The effect of motivation on loose thinking in schizophrenics as measured by the Bannister-Fransella Grid Test.

Administered the Bannister-Fransella Grid Test of Schizophrenic Thought Disorder to 40 male schizophrenics. Half of them received a monetary reward for their performance, and half did not. The efficacy of this motivation-enhancing manipulation was verified by the fact that the group that was working for the money completed a card sorting task significantly faster than the group that received no compensation. However, the former group also exhibited more thought disorder on the grid test. The results were interpreted in terms of drive theory. It was argued that the rewarded group was more motivated and therefore more highly aroused and that this high arousal level disrupted performance on the more complex task. The findings do not support the hypothesis that lack of motivation contributes to schizophrenic cognitive deficit.