Dichotic listening and recall in schizophrenia and mania.

Schizophrenic (n = 20), manic, (n = 16), and normal (n = 16) subjects were examined for their ability to shadow information dichotically and recall it. Text passages were varied in their level of organization and presented in the presence and absence of distraction. Schizophrenic patients were the only subjects affected by the presence of distraction, and this effect was specific to shadowing and not to recall. The severity of positive thought disorder was related to the three shadowing variables in the schizophrenic subjects but not in the manic sample. Closer examination revealed that performance under distraction was specifically related to thought disorder on one variable: the ability to monitor the level of organization in passages that they were shadowing. The implications of these results for research identifying causes and correlates of thought disorder are discussed.