Cognitive subprocesses and schizophrenia. B. Maze tasks

Objective: In a companion paper we demonstrated that in reaction-time tasks the response selection stage is selectively disturbed in schizophrenia. Th e aim of the present study is the investigation of subprocesses, which are incorporated into repeatedly activated loops of cognitive processes and nee d additional information from working memory. Method: Maze tasks of varying complexity (with and without bifurcations) we re presented to drug-naive and treated first-onset schizophrenic patients. The tasks had to be solved under easy and difficult motor-conditions Both p atient samples were compared with healthy control groups matched by age, se x, education and experience with the experimental setting. Results: In mazes with alternative routes patients exhibited the expected d ecrease of performance. However, untreated patients improved under difficul t motor conditions. This improvement is smaller after neuroleptic treatment . Conclusion: Under difficult motor conditions attention is focused on the ex ecution of movements and thus withdrawn from perceiving irrelevant response alternatives, i.e. the effects of disturbed response selection are reduced .