Kiss, M. 1, 3 , Nemeth, D. 2, 3, 4 & Janacsek, K. 2, 3
1 Department of Cognitive Science, Budapest University of Technology and Economics, Budapest, Hungary
2 Institute of Psychology, ELTE Eötvös Loránd University, Budapest, Hungary
3 Brain, Memory and Language Research Group, Institute of Cognitive Neuroscience and Psychology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
4 Lyon Neuroscience Research Center (CRNL), Université de Lyon, Lyon, France
Implicit skill learning occurs in a gradual and progressive manner over a longer time interval. Nevertheless, most studies focused on the early phase of learning tested in a relatively short time interval. Here we aimed to comprehensively characterize how various aspects of performance changes over extended practice and test the resistance to interference of the acquired knowledge after this extended period. We used the Alternating Serial Reaction Time task (ASRT) to measure implicit probabilistic sequence learning. There were ten sessions in the experiment, with one week delay between the consecutive sessions. Participants (N = 25) performed the ASRT task with the same sequence in the first eight sessions, then an interfering sequence was introduced in Session 9, and both (original and interfering) sequences were tested in Session 10. We found that dynamic changes occur in performance throughout all sessions, including changes in speed and accuracy. Learning of triplet probabilities (statistical learning) occurs early and increases with practice. In contrast, learning of the higher-order sequence structure emerges later during practice. Both knowledge shows resistance to interference. These findings provide deeper insights into the dynamic changes of learning and performance of various aspects of implicit skill learning.