Thompson, K. R., Sanchez, D. J., Wesley, A. H., & Reber, P. J. (submitted). Ego depletion slows implicit skill learning.
Implicit skill learning occurs incidentally and without conscious awareness of what is learned. However, the rate and effectiveness of learning may still be affected by decreased availability of central processing resources during practice. Dual-task experiments have generally found impairments in implicit learning, however, these studies have also shown that certain characteristics of the secondary task (e.g., timing) can complicate the interpretation of these results. To avoid this problem, the current experiments used a novel method to impose resource constraints prior to engaging in skill learning. Ego depletion theory states that humans possess a limited store of cognitive resources that, when depleted, results in deficits in self-regulation and cognitive control. In a first experiment, we used a standard ego depletion manipulation prior to learning of an implicit motor sequence using the Serial Interception Sequence Learning (SISL) task. Depleted participants exhibited less learning than did non-depleted controls, indicating that constraining available executive resources slows implicit sequence learning. In a second experiment, depletion was administered either prior to or after training. Post-hoc analyses revealed an influence of individual differences in depletion susceptibility on subsequent learning and again showed a general slowing in learning, but did not allow for clear separation of ego depletion effects on learning versus skilled performance. These results indicate that even implicit learning can be impaired by reduction in executive resources and implies that in both training and educational contexts, ego depletion should be avoided prior to practice to maximize training gains even from rote or repetitive practice.