Performance characteristics of chronic schizophrenia on attention tests sensitive to unilateral brain damage.

The aims of this study were to investigate the lateralization hypothesis of schizophrenia, comparing chronic schizophrenics with unilateral brain-damaged subjects and normal controls, using attentional tests sensitive to the unilateral brain damage. Three attentional tests with different modes of stimuli, two vigilance tasks that require the self-paced or nonself-paced responses of subjects and one divided attention task, were administered to 28 chronic schizophrenics, 26 right and 24 left unilateral brain-damaged subjects, and 20 normal controls. The results indicated that schizophrenics performed a possible right-hemisphere damages pattern and also a left pattern in part, with failure of all tasks to show either pattern related to a number of differences between the three tasks. Furthermore, the attention deficits of schizophrenics are less than those of brain-damaged subjects but are clearly abnormal compared with the normal controls.