Repeated exposure to aversive sensations differentially affects neural gating and bodily perception

Habituation to bodily sensations is highly relevant for the experience of chronic bodily symptoms, but the neural mechanisms behind diminished habituation are currently unclear. One potentially relevant mechanism is neural gating (NG), reflected as the short-term suppression of cortical responses to redundant stimuli. We investigated the effects of repeated exposure to aversive sensations on NG and subjective perception in 91 healthy adults, by measuring their NG of respiratory and electrocutaneous stimuli using electroencephalography during two sessions separated by one week, in addition to their self-report of intensity and unpleasantness of the sensations. To test for intra- and cross-modal effects, 1/2 participants returned three times in the intervening week to experience additional aversive respiratory stimulation, while the other 1/2 received aversive electrocutaneous stimulation. Participants reported lower unpleasantness of all sensations in the final session (intra- and cross-modal habituation). NG was improved for respiratory sensations only in the group receiving additional respiratory stimulation (intra-modal habituation). We found no relationships between NG and perceptual habituation, adding to the mixed results on the relevance of NG to perceptual changes in healthy adults. Future research with clinical populations and different methods is encouraged to further clarify the mechanisms behind neural gating and diminished symptom habituation.