Personality differences in cognitive control? BAS, processing efficiency, and the prefrontal cortex

Abstract

Emotion and cognition can be viewed as complementary behavioral control systems, both of which show considerable variation across individuals. We tested the hypothesis that affective individual differences in behavioral activation (i.e., approach tendencies) are related to individual differences in cognitive control functions of the prefrontal cortex (loosely, executive function). Our guiding intuition was that individual differences in reward responsiveness might be related to differences in goal-directed (reward seeking) cognitive control processes. Working memory tasks can greatly tax cognitive control, and specific areas within the prefrontal cortex (PFC) are known to be sensitive to working memory load. Behavioral studies have shown that extraverts can have slightly better working memory performance than introverts (Humphreys & Revelle, 1984; Lieberman & Rosenthal, 2001). Given our theoretical interest in reward responsiveness, which is similar but not necessarily identical to extraversion, we first replicated this finding using measures of Behavioral Activation Sensitivity (BAS) (Carver & White, 1994). Consistent with prior work on extraversion, higher BAS predicted slightly better working memory performance the first time participants performed a challenging working memory task, the 3-back task (in which participants see items, such as a words or faces, displayed every few seconds on a computer screen, and have to indicate whether a current item exactly matches the one they saw three items previously). The task places high demands on cognitive control by requiring participants to actively maintain information (e.g., a word) in the face of distraction (two intervening words), and then respond on the basis of that information. However, with repeated administration of the task, this effect reversed leading to no main effect of BAS on performance but a strong interaction of BAS with time (task repetition). In hindsight