Brain activity during biofeedback relaxation - A functional neuroimaging investigation

The mechanisms by which cognitive processes influence states of bodily arou sal are important for understanding the pathogenesis and maintenance of str ess-related morbidity. We used PET to investigate cerebral activity relatin g to the cognitively driven modulation of sympathetic activity. Subjects we re trained to perform a biofeedback relaxation exercise that reflected elec trodermal activity and were subsequently scanned performing repetitions of four tasks: biofeedback relaxation, relaxation without biofeedback and two corresponding control conditions in which the subjects were instructed not to relax. Relaxation was associated with significant increases in left ante rior cingulate and globus pallidus activity, whereas no significant increas es in activity were associated with biofeedback compared with random feedba ck. The interaction between biofeedback and relaxation, highlighting activi ty unique to biofeedback relaxation, was associated with enhanced anterior cingulate and cerebellar vermal activity. These data implicate the anterior cingulate cortex in the intentional modulation of bodily arousal and sugge st a functional neuroanatomy of how cognitive states are integrated with bo dily responses. The findings have potential implications for a mechanistic account of how therapeutic interventions, such as relaxation training in st ress-related disorders, mediate their effects.