title: Flexible, rapid and automatic neocortical word form acquisition mechanism in children as revealed by neuromagnetic brain response dynamics.
abstract: Children learn new words and word forms with ease, often acquiring a new word after very few repetitions. Recent neurophysiological research on word form acquisition in adults indicates that novel words can be acquired within minutes of repetitive exposure to them, regardless of the individual's focused attention on the speech input. Although it is well-known that children surpass adults in language acquisition, the developmental aspects of such rapid and automatic neural acquisition mechanisms remain unexplored. To address this open question, we used magnetoencephalography (MEG) to scrutinise brain dynamics elicited by spoken words and word-like sounds in healthy monolingual (Danish) children throughout a 20-min repetitive passive exposure session. We found rapid neural dynamics manifested as an enhancement of early (~100ms) brain activity over the short exposure session, with distinct spatiotemporal patterns for different novel sounds. For novel Danish word forms, signs of such enhancement were seen in the left temporal regions only, suggesting reliance on pre-existing language circuits for acquisition of novel word forms with native phonology. In contrast, exposure both to novel word forms with non-native phonology and to novel non-speech sounds led to activity enhancement in both left and right hemispheres, suggesting that more wide-spread cortical networks contribute to the build-up of memory traces for non-native and non-speech sounds. Similar studies in adults have previously reported more sluggish (~15-25min, as opposed to 4min in the present study) or non-existent neural dynamics for non-native sound acquisition, which might be indicative of a higher degree of plasticity in the children's brain. Overall, the results indicate a rapid and highly plastic mechanism for a dynamic build-up of memory traces for novel acoustic information in the children's brain that operates automatically and recruits bilateral temporal cortical circuits.
authors.affiliation: Center of Functionally Integrative Neuroscience (CFIN), Department of Clinical Medicine, Aarhus University, Aarhus, Denmark; Cognitive Brain Research Unit, Institute of Behavioural Sciences, University of Helsinki, Finland. Electronic address: eino.partanen@helsinki.fi.
authors.forename: Eino
authors.initials: E
authors.lastname: Partanen
authors.affiliation: Center of Functionally Integrative Neuroscience (CFIN), Department of Clinical Medicine, Aarhus University, Aarhus, Denmark; Cognitive Brain Research Unit, Institute of Behavioural Sciences, University of Helsinki, Finland.
authors.forename: Alina
authors.initials: A
authors.lastname: Leminen
authors.affiliation: Center of Functionally Integrative Neuroscience (CFIN), Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.
authors.forename: Stine
authors.initials: S
authors.lastname: de Paoli
authors.affiliation: Center of Functionally Integrative Neuroscience (CFIN), Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.
authors.forename: Anette
authors.initials: A
authors.lastname: Bundgaard
authors.affiliation: Center on Autobiographical Memory Research (CON AMORE), Department of Psychology and Behavioural Sciences, Aarhus University, Denmark.
authors.forename: Osman Skjold
authors.initials: OS
authors.lastname: Kingo
authors.affiliation: Center on Autobiographical Memory Research (CON AMORE), Department of Psychology and Behavioural Sciences, Aarhus University, Denmark.
authors.forename: Peter
authors.initials: P
authors.lastname: Krøjgaard
authors.affiliation: Center of Functionally Integrative Neuroscience (CFIN), Department of Clinical Medicine, Aarhus University, Aarhus, Denmark; Laboratory of Behavioural Neurodynamics, Saint Petersburg State University, Saint Petersburg, Russian Federation; Centre for Cognition and Decision Making, NRU Higher School of Economics, Moscow, Russian Federation.
authors.forename: Yury
authors.initials: Y
authors.lastname: Shtyrov
mesh_terms: D002540:Cerebral Cortex / Q000502:physiology*; D002648:Child; D002657:Child Development / Q000502:physiology*; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007802:Language; D007858:Learning / Q000502:physiology*; D015225:Magnetoencephalography / Q000379:methods*; D008297:Male; D013067:Speech Perception / Q000502:physiology*; D013997:Time Factors
keywords: Children; Development; ERF; Language; Learning; MEG