Minimal impact of consolidation on learned switch-readiness

Adaptive behavior is characterized by our ability to create, maintain, and update (or switch) rules by which we categorize and respond to stimuli across changing contexts (cognitive flexibility). Recent research suggests that people can link the control process of task-switching to contextual cues through associative learning, whereby the behavioral cost of switching is reduced for contexts that require frequent switching. However, the conditions that govern such learned cognitive flexibility are poorly understood. One major unanswered question is whether this type of learning benefits from memory consolidation effects. To address this question, we manipulated whether task-sets and/or specific task stimuli were more frequently linked with task-switching (vs. repeating), and ran participants over two experimental sessions, separated by a twenty-four-hour delay. We expected that consolidation would facilitate learned cognitive flexibility, resulting in a greater reduction of switch costs with increasing task-switch likelihood on session 2 compared to session 1. Across two experiments, we observed robust learning of stimulus and task-set related cognitive flexibility in both sessions. However, we found little evidence for effects of consolidation on learned cognitive flexibility, as the magnitude of the LWPS did not change from session 1 to 2. Taken together, our results suggest that people reliably and quickly acquire task-set and stimulus-based switch associations, but that this form of control learning – unlike many instances of reward-based learning – does not benefit from long-term memory consolidation. Possible reasons for these findings are discussed.