EEG and autonomic indices were measured in basal, tonic, and phasic conditions in order to delineate the nature of arousal dysfunction in schizophrenics as compared to normals. The experimental procedure involved six continuous recording sessions consisting of a basal recording before and after four experimental series. Sequentially, these were the visual nonsignal (VNS), the auditory nonsignal (ANS), the visual signal (VS), and the auditory signal (AS) series. The main findings indicated significant differences between the two groups in cardiovascular indices during the basal and tonic conditions and in the EEG and EMG indices of phasic response. These results suggest a dysfunction of basal and tonic autonomic arousal and a modulatory impairement of the central phasic arousal reaction. The findings are in accordance with the two arousal hypothesis postulated by Routtenberg (1968) and disconfirm the unitary concept of arousal for the explanation of psychophysiological abnormality in schizophrenia.