Evaluating Individual Differences in Implicit Perceptual-Motor Learning: A Parallel Assessments Approach

Implicit learning describes learning from experience that is not available to conscious awareness. The question of whether some individuals are better implicit learners than others has suggested and may contribute to difference in performance among experts. Across four experiments, adult participants completed the Serial Interception Sequence Learning (SISL) task across multiple parallel learning assessment forms. Previously, SISL sequence-specific performance has been shown to resist explicit knowledge influence, allowing for repeated reassessments of implicit learning with novel statistical structure. Our findings indicate that group-level sequence-specific performance occurred robustly in each reassessment; however, participants who exhibited more sequence-specific performance on one assessment did not exhibit better performance on parallel assessments, indicating no rank-order stability in learning. In all four experiments, with two to twelve reassessments of learning, no participants exhibited consistently better sequence learning rates than the other participants, indicating no evidence for a better ability in implicit learning. Measurements of other cognitive constructs, such as processing speed collected in parallel, exhibited robust individual differences. In Experiment 4, a general battery of cognitive measurements showed typical individual differences in measures of working memory, processing speed, and personality, but none correlated with implicit learning ability. We hypothesize that implicit learning arises from a general process of neuroplasticity reorganizing functions during practice and that our findings suggest that this process occurs at a basically similar rate across all people. Everybody learns from practice implicitly, but results suggest that the learning rate does not vary substantially across this sample.