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Project

Interoceptive categorisation and symptom perception

Perceived sensations and symptoms often correspond poorly to the physiological state of the body. We proposed that the categorisation of bodily sensations (e.g., into categories of benign sensations vs. physical symptoms) is involved in this decoupling and may in extreme cases result in the perception of somatic symptoms in the absence of clear organic dysfunction – or functional somatic symptoms. More specifically, we expected that enhanced processing of affective-motivational aspects of the interoceptive experience (in some individuals and contexts) may bias interoception towards relying strongly on negatively valent categorical prior “beliefs” at the cost of sensory-perceptual information.

Eight inspiratory stimuli equidistant in intensity were allocated to two categories (either by ad hoc learning, or based on implicit categories). Participants rated intensity and unpleasantness of inspiratory stimuli, and identified them with a category label. We examined whether within-category differences were perceived (and sometimes memorised) with less detail than between-category differences. We also examined individual and contextual differences in this effect, as well as in categorical forced choice behaviour.

A first line of research aimed to replicate earlier interoceptive categorisation effects. We also aimed to investigate associations with factors expected to be related to increased affective-motivational processing. We examined relationships with (1) negative affectivity and habitual symptom reporting (Chapter 2), (2) disease relevance of categories, especially in high habitual symptom reporters (Chapter 3), and (3) threat relevance of categories (Chapter 4). We partly replicated earlier interoceptive categorisation effects, depending on the task design. Disease relevance was associated with more cautious categorisation behaviour and more detailed perception of stimuli within a benign sensation category, whereas threat relevance – partly – reduced perceived within-category detail. Negative affective traits were associated with better memory of between-category differences, instead of with a loss of sensory-perceptual detail within categories.

In a second line of research, we examined whether interoceptive categorisation effects were stronger in patients with functional somatic syndromes (FSS) than healthy individuals. We examined interoceptive categorisation in patients with functional dyspnoea symptoms (Chapter 5), assuming that respiratory sensations used in our study may be especially relevant to them. Moreover, we examined a broader sample of patients with FSS (fibromyalgia (FM) and/or chronic fatigue syndrome (CFS); Chapter 6), in order to investigate broader processing biases in patients with FSS. Interoceptive sensations were retrospectively less accurately identified by patients with functional dyspnoea symptoms, but not by patients with FM and/or CFS. Both patient groups showed deficits in new interoceptive category learning, but no specific tendency to misidentify sensations, nor less detailed perception of interoceptive sensations.

Our findings point to category-driven changes in interoceptive information sampling and thus support categorisation as a possible mechanism in reduced correspondence between perceived sensations and peripheral physiology, such as in functional somatic symptoms. Moreover, they suggest that sensory information sampling differs between and within individuals, depending on contextual factors and goals, pointing to variable interoceptive accuracy. Lastly, our results point to deficits in (new) learning about the state of the body in patients with FSS, possibly due to rigid existing interoceptive categories that reduce interoceptive accuracy in traditional interoception tasks.

Date:1 Oct 2015 →  2 Sep 2020
Keywords:Interoception, Categorization, Anxiety
Disciplines:Biological and physiological psychology, General psychology, Other psychology and cognitive sciences
Project type:PhD project