This annotation describes psychophysiological research that has examined the hypothesis that autonomic hyperarousal is a possible mediating factor between schizophrenic relapse and psychosocial influences such as expressed emotion (EE) and life events. We review several studies that have measured psychophysiological activity in schizophrenic patients while in the presence of their relatives. The findings from this area of research are compared with those of other psychophysiological studies of schizophrenia which have employed more traditional laboratory tasks such as the electrodermal response-habituation paradigm. Finally, some conclusions are drawn regarding the clinical implications of psychophysiological research, and areas for future investigation are suggested.