The Stroop effect in schizophrenic patients.

Schizophrenic patients (n = 44) and normal controls (n = 50) performed a computerized version of the Stroop color-word interference task. Schizophrenic patients generally showed more Stroop interference than normal subjects. The effect was neither related to demographic variables, nor to actual psychopathology. However, the course of the disorder was related to the Stroop effect, in that acute, chronic, and schizoaffective patients displayed a larger interference effect than patients with a recurrent episode. From a methodological perspective, the computerized version of the Stroop task proved to be more sensitive to interference effects in the patient group. The finding of enhanced reverse Stroop interference in patients strongly preoccupied with colors is discussed within the framework of MacLeod and Dunbar's (MacLeod and Dunbar, 1988) theory of Stroop interference involving differential practice effects.