Most pain studies have focused on only two aspects: the influence of pain on attentional processing and the modulation of pain perception by affective stimuli.
However, the influence of tonic pain on the attentional processing of affective stimuli has not been studied. In this study, Guzmán Alba, Jaime Vila and Miguel Ángel Muñoz, CIMCYC researchers, investigated the effects of tonic pain on attentional processing of affective stimuli, focusing on autonomic responses and their relationship with both electroencephalogram (EEG) power and functional connectivity.
Forty people (20 men and 20 women) participated in this study. Participants received tonically painful and non-painful thermal stimulation while viewing pleasant, unpleasant or neutral images. Galvanic skin conductance response (SCR), electrocardiographic activity, and EEG activity in the delta and theta bands (which are associated with attentional processing of affective stimuli) were recorded.
Typical affective SCR and heart rate (HR) patterns were found in the no pain condition, but when pain was delivered, these patterns disappeared. EEG power and functional connectivity results showed that tonic pain affected the delta band in the central region during pleasant and unpleasant image blocks.
These results suggest that tonic pain captured attentional focus and reduced the cognitive resources available for processing affective stimuli, altering the emotional experience associated with pain.
Alba, G., Vila, J., Miranda, J. G. V., Montoya, P., & Muñoz, M. A. (2022). Tonic pain reduces autonomic responses and EEG functional connectivity elicited by affective stimuli. Psychophysiology. https://doi.org/10.1111/psyp.14018