Theory of Mind in Individuals with Alzheimer-Type Dementia Profiles

181 Pages·2015·1.2 MB·English

by  Gina L. Youmans

Florida State University Libraries
Electronic Theses, Treatises and Dissertations The Graduate School
2004
Theory of Mind Performance of Individuals
with Alzheimer-Type Dementia Profiles
Gina L. Youmans
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THE FLORIDA STATE UNIVERSITY

COLLEGE OF COMMUNICATION

THEORY OF MIND PERFORMANCE OF INDIVIDUALS
WITH ALZHEIMER-TYPE DEMENTIA PROFILES

By

GINA L. YOUMANS

A Dissertation submitted to the
Department of Communication Disorders
in partial fulfillment of the
requirements for the degree of
Doctor of Philosophy

Degree Awarded:
Summer Semester, 2004

Copyright © 2004
Gina L. Youmans
All Rights Reserved
The members of the Committee approve the dissertation of Gina L. Youmans defended on June
15, 2004.

Michelle S. Bourgeois
Professor Directing Dissertation

Michael E. Rashotte
Outside Committee Member

Howard Goldstein
Committee Member

Leonard L. LaPointe
Committee Member

Approved:

Howard Goldstein, Chair, Department of Communication Disorders

John K. Mayo, Dean, College of Communication

The Office of Graduate Studies has verified and approved the above named committee members.

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TABLE OF CONTENTS

List of Tables …………………………………………………………………………… v
Abstract ………………………………………………………………………....… vii

1. LITERATURE REVIEW …………………………………………………………… 1
Theory of Mind………………………………………………………………….. 1
Theories of Theory of Mind……………………………...……………………… 4
Theory of Mind Assessment………………………………………..…………… 8
Acquired Theory of Mind Impairment in Neurogenic Populations…...………… 12
Summary of Evidence for Theory of Mind Impairment………………………… 29

2. INTRODUCTION …………………………………………………………………… 37

Theory of Mind………………………………………………………………….. 37
Purpose……………………………………………...…………………………… 43

3. METHOD …………………………………………………………………………… 45

Participants …………………………………………………………………… 45
Design …………………………………………………………………………… 54
Experimental Stimuli …………………………………………………………… 54
Procedures …………………………………………………………………… 57
Data Coding and Scoring …………………………………………………… 59
Reliability …………………………………………………………………… 60
Data Analysis …………………………………………………………………… 62

4. RESULTS …………………………………………………………………………… 65

Theory of Mind Impairment in AD Participants………………………………… 65
Error Pattern Analysis for Theory of Mind Testing…...………………………… 67
Error Analysis of ToM Inconclusive Trials……………………………………… 73
Correlations Between Theory of Mind Scores and Neurocognitive Tests…….… 73
Case Summaries of Results for Individual AD Participants……………..…….… 77

5. DISCUSSION …………………………………………………………………… 82

Evidence of Theory of Mind Impairment in AD Participants…………………… 82
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Effect of Memory Support on Theory of Mind Performance ……...…………… 83
Individual Case Analyses…………………………..…………………………… 86
ToM Inconclusive Trials…………………………...…………………………… 89
Coincidence of Cognitive Impairments with Theory of Mind Impairment…...… 89
Conclusions………………………………………...…………………………… 91
Study Limitations and Future Research……..……...…………………………… 92
APPENDIX A. Example Story and Scoring for Initial Reading Screening …………… 95

APPENDIX B. First Order False Belief Scenarios…….……………….……………… 99

APPENDIX C. Second Order False Belief Scenarios.……………….………………… 104

APPENDIX D. D. Scoring Protocols………………………..………………………… 111

APPENDIX E. Individual Case Data for AD Participants………………...…………… 114

APPENDIX F. Human Subjects Approval Letter…….………………………………… 156

APPENDIX G. Informed Consent Form……………………………………………….. 158

REFERENCES …………………………………………………………………… 164

BIOGRAPHICAL SKETCH …………………………………………………………… 172

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LIST OF TABLES

1. AD Participant Characteristics, MMSE Scores and RCF Profiling Scores ..… 50

2. AD Profiles on DRS-2 ……………………………………..…………………… 51

3. Control Group Demographics and Cognitive Test Scores ..………………… 53

4. Inter-rater Reliability for Theory of Mind and Neurocognitive Tests ......……… 63

5. First Order, Second Order, and Combined ToM Trial Scores ……………….… 66

6. Number of ToM Pass, Impairment and Inconclusive Trial Scores ………..… 67

7. Frequency of Referral to Story Text During Supported Condition ….…….… 69

8. Group Total Error Scores, and Group Question-type Specific Error Scores …. 70

9. Individual Total Error Scores on Theory of Mind Testing .……………..…… 72

10. Correlations between ToM scores and neurocognitive test scores ………….. 74

11. Scores of AD participants on neurocognitive instruments ………….......…… 76
12. Scores of AD participants on test of executive functioning …………………... 77
13. Theory of Mind Test Results for AD Participant # 1 ………………...………… 116
14. Neurocognitive Test Scores for AS # 1 …………………………………..……… 117

15. Theory of Mind Test Results for AD Participant # 2 ………………………..… 120

16. Neurocognitive Test Scores for AS # 2 ……………………………………..…… 121

17. Theory of Mind Test Results for AD Participant # 3 ………………………..… 124

18. Neurocognitive Test Scores for AS # 3 ……………………………………..…… 125

19. Theory of Mind Test Results for AD Participant # 4 ………………………… 128
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20. Neurocognitive Test Scores for AS # 4 ………………………………………..… 129

21. Theory of Mind Test Results for AD Participant # 5 ………………………..… 132

22. Neurocognitive Test Scores for AS # 5 …………………………………………… 133

23. Theory of Mind Test Results for AD Participant # 6 …………………………… 136

24. Neurocognitive Test Scores for AS # 6 …………………………………………… 137

25. Theory of Mind Test Results for AD Participant # 7 …………………………… 140

26. Neurocognitive Test Scores for AS # 7 …………………………………………… 141

27. Theory of Mind Test Results for AD Participant # 8 …………………………… 144

28. Neurocognitive Test Scores for AS # 8 …………………………………………… 145

29. Theory of Mind Test Results for AD Participant # 9 …………………………… 148

30. Neurocognitive Test Scores for AS # 9 …………………………………………… 149

31. Theory of Mind Test Results for AD Participant # 10 …………………………… 152

32. Neurocognitive Test Scores for AS # 10 …………………………………………… 153

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ABSTRACT

Theory of Mind (ToM) involves a person’s ability to infer what another person knows,
thus taking his or her perspective. Initial evidence has been presented for a ToM impairment in
individuals with mild to moderate Alzheimer’s disease (AD), however preliminary investigations
have failed to dissociate theory of mind difficulty from impairments in general inferencing,
executive functions, and working memory. Deficits in any of these areas could be sufficient to
explain the apparent ToM impairment in the AD population.
Ten participants with mild to moderate AD profiles completed first order and second
order false belief tasks with and without memory support, and their performances on ToM
testing were compared to the performances of elderly controls. All theory of mind testing was
controlled with memory, comprehension, and general inferencing questions, and AD participants
completed neuropsychological testing to concurrently assess general cognitive functioning,
memory, and executive functioning.
Independent and paired t-tests compared experimental and control group ToM
performances. Correlations assessed relations between ToM and neurocognitve test
performances. Descriptive statistics were calculated, and individual case analyses for
performances of AD participants were presented.
Results indicated that AD participants did not exhibit a specific ToM difficulty as
compared to control participants when support for memory was not provided. However,
significant group differences for specific ToM impairment that appeared to be separable from
comprehension, memory and general inferencing difficulties emerged during ToM testing when
support for memory was provided. On individual case analysis, eight of the ten AD participants
exhibited a mild, specific ToM difficulty. Correlations between ToM performance and
neurocognitive test performances were not significant; however four of the eight AD participants
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who exhibited specific, ToM difficulty also had difficulty with executive function testing. The
results of the current study indicate that individuals with mild to moderate AD may possess an
underlying, mild, specific ToM impairment which becomes apparent during supported memory
testing. Such mild ToM impairment in high to moderate AD individuals must be further
investigated, and possible contributions of executive function impairments to apparent ToM
difficulty further explored before the current results can be confidently generalized to a larger
AD population.

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CHAPTER 1
LITERATURE REVIEW

Theory of Mind

Theory of mind is the ability to represent mental states, such as beliefs, intentions
and desires, and to use these abstract representations to guide and form one’s own actions
and beliefs. Theory of mind allows one to attribute mental states to others: to understand
that other people may hold and act upon beliefs different from one’s own. This
appreciation of alternate perspectives is crucial for successful social interaction and
communication. It underlies the ability to comprehend and predict the behavior of other
people, and to interpret the actions of others as meaningful and intentional (Rowe,
Bullock, Polkey, & Morris, 2001; Wellman & Wolley, 1990).
The view of the human mind as an intentional agent that contains mental states
such as beliefs and desires is not new. Such distinguished historical theorists as
Descartes (1637), Freud (Brook, 1992), and Piaget (1945; 1962) have wrestled with the
genesis and development of this distinction between the mental world of the self and the
mental world of others. However, the conceptualization of this mentalizing ability as a
specific skill, distinct from other cognitive functions, and the term “theory of mind”, have
emerged relatively recently from the fields of philosophy (Dennet, 1978) and psychology
(Premack & Woodruff, 1978).
Theory of Mind Impairment
Because theory of mind is currently conceived of as a specialized skill, it follows
that such a specific skill could be selectively impaired, with marked social-
communicative consequences. Specific impairment of theory of mind has been studied
most extensively in children with autism. Theory of mind impairment has been
implicated as a core deficit in autism, and the social-communicative difficulties indicative
of autism have generally been ascribed to theory of mind impairment. These include
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