Increased temporal patterns in choice responding and altered cognitive processes in schizophrenia and mania

The THEME method for measuring time-determined patterns (T-patterns) in behavior has been suggested as a new, more objective method for assessing cognitive disturbances in schizophrenia.

THEME was used to compare responses of schizophrenic patients with those having mood, schizoaffective, or severe anxiety disorders, and with healthy control subjects.

A two-choice, button-pressing task was used to elicit T-patterns among responses, with knowledge-of-results (K) rewards and coin reinforcements (RF) as reinforcers. Subjects were compared by diagnosis, drug treatment, and gender.

Schizophrenic and manic patients showed excessive numbers of, and more complex T-patterns than controls. Schizophrenic and manic patients frequently demonstrated repetitive (stereotyped) responding, an effect never seen in healthy controls. Although clozapine (CLZ) reduced both excessive T-pattern structure and stereotyped responding, it also reduced growth of responding to the coin RF.

Significant T-pattern increases may represent a common, time-related symptom of schizophrenia and mania. CLZ's effect on T-pattern production suggests that receptor effects other than the DAD(2) antagonism of "typical" neuroleptics' may be relevant to these findings.