THE RELATION BETWEEN EVENT-RELATED BRAIN POTENTIAL, HEART-RATE, AND BLOOD-PRESSURE RESPONSES IN AN S-1-S-2 PARADIGM

Event-related brain potential (ERP), heart rate (HR), and blood pressu re (BP) responses were examined during the 6 s foreperiod of a choice- reaction task. Low and high trait-anxious males were required to make same/different judgements based on the similarity of two successively presented visual patterns. The pitch of a warning tone, presented at t he beginning of the foreperiod, indicated whether speed or accuracy wa s to be emphasized on that trial. In different conditions, subjects re ceived either a monetary reward or aversive noise, depending on their performance. Two clusters of parallel variations were observed in the foreperiod: (1) speed/accuracy instructions affected the amplitude of the CNV and, in interaction with anxiety group, the initial decreases in HR and diastolic BP; (2) type of reward, in interaction with speed/ accuracy instructions, affected the amplitude of the P300 and PSW, the mid-interval HR acceleration, and subsequent increases in diastolic a nd systolic BP. A correlational analysis showed a close relationship b etween changes in HR and BP, whereas no relationship was evident betwe en changes in ERPs and changes in HR and BP.