Alexithymia, Stroop interference, and verbal abilities

186 Pages·2005·3.12 MB·English

by  Cole, Gordon.

Alexithymia, Stroop Interference, and Verbal Abilities:
Sex differences
Gordon C. Cole
B.A. (Honours), The University of Ottawa, 1982
M.A., Simon Fraser University, 1984
THESIS SUBMITTED IN PARTIAL FULFILLMENT OF
THE REQUIREMENTS FOR THE DEGREE OF
DOCTOR OF PHILOSOPHY
Psychology
O Gordon C. Cole 1991
SIMON FRASER UNIVERSITY
May 1991
All rights reserved. This work may not be
reproduced in whole or in part, by photocopy
or other means, without permission of the author.
APPROVAL
Name: Gordon Campbell Cole
Degree: Doctor of Philosophy
Title of Thesis: Alexithymia, Stroop Interference,
Verbal Abilities: Sex Differences
Examining Committ ee:
Chair: Dr. William Krane
Dr. Paul Bakan
Senior Supervisor
Dr. Robert Ley'
D .: Ray ~o$rnah
Dr. Christopher Davis
Internal Examiner
Dr. Robert Pihl
External Examiner
McGill University
a
Date Approved:
PARTIAL COPYRIGHT LICENSE
I hereby grant to Simon Fraser University the right to lend
my thesis, project or extended essay (the t i t l e of which is shown below)
to users of the Simon Fraser University Library, and to make partial or
single copies only for such users or in response to a request from the
library of any other university, or other educational institution, on
its own behalf or for one of its users. I further agree that permission
for multiple copying of this work for scholarly purposes may be granted
by me or the Dean of Graduate Studies. It is understood that copying
or publication of this work for financial gain shall not be allowed
without my written permission.
Title of Thesis/Project/Extended Essay
Alexithymia, Stroop Interference, and Verbal A b i l i t i e s :
Sex Di f ferences
Author:
is ignature)
Gordon C. Cole
(name)
Mav 6, 1991
(date)
Alexithymia (a term meaning no words for feelings) is a hypothetical
construct representing a constellation of cognitive-affective characteristics
observed in people with a wide range of psychological and physical
disorders, and in people who derive little benefit from insight oriented
psychotherapy. Two general questions about alexithymia were addressed in
this thesis: "Do alexithymics have a 'deficit' of feeling? Do vocabulary or
word fluency deficiencies account for the alexithymic's expressive
difficulties?". An emotional Stroop task was constructed to measure the
cognitive representation of emotion, while verbal abilities were measured
with the Vocabulary and Similarities WAIS-R subtests, and a verbal fluency
test. There were three main findings. (1) Males with high alexithymia
scores exhibited greater interference on neutral, as well as positive and
negative emotion Stroop stimuli, suggesting a Stroop effect for males with
high alexithymia scores, regardless of emotional valence. Verbal fluency
was found to be a factor contributing variance to the relationship between
alexithymia and Stroop scores for males. (2) Females with high alexithymia
scores had lower vocabulary and emotional vocabulary scores than females
with low alexithymia scores. No significant differences in vocabulary
scores were obtained between the male alexithymia groups, and there were
no significant differences in word fluency or abstract reasoning between
both male and female alexithyrnia groups. (3) Sex differences in color
i i i
naming ability were observed. Males were generally slower than females at
color naming. For females color naming scores were significantly correlated
with alexithymia scores (while insignificant among males, these
relationships were of similar smngth and direction). Slowed color naming
may be included in the constellation of characteristics associated with
alexithymia. Overall, the results of this thesis may be interpreted as
suggesting that the affective difficulties of alexithyrnics may be secondary to
cognitive difficolties. There also seems to be a sexual dimorphism in
cognitive correlates of alexithymia. Similarities between alexithymia and
neuropsychological syndromes, perceptual styles, and sex differences in
cognitive abilities and hemispheric lateralization provide some theoretical
support for this interpretation of the results.
Acknowledgements
I wish to thank Paul Bakan for believing in me, challenging my limits, and for tolerating
my wanderings from the path. Bob Ley has been a consistent source of inspiration in all
areas of becoming a clinical psychologist. Ray Koopman has endured my statistical alogia
with grace, and I thank him for his help in examining and analyzing a challenging data set.
Chris Davis has been another challenging representation for me from beginning to end. I
wish to thank Robert Pihl for being my external examiner and for providing me with a new
window on the cognitive correlates of alexithyrnia. I also wish to acknowledge the
contribution and support of Paul Sungalia who was instrumental in the design of the
emotional Stroop test and was a true collegue in all senses. I thank Jim Marcia for
providing the ideal location for the incubation of the final stages of the thesis. I thank Joan
Foster for her patient assistance with the data crunching. Finally, I wish to thank my
parents for their consistent support and understanding.
Table of Contents
...
.............................................................................................
Abstract rn
...............................................................................
Acknowledgements v
......................................................................................
List of Tables ix
...
.....................................................................................
List of Figures xm
. ..............................................................................
I INTRODUCTION 1
............................................................
Measurement of Alexithymia 4
. Etiological Explanations ................................................................. 9
.................................
Hemispheric Specialization and Alexithymia 10
Cognitive Representation. Information Processing.
.....................................................
and Subliminal Perception 20
..................................................................
The Stroop Test 24
..............................................................................
Hypotheses 3 3
. .......................................................................................
I1 METHOD 35
....................................................................................
Subjects 35
...............................................................................
Procedures -37
..................................................................................
Measures 38
.....................................................
The Emotional Stroop Test 38
................................................
The Toronto Alexithymia Scale 46
....................................
The Vocabulary subscale of the WAIS-R 50
............................................
An emotional vocabulary subscale 51
......................................
The Similarities subtest of the WAIS-R 51
........................
The controlled oral word ~ssociation(F AS) ~ e s;t 51
. .....................................................................................
I11 RESULTS 53
.....................................................
Emotional Stroop and Alexithymia 61
......................................
Repeated Measures of Stroop Variables 61
..........................................
Neutral emotion Sump interference 64
..........................................
Positive emotion Stroop interference 67
........................................
Negative emotion St roop interference 6 9
...............
Word fluency and Sump: controlling the effects of fluency 71
..................................
Age. alexithymia. and Stroop interference: 75
..............................................
Controlling for the effects of age 75
..........................................
Controlling for both age and fluency 79
......................................................
Alexithymia and Verbal Measures 81
.........................................................
Emotional Vocabulary 8 3
............................... .'.......... ......
Word Fluency and Alexithymia 86
...................................................
Similarities and Alexithymia 87
................................................
Color Naming and Alexithymia 90
....................................................
Fluency and Color Naming 92
.........................................................
Age and Color Naming 93
. ................................................................................
IV DISCUSSION 95
.....................................................
Emotional Stroop and Alexithymia 96
......................................
Sex Differences in Sump Performance 101
...........................
Sex Differences in Color Discrimination Abilities 104
..............
Sex Differences in Perceptual Speed and Cognitive Abilities 104
.........................
Sex Differences in Lateralization of Brain Function 105
......................................
Implications for Psychosomatic Theory 109
.....................
Similarity of alexithyrnia to neurological "syndromes" 111
Vocabulary and Alexithymia ............................................................ 120
............................................................
Similarities and Alexithymia 124
...............................................
Verbal Fluency and Alexithymia 124
............................................
Sex Differences in Verbal Abilities 125
...........................................
Sexual Dimorphism of Alexithymia 126
.........................................................
Color Naming and Alexithymia 126
.................................................................................
Conclusion 135
....................................................................................
REFERENCES 138
.....................................................................................
APPENDICES 156
......................................................
Summary Statistics All Ss 160
..........................................
Female Summary Statistics (n=124) 160
........................................
Male Summary Statistics (n=54) 160
viii
st of Tables
. .........................................................
TABLE 1 Neutral Word Parameters 40
. .......................................................
TABLE 2 Negative Word Parameters 41
. ........................................................
TABLE 3 Positive Word Parameters 41
. ......................................................
TABLE 4 Neutral Words Color Count 42
. .....................................................
TABLE 5 Positive Words Color Count 43
. ......................................................
TABLE 6 Negative Word Color Count 44
. . ..................................
TABLE 7 Sample characteristics of Taylor et al (1985) 47
. .........................................
TABLE 8 Sample characteristics of present study 48
. ........................................
TABLE 9 Correlation Matrix All Subjects (n=178) 58
. ...................................
TABLE 10 Correlation Matrix Female Subjects (n=124) 59
TABLE 11. Correlation Matrix for Males (n=54) ............................................6 0
. ............
TABLE 12 All Ss Repeated Measures: Cell Means and Standard Deviations 62
. .......................
TABLE 13 All Ss Repeated Measures: Stroop Interference Scores 62
. ...........
TABLE 14 Females: Alexithymia by Stroop Interference Repeated Measures 63
. ................
TABLE 15 Male Alexithyrnia by Stroop Interference Repeated Measures 64
.
TABLE 16 All Ss: Mean neutral S w pi nterference scores as a function of
................................................................
alexithymia and sex 65
.
TABLE 17 Male Ss: Mean neutral Stroop interference scores as a function of
........................................................................
alexithyrnia -66
.
TABLE 18 Female Ss: Mean neutral Stroop interference scores as a function
......................................................................
of alexithymia 67
.
TABLE 19 All Ss: Mean positive Stroop interference scores as a function of
...................................... ... .........................
alexithymia and sex 67
.
TABLE 20 Male Ss: Mean positive Stroop interference scores as a function of
........................................................................
alexithymia -68