COGNITIVE CORRELATES OF FUNCTIONAL AND DYSFUNCTIONAL IMPULSIVITY

According to Dickman (1990), functional impulsivity (measured by the Dickman Impulsivity Inventory) is associated with rapid error-prone processing on a cognitive matching task, whereas dysfunctional impulsives (classified according to responses on the same inventory) are not distinguishable from non-impulsives in terms of information processing style. The present study tested the hypotheses that whereas functional impulsivity is associated with a rapid information processing style, dysfunctional impulsivity may be associated with an inability to inhibit competing responses, as measured by the Stroop colour-word interference task. The results of step-wise multiple regression analyses supported the hypotheses. Functional impulsivity was the only significant predictor of reaction times on both a Stroop task and a control colour-word matching task, whereas dysfunctional impulsivity was the only significant predictor of errors on a Stroop task. Dysfunctional impulsivity did not predict errors on the control task. The results suggest that functional and dysfunctional impulsivity may have different underlying cognitive concomitants.