Dichotic monitoring and focused versus divided attention in schizophrenia.

The target detection performance of normals, chronic schizophrenics with positive symptoms and those with negative symptoms was compared in focused and divided attention conditions. The focused condition involved the monitoring of one, and the divided condition the monitoring of both, of the dichotically presented word lists. The amount and rate of list presentations were held constant across the conditions in an attempt to separate attentional from difficulty and capacity factors. Results showed that while the overall performance of both schizophrenic groups was lower than that of the normals, their performance change from the focused to the divided attention condition did not differ from that of the normals. These results do not support a schizophrenic selective attention deficit hypothesis.