Objective: The Search Identification Task (SIT) is a novel, paper and pencil cancellation test that assesses attention in addition to psychomotor speed and aspects of executive functions. The SIT consists of two parts, one letters and one figures, that require participants to scan for special targets of increasing difficulty, with two alternate forms. The current study investigates performance on the SIT in schizophrenia, a group known to have attention deficits, to examine SIT utility in a clinical population. Method: Twenty-two healthy controls and 22 individuals diagnosed with schizophrenia were evaluated. There were no significant differences between groups on age, gender, or ethnicity. Participants were administered either SIT form A or form B, and block design, coding, digit span, and similarities subtests of the WAIS-III. Results: The repeated measures ANOVA examining SIT total scores for letters and figures on forms A and B found a significant main effect for group and stimulus (i.e., letter or figure) but no interaction effects were found. Also, the SIT letter and figure total scores significantly correlated with all subtests of the WAIS-III. Both SIT scores correlated the strongest with the coding subtest. Conclusion(s): Results provide support for utility of the SIT in clinical populations. As expected, the schizophrenia group performed significantly worse than controls. Both groups performed significantly worse on figures compared to letters. This is not surprising, as unfamiliar figures are typically more difficult to process than familiar figures (i.e., letters). Correlations with WAIS-III subtests suggest that processing speed is a main predictor of SIT performance.
NEUROPSYCHOLOGICAL DOMAINS: EXECUTIVE FUNCTIONS