Neuropsychological Consequences of Experimentally-Induced Anxiety on Working Memory ...

193 Pages·2016·4.33 MB·English

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University of Southampton
Faculty of Social, Human and Mathematical Sciences
School of Psychology

Neuropsychological Consequences of
Experimentally-Induced Anxiety on Working Memory
Performance

by
Warren Neil Dunger
BSc MSc MBPsS

Thesis for the degree of
Doctor of Clinical Psychology

May 2016
Word Count: 19898
II
UNIVERSITY OF SOUTHAMPTON
ABSTRACT
FACULTY OF SOCIAL, HUMAN AND MATHEMATICAL SCIENCES
School of Psychology
Thesis for the degree of Doctor of Clinical Psychology
NEUROPSYCHOLOGICAL CONSEQUENCES OF EXPERIMENTALLY-INDUCED
ANXIETY ON WORKING MEMORY PERFORMANCE
By Warren Neil Dunger
Many theories addressing the complex anxiety-cognition interaction are built upon the
notion that working memory is vulnerable to the effects of anxiety. However, most
research has utilised studies of trait anxiety which does not allow direct inferences to be
made between affect and cognitive performance, or exclude confounds such as pre-
existing individual differences. As a result, a systematic review was undertaken to explore
the neuropsychological consequences of experimentally-induced state anxiety on working
memory. Twenty eight studies were included in the review grouped according to the nature
of anxiety induced (anxious-apprehension or anxious-arousal) and by working memory
component (verbal, visuospatial, or executive). This review found evidence of anxiety
adversely affecting working memory and support for specific theories. The review
highlighted the potential impact of anxiety on neuropsychological assessments in clinical
settings, as well as the need to test these theories using prolonged anxiety-induction
procedures with standardised measures of anxiety and working memory.
The empirical paper explored the effects of experimentally-induced anxiety on
clinical neuropsychological assessments of working memory. Anxiety was induced using the
inhalation of carbon dioxide (CO ), which reliably elicits prolonged states of anxiety. Thirty
2
participants were included in the study, undertaking neuropsychological tests during the
inhalation of both normal air and CO across two testing sessions using a counterbalanced
2
design. The mood manipulation was successful and verified using psychological and
physiological measures. Results suggested that anxiety negatively affected spatial and
verbal working memory, although low load verbal tasks were unaffected. Clinical
implications of these findings are discussed with regards to the effect of state anxiety on
clinical neuropsychological assessments and the management of anxiety in light of these
cognitive deficits. Future research should include a broader spectrum of working memory
tasks of varying cognitive load to further elucidate how anxiety may interact with cognition.

III
IV
Table of Contents
Page
ABSTRACT III
Table of Contents V
List of Tables XIII
List of Figures XV
Declaration of Authorship XVII
Acknowledgements XIX
Abbreviations XXI
Chapter 1: Systematic Literature Review 1
1.1 Introduction 1
1.1.1 Anxiety 2
1.1.1.1 Evolutionary Origin of Anxiety 2
1.1.1.2 Defining Anxiety 2
1.1.1.3 Neurocognitive Mechanisms of Anxiety 2
1.1.2 Working Memory 3
1.1.2.1 Origins of Working Memory 3
1.1.2.2 Defining Working Memory 4
1.1.2.3 Neurocognitive Mechanisms of Working Memory 5
1.1.3 Psychological Theories of Anxiety and Working Memory 6
1.1.3.1 Processing Efficiency Theory 6
1.1.3.2 Attentional Control Theory 6
1.1.3.3 Hemispheric Asymmetry Hypothesis 7
1.1.3.4 Two-Component Theory of Anxiety 7
1.1.4 Aim of the Review 8
1.2 Method 9
1.2.1 Search Strategy 9
1.2.2 Inclusion and Exclusion Criteria 9
1.3 Results 11
1.3.1 Descriptive Characteristics of Studies 11
V
Page
1.3.2 Methodological Considerations 12
1.3.3 Psychological and Physiological Measures of Anxiety 20
1.3.3.1 Psychological Measures 20
1.3.3.2 Physiological Measures 21
1.3.3.3 Methodological Considerations 21
1.3.4 Neuropsychological Measures of Working Memory 22
1.3.4.1 Verbal Working Memory Measures 23
1.3.4.2 Visuospatial Working Memory Measures 24
1.3.4.3 Central Executive Measures 24
1.3.4.4 Methodological Considerations 24
1.3.5 Anxiety-Induction Procedures 25
1.3.5.1 Anxious-Apprehension Induction Procedures 25
1.3.5.2 Anxious-Arousal Induction Procedures 26
1.3.5.3 Methodological Considerations 26
1.3.6 Anxiety and Working Memory Performance 27
1.3.6.1 Verbal Working Memory Performance 28
1.3.6.1.1 Anxious-Apprehension 28
1.3.6.1.2 Anxious-Arousal 28
1.3.6.2 Visuospatial Working Memory Performance 28
1.3.6.2.1 Anxious-Apprehension 28
1.3.6.2.2 Anxious-Arousal 28
1.3.6.3 Central Executive Performance 29
1.3.6.3.1 Anxious-Apprehension 29
1.3.6.3.2 Anxious-Arousal 29
1.3.6.4 Methodological Considerations 29
1.3.7 Mediating and Moderating Factors 32
1.3.7.1 Self-Control 32
1.3.7.2 Task-Irrelevant Thoughts 32
1.3.7.3 Verbal and Imagery-Based Worry 32
1.3.7.4 Salivary Cortisol 33
VI
Page
1.3.7.5 Cognitive Load 34
1.3.7.6 Mental Effort 34
1.3.8 Neurocognitive Mechanisms 35
1.4 Discussion 37
1.4.1 Summary of Findings 37
1.4.2 Overview of Methodological Considerations 38
1.4.3 Clinical Implications 39
1.4.3.1 Classification of Anxiety Disorders 39
1.4.3.2 Management of Anxiety 40
1.4.3.3 Neuropsychological Assessment 40
1.4.4 Recommendations for Future Research 41
1.4.5 Limitations of the Review 41
1.4.6 Conclusion 42
Chapter 2: Empirical Paper 43
2.1 Introduction 43
2.1.1 Anxiety 44
2.1.2 Working Memory 44
2.1.3 Psychological Theories of Anxiety and Working Memory 45
2.1.4 Anxiety and Clinical Neuropsychological Assessments 46
2.1.5 Carbon Dioxide Experimental Model of Anxiety 47
2.1.6 Mediating and Moderating Factors 48
2.1.7 The Present Study 48
2.1.8 Hypotheses 49
2.2 Method 51
2.2.1 Design 51
2.2.2 Participants 51
2.2.3 Measures 52
2.2.3.1 Neuropsychological Assessments 52
2.2.3.1.1 Digit Span 52
2.2.3.1.2 Spatial Span 52
VII
Page
2.2.3.1.3 Trail-Making 53
2.2.3.2 Questionnaires 53
2.2.3.2.1 State-Trait Anxiety Inventory 53
2.2.3.2.2 Penn State Worry Questionnaire 54
2.2.3.2.3 Generalised Anxiety Disorder-7 54
2.2.3.2.4 Brief Fear of Negative Evaluation Questionnaire 54
2.2.3.2.5 Verbalizer-Visualizer Questionnaire 54
2.2.3.2.6 Cognitive Interference Questionnaire 55
2.2.3.2.7 Cognitive Interference Questionnaire - Imagery 55
2.2.3.2.8 Rating Scale for Mental Effort 55
2.2.3.2.9 Qualitative Feedback 56
2.2.3.3 Physiological Measures 56
2.2.4 Apparatus 56
2.2.5 Procedure 56
2.2.6 Ethics 58
2.2.7 Data Preparation and Analysis 58
2.3 Results 61
2.3.1 Descriptive Statistics 61
2.3.2 Mood Manipulation Check 63
2.3.3 Main Analysis 67
2.3.3.1 Anxiety x Working Memory Performance 67
2.3.3.1.1 Spatial Working Memory 67
2.3.3.1.2 Verbal Working Memory 68
2.3.3.1.3 Central Executive 69
2.3.3.2 Anxiety x Mental Effort 70
2.3.3.2.1 Mental Effort for Spatial Working Memory 70
2.3.3.2.2 Mental Effort for Verbal Working Memory 70
2.3.3.2.3 Mental Effort for Central Executive 70
2.3.3.3 Anxiety x Processing Efficiency 70
2.3.3.3.1 Spatial Working Memory and Efficiency 72
VIII
Page
2.3.3.3.2 Verbal Working Memory and Efficiency 72
2.3.3.4 Anxiety x Working memory Capacity 72
2.3.3.4.1 Spatial Working Memory Capacity 73
2.3.3.4.2 Verbal Working Memory Capacity 73
2.3.4 Supplementary Analyses 73
2.3.4.1 Trait Anxiety 73
2.3.4.2 Worry 74
2.3.4.3 Fear of Negative Evaluation 74
2.3.4.4 Cognitive Interference 74
2.4 Discussion 75
2.4.1 Summary of Findings 75
2.4.2 Clinical Implications 78
2.4.2.1 Clinical Neuropsychological Assessments 78
2.4.2.2 Interventions for Anxiety 80
2.4.3 Methodological Limitations 81
2.4.4 Future Research 81
2.4.5 Conclusion 82
Appendices 83
Appendix A – Search Terms and Databases 83
Appendix B - Graphs and Figures for Literature Review 84
Appendix B.1 Global Distribution of Studies 84
Appendix B.2 Participant Characteristics 84
Appendix B.3 Mean Age of Participants for Each Study 85
Appendix B.4 reported Sample Size for Each Study 85
Appendix B.5 Histogram for the Frequency of Sample Sizes 86
Appendix B.6 Published Papers Included in the Review by Year 86
Appendix C – Frequency of Working memory Measures 87
Appendix D – Summary of Anxiety-Induction Procedures 88
Appendix E – Sample Size Calculations 89
Appendix F – Telephone Pre-Screening Interview 90
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