Smalle, E. 1, 5 , Simonis, M. . 1 , Panouilleres, M. 2 , Muylle, M. 3 , Bogaerts, L. 3 , Page, M. . 4 , Duyck, W. 3 , Möttönen, R. 2 , Edwards, M. 1, 5 & Szmalec, A. 1, 3, 5
1 Psychological Sciences Research Institute, Université catholique de Louvain, Louvain-la-Neuve, Belgium
2 Department of Experimental Psychology, Oxford University, Oxford, United Kingdom
3 Department of Experimental Psychology, Ghent University, Ghent, Belgium
4 Department of Psychology, University of Hertfordshire, Hatfield, United Kingdom
5 Institute of Neuroscience, Université catholique de Louvain, Louvain-la-Neuve, Belgium
Why and how do children and adults differ in language learning? Due to a neurologically based maturational change at the level of the frontal and medial-temporal brain circuit, adults have access to explicit/declarative memory system using well-developed executive functions (EF) and attention. Children are thought to excel on implicit learning in an early-developing procedural memory system. We postulate the idea that learning certain aspects of words can be hindered by the declarative memory system, and aided by implicit learning mechanisms. In four studies, we show that human-memory theories and, in particular, theories about implicit serial-order learning, have the potential to improve our understanding of the cognitive processes that underpin various aspects of language acquisition across life. We demonstrate that children outperform adults on the implicit learning and offline retention of novel phonological sequences (study 1-3). We also show that late-developing EF in working memory, supported by the left dorsolateral prefrontal cortex, impair long-term serial-order learning of phonological sequences in adults by use of Transcranial Magnetic Stimulation (study 4). Overall, our findings contribute to a growing body of evidence regarding the involvement of two interacting long-term memory systems in skill acquisition, both across normal as well as pathological development.