ENLARGED FRONTAL P300 TO STIMULUS CHANGE IN PANIC DISORDER

This study investigated event-related potential (ERP) indices of infor mation processing in sufferers of panic disorder (PD). ERPs were recor ded from 14 PD patients and 15 controls during an auditory target dete ction task. The task required subjects to discriminate infrequent targ et tones (p =.14; 2000 Hz) from frequent (p = .72; 1000 Hz) and infreq uent (p = .14; 500 Hz) distracter tones. A frontal P300 (P3a) identifi ed in the PD group was characteristic of activity that would be expect ed to novel task-irrelevant stimuli and is consistent with functional pathology involving the prefrontal-limbic pathways. This study provide s psychophysiological evidence of art abnormality in PD of the brain's processing of physical changes in the stimulus field that occurs even under conditions of low stimulus load. It may assist in helping to un derstand the breakdown in information processing that occurs in PD und er high load conditions such as crowds and supermarkets.