The impact of chronic psychosocial stress on corticomuscular responses to thermal pain stimulation

Psychosocial stress refers to the subjective experience and appraisal of real or potentially threatening psychosocial conditions. Pain is a complex physiological and psychological phenomenon, referring to unpleasant sensory and emotional experience associated with actual or potential tissue damage. To investigate the impact of chronic psychosocial stress on neural circuit responses to thermal pain, this study analyzed corticomuscular activities by electroencephalograph and electromyography. The results demonstrate that chronic psychosocial stress can change the cortical synchronization at α and γ frequencies and enhance motor unit recruitment under heat pain at both initial and progressive stages. Moreover, under progressive stimulation, pain-related neural feedback and localization functions may be disrupted, presenting impaired corticomuscular coherence. Therefore, chronic psychosocial stress can alter the integrated processing across both central and peripheral pathways, indicating a disintegration of the cortical-motor integration function of heat pain at initial and progressive stages.