Modified Stroop Test as a Measure of Cognitive Impairment in Schizophrenia

The purpose of this study was to examine the differences in the mean recall productivity, as measured by the modified Stroop test, between a group of adults diagnosed with schizophrenia and healthy individuals. Archival data were used to construct 2 demographically matched research samples, and a 2-way between and within subjects ANOVA (2X3) was conducted to determine the impact of the test condition (congruent, neutral, and conflict), group type (patients and healthy controls), as well as the interaction of these factors on the dependent variable, measured as the average number of correctly recalled stimuli. Kahneman's model of attention and Frith's model of schizophrenia were drawn upon to explain the results. A significant main effect was found for the within-subjects variable (test condition): Both patients with schizophrenia (n=33) and healthy controls (n=28) recalled significantly fewer items in the conflict condition relative to the neutral, and in the neutral-relative to the congruent condition. A significant main effect for the between-subjects factor was found as well: Patients with schizophrenia demonstrated significantly lower recall productivity in all test conditions compared to healthy participants. No statistically significant effect was found for the interaction of independent variables. The findings of this study suggest, among other things, that patients with schizophrenia utilize suboptimal cognitive strategies when performing a modified Stroop task. Increasing the variability of cognitive strategies used by the patients may contribute to a reduction of schizophrenia cognitive deficit thus facilitating patients' independent living skills and integration with the community, as well as reducing societal spending on schizophrenia treatment to effect social change.