| Abstract: | Letter-naming and dot enumeration tasks, designed to elicit left and right hemisphere functioning, respectively, were presented tachistoscopically to paranoid and nonparanoid schizophrenics, nonschizophrenic psychiatry controls, and normal subjects. Types of information-processing used by paranoid and nonparanoid schizophrenics were also examined. All groups identified letters with greater accuracy with left hemisphere presentation. Group differences in the letter task disappeared once education was controlled. No hemisphere effect was found for dot enumeration but group differences emerged. As predicted, paranoids and controls processed the dots serially and hence decreased in accuracy over frame size. Nonparanoids processed in an automatic mode, revealing the same degree of accuracy over all dot sizes. The poorer performance of the nonparanoids in dot enumeration is discussed in terms of the task requiring bilateral processing and the nonparanoids' failure to integrate the processing of left and right hemispheres. |
