square with the stylus the white
light will go on and you will know that you are on the right
path.
Every time you touch a wrong square you will hear a
buzzer and know that you are on the wrong path and must try
another square.
You can move only one square at a time and
only in a horizontal or vertical direction, not diagonally
(demonstrated).
Find the correct square
in the bottan row,
there is only one, and then the series of intermediate squares
that is the correct path as indicated by the light to the last
square of the pattern which is in the top raw.
Do you under-
stand?"
Following are the details of the experimental procedure.
Time per
trial was recorded with a stop watch and pne error counted for each
sound of the buzzer.
Part 1.
The maze was learned to a criterion of ten·consecutively
correct trials.
The following modifications were then
- 12 introduced one at a
t~e
for ten trials each except where noted
with five trials on the unmodified pattern between eaoh.
a.
The light indioating the correct path was disoonnected
for ten trials.
..
The subjeots were told that there would
be no light indicating the correct path.
All ten trials
are included in the results.
b.
The subjects were instruoted to follew the maze fran
"goal" to "start". All ten trials are inoluded in the
resulta.
o.
The sub jects performed the maze wearing a thick winter
glove. All trials are inoluded in the results.
d.
The whole pattern was shifted one place to the right so
that the form of the pattern remained intact but its
relation to the rest of the checkerboard was changed.
The subjects were told the pattern had been changed and
one unrecorded trial was given before the ten test trials.
e.
An entirely new pattern of twenty-one squares was learned
to a criterion of ten conseoutively correct trials.
Part 2.
Two hundred overlearning trials were given on the unmodified
pattern.
Part 3.
T~e
was recorded for the last ten trials only.
Following the overlearning trials Part 1 a. to e. inclusive
was repeated exoept that a third new pattern of twenty-one
squares was substituted for 1 e. and learned to a criterion
of ten consecutively correct trials.
- 13 -
RESULTS
In all cases the error score dropped quickly to zero therefore time in seconds will be the only measure of performan ce reported.
The results are summarized in Tables 1 1 2 1 3 1 4, and 5.
Table 1
Averagè Time in Seconds per Last Ten Trials and Grand Mean
for Five Subjects Before and After Overlearn ing the Maze.
1
2
3
4
5
Mean
Before Overlearning
6.0
4.2
4.8
5.4
5.0
5.1
Atter Overlearning
4.4
3.7
4.0
4.2
3.8
4.0
Subject
,.
Table 2
Average Time in Seconds for Ten Trials and Grand Mean for
Five Subjects Under Four Condition s Before Overlearn ing
Subject
Condition
1
2
3
4
5
No Light
6.8
5.4
5.6
6.2
6.0
6.0
Reverse
6.0
6.1
5.6
6.0
5.4
5.8
Glove
5.6
4.6
s.o
5.4
5.2
5.2
Shi tt
7.5
6.6
6.8
7.0
6.6
6.9
Mean
- 14Table 3
Average Time in Seconds for Ten Trials and Grand Mean for
Five Subjects Under Four Conditions After Overlearning
Subject
Condition
-
~-
-~
~---
1
--
2
3
4
5
Mean
1---
No Light
4.4
3.7
4.0
4.2
3.8
4.0
Reverse
6.7
7.8
6.5
6.8
5.8
6.7
Glove
5.3
5.8
5.4
5.8
5.4
5.6
Shift
5.8
5.2
5.0
5.2
4.8
5.2
Table 4
Numerioa1 and per cent Increase of the Grand Means Before
and After Overlearning Under the Four Conditions
Condition
Before Overlearning
(0 = 5.1)
Per Cent
Inorease
Increase
After Over1earning
(0 = 4.0)
Per -rren~
Increase Increase
No Light
0.9
17.6
o.o
o.o
Reverse
0.7
13.7
2.7
67.5
Glove
o.
1.9
1.6
40.0
Shift
1.8
35.3
1.2
30.0
Table 5
Average Time in Seconds for First Ten Trials and Grand Mean
for Five Subjects to Learn a New Pattern Before and After
Overlearning the Basic Pattern
Subject
1
2
Before Overlearning
20.3
lUter Over1earning
15.9
3
4
5
Mean
10.8
15.6
18.4
14.4
15.9
7.5
11.4
11.8
8.2
10.6
1
- 15 -
DISCUSSION AND CONCLUSIONS
On the baeis of the theory it would be predicted that before
overlearning all four conditions (Tables 2 and 4) would result in a
drop in performance level from the preceding ten (criterion) trials
(Table 1).
Af'ter overlearning however (Tables 3 and 4) 1 only those
conditions that require a change in the kinesthetic-motor response
pattern should show a drop in performance leval from the last ten overlearning trials (Table 1), that is, the "reverse" and nglove" trials.
Further, there should be a greater interference with performance after
overlearning than before in the "reverse", "glove", and in the "new
pattern" (Table 5) trials.
With one exception the resulta in Tables 2, 3, and 4, are
in conformity with the theoretical predictions.
The variant results
concerna performance when the pattern is shifted so that its relationship in the stimulus situation is changed but not the form of the
pattern.
The resulta in Table 5 are directly contradictory to the
theoretioal predictions.
After overlearning (Tables 3 and 4) the eue value of the
light dropped to zero, there being no interference with performance,
whereas before overlearning (Tables 2 and 4) removal of the light from
the stimulus situation resulted in a drop in performance leve!.
This
is in conformity with the theoretical prediction that the pre-overlearning response is docile and affected by any change in the stimulus
situation but that excess frequency fixates a kinesthetic-motor
response which is not disturbed by changes in the stimulus situation
that do not require an adaptive motor response.
A false appearance
- 16-
·of docility is given to the overlearned response and of fixation to
the pre-overlearning response if the results are viewed without reference to the experimental conditions.
In the "reverse" trials, where the stimulus situation remains
unchanged but the required response is different, interference is
greater after overlearning than before (Tables 2, 3, and 4).
It is
not immediately clear that this result supports the contention that
what is fixated is a kinesthetic-motor response, but it does damonstrate
in a different situation than Krechevsky and Honzik's (9) that excess
frequency will fixate a response.
In the Krechevsky and Honzik exper-
iment fixation was demonstrated by a change in the stimulus situation,
the stimulus situation in the present experiment is unchanged in the
"reverse" trials.
It might be expected that practice affects operate
against these resulta, but even so, fixation by excess frequency is
dominant.
The change of kinesthetic eues in the "glove" trials resulted
in only a slight and probably insignificant interference before overlearning (Tables 2 and 4), but after overlearning (Tables 3 and 4)
interference is marked and supports the contention that excess frequency
fixates a kinesthetic-motor response.
The glove permitted the subjects
to retain the s ame relative positioning of their fingers as without it,
the affects of kinesthetic eues might be better shawn, particularly
before overlearning, by a change in the stylus which would change both
kinesthetic eues and finger position.
Where the pattern is shifted it was predicted that there
would be no interference with performance after overlearning as the
- 17-
kinesthetic-motor response is unchanged by the change in relationship.
There is. however, considerable interference with performance after
overlearning (Tables 3 and 4).
There are two possible explanations
for this. If it can be argued that a change in relationship ipso facto
involves a change in response, then it is incorrect to state that the
response is unchanged when the pattern is shifted.
In which case it
would be expected that performance after overlearning would be disrupted;
however, it would also be expected that such disruption would be of a
larger magnitude after excess frequency and consequent fixation of the
response than before.
As this is not the case. the more likely explana-
tion is that the kinesthetic-motor response is fixated more specifically
to the stimulus situation than has b een assumed 1 and a change of relationship in the stimulus situation is sufficient to interfere with a fixated
response even though the motor response is unchanged.
The possible
affects of practice make these resulta and their interpretation equivocal.
It is possible that practice acted to lower the magnitude of
interference after overlearning, in which case the first explanation is
the more likely.
Had the pattern been shifted to the left after. oveF-
learning instead of to the right. the resulta would be less ambiguous.
It is to be concluded l'rom Table 5 that, contrary to the
predicted result 1 excess frequency and consequent fixation on one pattern
does not interfere with the learning of another. in fact learning is
initially aided.
In all cases the average for the first ten trials of
the new pattern is lower after overlearning than before.
The best
explanation of this probably lies in the verbal report of the subjects
that as the experimental sessions progressed they got the "feel" of
what to do and how to do it.
The phenomenon is likely similar ta
- 18 Harlaw's monkeys (5) "learning-to-learn", and suggest to the writer
that naive subjects are not necessarily desirable.
In view of these
results the procedure would probably be tmproved by the inclusion of
several pre-experimental patterns to acquaint the subjects more
thoroughly with the type of situation.
It must be concluded from the
present resulta however, that for naive subjects overlearning on one
task leads to more rapid initial learning on another task campared
with initial learning on a similar task before overlearning.
It is not, in any instance, assumed that the response is
identical in its
kinesthetic~otor
components from trial to trial,
only that there is a gross similarity between responses that become
more fixated with repetition.
It is to be doubted that there is ever
an exact repetition from one trial to another of the same movements
(Cook, 3), a possible and special exception to this being muscle action
potentials in the foreperiod of reaction time experiments 2 •
Observa-
tion of the subjects in the present experiment allowed the presence of
oniy gross similarities to be concluded.
2
•
Unpublished resulta repcrted by Dr. R.
course at Indiana University •
c.
Davis during a lecture
- 19 SUMMARY
We have assumed that an overlearned response is a fixated
response - a response unadaptable to changed
exper~ental
conditions,
and attempted to show that this fixation is of the kinesthetic-motor
response pattern.
The results of the "light",
the "reverse" trials support the theory.
11
glove", and possibly
The "shirt" and "new pattern"
variables are contradictory to the theory.
The results of the "new pattern" trials are likely due to
the experimental procedure and should be quite easily controlled by
the suggested
pre-exper~ental
trials.
Even so, the fixated response
need not be of a kinesthetic-motor pattern to obtain the predicted
results, it need be only a response 'unadaptable to changed experimental conditions' without further specification.
The
11
shift" results
are not readily explained and more work is required to clarify the
affects of a change in relationship after fixation of the response.
The uncontrolled effects of practice make any alternative explanation
doubtful.
In both the "light" and
11
glove 11 trials the pattern itself
remained unchanged, in the former the removal of the visual eue was
effective to interfere with the docile response but not the fixated,
in the latter the changed kinesthetic eues interfered with the fixated
response to a marked extent but not with the docile response.
The
"reverse" trials do not necessarily support the requirement that a
motor response is fixated, only that a response is fixated, but
they do give further support to Krechevsky and Ronzik (9) in a
different situation.
- 20 -
In spite of the ambiguity of some of the results it is obvious
that performance will be radically different depending on whether the
response is docile or fixated.
In this experiment it has been assum.ed
that the response was fixated after overlearning and by overlearning,
and that it was docile before overlearning.
It is probable that there
are other conditions that will fixate a response earlier in the learning process, these supposedly extraneous factors will make the interpretation of the resulta difficult and contradictory in a way analogous
to the continuity-noncontinuity results.
- 21 -
BIBLIOGRAI'HY
J. anim. Behav., 1917
1.
Carr, H. A.
2.
Carr, H. A., and Watson, J. B. Orientation in the White Rat•
1._· comp. Neurol. and Psychol., 1908, 18, 27-44.
3.
Cook, T. W.
Repetition and Learning. I. Stimulus and Response.
Psychol. Rev., 1944, 51, 25-36.
4.
Dashiell, J. F.
Direction Orientation in Maze Running by the
White Rat. Comp. Psycho1. Monogr., 1930, 7, No.32.
5.
Harlow, H. F.
The Formation of Learning Sets.
1949, 56, 51-65.
6.
Hebb, D.
7.
Honzik, C. H.
The Role of Stimulation in Maze Learning:
Specificity và. Patterning. J. comp. Psychol.,
1939, 27, 149-164.
-
8.
Hunter, W. S.
A Further Consideration of the Sensory Control of
the Maze Habit in the White Rat. J. genet. Psychol.,
1930, 38, 3-19.
9.
Kreohevsky, I. and Honzik, C. H. Fixation in the Rat• Univ.
Calif. Publ. Psycho1., 1932, 6, 13-26.--
10.
Maze Studies with White Rats.
7, 259-275.
o.
Lashley, K.
Studies of the Organization of Behavior. 1.
Behavior of the Rat in a Field Orientation.
!· canp. Psychol., 1938, 25, 333-354.
s., and Ball, J. Spinal Conduction and Kinesthetio
Sensitivity in the Maze Habit.
1929, 9, 71-106.
11.
· 12.
13.
Psycho1. Rev.,
J. comp. Psyohol.,
Macfarlane, D. A. The Role of Kinesthesie in Maze Learning.
Univ. Calif. ~· Psychol., 1930, 4, 277-305.
McGeoch, J. A.
The Psycho1ogy of Human Learning. New York:
Longmans, Green and Co., 1946. Pp.xvii - 633.
Tolm.an, E. C. Purposive Behavior in Animals and Men. New Yorkt
The Century Company, 1932. Pp. xiv - 463.