Implicit Emotional Memory and the Effects of Positive Suggestion during Colonoscopy
thesisposted on 18.11.2011, 11:06 by Andrew Scott William Sheen
Introduction - This research aimed to investigate implicit emotional memory and the effects of positive suggestion during colonoscopy with conscious sedation. Evidence of emotional arousal in response to a word stimulus, without conscious recall, was investigated Method - During colonoscopy, under midazolam sedation and fentanyl analgesia, participants (N=25) heard either positive suggestion or nursery rhyme titles. Measures of mood, intra-operative distress, post-traumatic stress traits and sleep disturbance of the two groups, were compared throughout three time periods. Sedative effect on emotional memory formation was examined pre and post-procedurally, using the Skin Conductance Response (SCR) technique to compare participants' physiological reactions to nonsense-words, two emotive and one neutral. Procedural-based questionnaires and mood measures were completed one hour and two days after colonoscopy. Results - There was a significant difference between distress levels in suggestion-groups with the positive suggestion group demonstrating less intra-operative distress. There was no significant effect of what participants heard under sedation on mood-disturbance scores across time. Neither depression nor anxiety was affected by type of audio stimuli. Neither group showed any significant difference in levels of intrusive post-procedural memories or levels of dissociation. No participants demonstrated changes in dissociation post endoscopic examination. SCR differences showed physiological effects of priming with emotive words. Participants demonstrating implicit memory had significantly higher sleep disturbance scores than those with explicit memory for intra-procedural events. Conclusion –Hearing positive suggestion whilst under conscious sedation reduced intra-procedural distress and implicit memory for colonoscopy increased sleep disturbance in the days following the procedure. Evidence was found for midazolam sedation between 2-3mg impairing explicit memory whilst leaving implicit memory intact. Due to the low number of willing participants findings were tentative and difficult to generalise to a wider population.