The role of somatic amplification in physical symptom reporting

Abstract

Despite their apparent ubiquity across healthcare settings medically unexplained symptoms (MUS) remain poorly understood. Theoretical models have proposed several different ways in which altered sensory and perceptual processes may contribute to the development and/or maintenance of MUS. The narrative review presented in Chapter 1 explores sensory and perceptual processes relevant to MUS and physical symptom reporting in general and considers whether current empirical findings lend support to a particular model or hypothesis. One conclusion of the review is that there is a paucity of research using objective methods to measure the putative role of somatic amplification during the perception of physical symptoms, and the influence of negative affect on this process. To address this shortfall, Chapter 2 presents an original study that attempts to test the effect of negative affect on somatic amplification, using a novel paradigm derived from signal detection theory (SDT), the somatic signal discrimination task (SSDiT). On the SSDiT, subjects are required to discriminate between a series of "weak" and "strong" vibrations. Nonclinical "high" and "low" symptom reporters completed this task prior to and following either a neutral or negative mood induction. Contrary to expectation, there was limited support for differences between symptom reporting groups on the SSDiT task at baseline. However, there was some suggestion that highs and lows may drift differentially on this task over time, such that lows showed a tendency to become more conservative than highs over time. Potential implications for theoretical models are discussed.Finally, Chapter 3 presents a critical evaluation in which the literature review and empirical study are placed within a wider context, allowing implications of the research process as a whole to be drawn out further. This chapter also identifies potential directions for future research, discusses limitations of the present thesis and offers personal reflections about the research process as a whole. This thesis follows the paper-based format, such that Chapters 1 and 2 are formatted as stand-alone papers considered suitable for publication, prepared in accordance with submission requirements for Clinical Psychology Review (Chapter 1) and Journal of Abnormal Psychology respectively (Chapter 2; see Appendix 1 for submission guidelines).

Date of Award	31 Dec 2011
Original language	English
Awarding Institution	The University of Manchester
Supervisor	Rachel Calam (Supervisor) & Richard Brown (Supervisor)