Long-range correlations in choice sequences of schizophrenic patients

Schizophrenic patients significantly greater than normals exhibit long-range correlations in sequences of choices in a simple binary choice task. Moreover, schizophrenic patients also are significantly less influenced by external stimuli than are normal comparison subjects. These effects are not significantly correlated with each other, suggesting that they do not result from a uniform attentional deficit nor are they due to simple perseverative responding or any other uniform process. The interdependence of responses over many trials suggests that the response history of many previous behavioral responses contributes significantly to the temporal architecture of schizophrenic patients. In agreement with others (Lyon et al., 1994), we find that similar organizational principles apply to physical, economical, or biological systems and seem to play an important role in human psychopathology.