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C:\Documents and Settings\lproctor\Local Settings\Temporary Internet Files\OLK8\Copyright - thesis (2).doc The Psychology of Suggestion and Heightened Suggestibility Balaganesh Gandhi Thesis submitted for the degree of Doctor of Philosophy Department of Psychology University College London l UMI Number: U592822 All rights reserved INFORMATION TO ALL USERS The quality of this reproduction is dependent upon the quality of the copy submitted. In the unlikely event that the author did not send a complete manuscript and there are missing pages, these will be noted. Also, if material had to be removed, a note will indicate the deletion. Dissertation Publishing UMI U592822 Published by ProQuest LLC 2013. Copyright in the Dissertation held by the Author. Microform Edition © ProQuest LLC. All rights reserved. This work is protected against unauthorized copying under Title 17, United States Code. ProQuest LLC 789 East Eisenhower Parkway P.O. Box 1346 Ann Arbor, Ml 48106-1346 Abstract Hypnosis is associated with profound changes in conscious thought, experience and behaviour and has a long clinical and experimental history. Data on the nature and role of hypnotic induction procedures is still somewhat lacking however, and probably the only thing one can say about them with any conviction is that they enhance suggestibility in some cases. Nevertheless, a review and re-analyses of previous work reveals that the effect of the induction of hypnosis on suggestibility may be substantial, comparable to psychological treatments in general. The work reported here makes a clear distinction between the hypothetical ‘hypnotic state’ and the phenomena produced by suggestion and aimed to investigate the necessity for the former in producing suggestibility changes and the mechanisms by which both exert their influence. As it had important implications for how non-hypnotic and hypnotic suggestibility were measured in the thesis, Study 1 (n=312) examined the relationship between lateral asymmetry and bodily response to suggestion. Study 2 (n=102) and Study 3 (n=105) explored the notion that absorption and reduced critical thought are instrumental in how inductions effect responses to test-suggestions and suggestions for pain modulation respectively. Study 4 (n=105) investigated the effect on suggestibility of a hypnotic induction and the extent to which the magnitude of this effect is altered by labelling the procedure ‘hypnosis’. Study 5 (n=105) examined the influence of compliance to requests on suggestibility and addressed the role of strategy selection in response to suggestions. The findings are important for both clinical and experimental applications and indicate that important determinants of subsequent responses to suggestion are: (i) the definition of the situation as hypnotic which in turn enhances the expectation of benefits; (ii) the focussing of attention and the reduction of critical thought; and (iii) the facilitation of engaging in goal-directed behaviours through compliance to requests. 2 Acknowledgements First of all I would like to express my sincere gratitude to my supervisor Professor David Oakley for his generosity, kind encouragement and expertise. His humility, energy and dedication will always serve as a model for me. Also many thanks to Mat and Alex for their friendship and support. I am especially grateful to all my friends for putting up with me through this. I will not list you here, as I no doubt will leave some of you out and find myself apologising to many at a later date. Anyway, you know who you are. I am forever indebted to my parents who taught me the importance of truth, patience and indomitable will. I thank them for all the opportunities they have given me and for whatever knowledge I have acquired. Finally, I owe thanks above all to my dearest Viv, without whom I would have nothing. Thank you for patiently and lovingly looking after me and contributing greatly to whatever lucidity and cohesiveness is found here. 3 Contents Abstract Acknowledgements Contents List of Tables List of Figures Chapter 1 - Suggestion and Suggestibility 1.1. The nature of suggestion and suggestibility 1.2. Suggestibility independent of hypnosis 1.3. Suggestion and suggestibility within the domain of hypnosis 1.4. Hypnotic suggestibility and social influence 1.5. Hypnotic suggestibility and the placebo response 1.6. Hypnotic suggestibility and interrogative suggestibility 1.7. Measuring ‘hypnotic’ suggestibility 1.7.1. The Stanford Scales 1.7.2. The Barber Suggestibility Scale 1.7.3. The Creative Imagination Scale 1.7.4. The Carleton University Responsiveness to Suggestion Scale 1.7.5. The Hypnotic Induction Profile 1.8. What are ‘hypnosis’ scales measuring: hypnotizability vs. suggestibility? 1.8.1. Hypnotic and non-hypnotic suggestibility revisited 1.8.2. More limitations 1.9. Conclusions Chapter 2 - The State of ‘Hypnosis’ 41 2.1. Defining hypnosis 41 2.1.1. Two principle theoretical perspectives 42 2.1.2. Trance and altered states vs. experiences produced by suggestion 44 2.2. I f ‘hypnosis’ is a state, what kind is it? 47 2.2.1. Hypnosis as a non-state 47 2.2.2. Hypnosis as a state of relaxation 55 2.2.3. Hypnosis as a state of absorption 56 2.2.4. Hypnosis as a state of dissociation 60 2.2.5. Hypnosis as an altered state of brain functional organisation 68 2.3. Conclusions 73 Chapter 3 - Hypnosis and Suggestibility 77 3.1. Hypnosis and suggestion 77 3.2. Early experiments involving a single test of suggestibility 78 3.3. Experiments involving standardised test-suggestions 80 3.3.1. Limitations 82 3.3.2. Braffman & Kirsch (1999) 84 3.3.3. The ‘true’ effect of hypnotic inductions 87 3.3.4. Group administered vs. individually administered 88 3.4 General conclusions and outline of empirical chapters 89 Chapter 4 - Study 1: Is There a Lateral Asymmetry in Bodily Response to Suggestion? 93 4.1. Introduction 93 4.1.1. Hypnosis as a right-hemisphere function 94 4.1.2. Hypnosis as a sequence of left followed by right hemisphere function 95 4.1.3. Parallels between conversion disorder symptoms and suggested effects 97 4.1.4. Lateralisation of conversion disorder symptoms 98 4.1.5. Lateralisation of responses to ‘hypnotic’ suggestions 99 5 4.1.6. Study objectives 100 4.2. Method 102 4.2.1. Participants 102 4.2.2. Measures 102 4.2.2.1. Responsiveness to suggestion 102 4.2.2.2. Handedness questionnaire 103 4.2.3. Design and procedure 104 4.3. Results 104 4.3.1. Arm levitation sample 104 4.3.2. Arm immobility sample 106 4.3.3. ‘Classic suggestion effect’ 107 4.4. Discussion 108 4.4.1. ‘Suggestive’ approach vs. use of ‘hypnotic’ procedures 109 4.4.2. Implications for conversion disorder 110 4.4.3. Conclusions 111 Chapter 5 - Study 2: Effects of Absorption and Reduced Critical Thought on Responses to Suggestion 112 5.1. Introduction 112 5.1.1. How do hypnotic inductions facilitate responses to suggestion? 113 5.1.1.1. The experiential-phenomenological approach 113 5.1.1.2. Summary 116 5.1.2. Absorption 117 5.1.3. Reduced critical thought 118 5.1.4. The effects of instructions for absorption and reduced critical thought 120 5.1.4. Study objectives 121 5.2. Method 122 5.2.1. Design 122 5.2.2. Measures 124 6 5.2.2.1. Suggestibility scale 124 5.2.2.2. Absorption and critical thought 126 5.2.3. Hypnotic context and inductions 126 5.2.4. Participants 127 5.2.5. Procedure 128 5.2.6. Statistical analyses 129 5.3. Results 129 5.3.1. Effect of condition on suggestibility 130 5.3.2. Absorption, critical thought and relaxation 133 5.3.3. Manipulation check 136 5.4. Discussion 136 5.4.1. The hypnotic context and suggestibility 137 5.4.2. The role of state changes in determining increases in suggestibility 138 5.4.3. Have state changes occurred? 139 5.4.4. The use of strategies 142 5.4.5.