title: Rapid and automatic speech-specific learning mechanism in human neocortex.
abstract: A unique feature of human communication system is our ability to rapidly acquire new words and build large vocabularies. However, its neurobiological foundations remain largely unknown. In an electrophysiological study optimally designed to probe this rapid formation of new word memory circuits, we employed acoustically controlled novel word-forms incorporating native and non-native speech sounds, while manipulating the subjects' attention on the input. We found a robust index of neurolexical memory-trace formation: a rapid enhancement of the brain's activation elicited by novel words during a short (~30min) perceptual exposure, underpinned by fronto-temporal cortical networks, and, importantly, correlated with behavioural learning outcomes. Crucially, this neural memory trace build-up took place regardless of focused attention on the input or any pre-existing or learnt semantics. Furthermore, it was found only for stimuli with native-language phonology, but not for acoustically closely matching non-native words. These findings demonstrate a specialised cortical mechanism for rapid, automatic and phonology-dependent formation of neural word memory circuits.
authors.affiliation: Cognitive Brain Research Unit, Cognitive Science, Institute of Behavioural Sciences, 00014 University of Helsinki, Finland. Electronic address: lilli.kimppa@helsinki.fi.
authors.forename: Lilli
authors.initials: L
authors.lastname: Kimppa
authors.affiliation: Cognitive Brain Research Unit, Cognitive Science, Institute of Behavioural Sciences, 00014 University of Helsinki, Finland; CICERO Learning, Institute of Behavioural Sciences, 00014 University of Helsinki, Finland.
authors.forename: Teija
authors.initials: T
authors.lastname: Kujala
authors.affiliation: Cognitive Brain Research Unit, Cognitive Science, Institute of Behavioural Sciences, 00014 University of Helsinki, Finland; Center of Functionally Integrative Neuroscience, Institute for Clinical Medicine, Aarhus University, 8000 Aarhus C, Denmark.
authors.forename: Alina
authors.initials: A
authors.lastname: Leminen
authors.affiliation: Phonetics and Speech Synthesis Research Group, Institute of Behavioural Sciences, 00014 University of Helsinki, Finland.
authors.forename: Martti
authors.initials: M
authors.lastname: Vainio
authors.affiliation: Center of Functionally Integrative Neuroscience, Institute for Clinical Medicine, Aarhus University, 8000 Aarhus C, Denmark; Centre for Cognition and Decision Making, NRU Higher School of Economics, Moscow, Russia.
authors.forename: Yury
authors.initials: Y
authors.lastname: Shtyrov
mesh_terms: D000328:Adult; D001288:Attention / Q000502:physiology*; D004569:Electroencephalography; D005260:Female; D005625:Frontal Lobe / Q000502:physiology; D006801:Humans; D007858:Learning / Q000502:physiology; D008297:Male; D011939:Mental Recall / Q000502:physiology*; D019579:Neocortex / Q000502:physiology*; D021641:Recognition, Psychology / Q000502:physiology*; D013067:Speech Perception / Q000502:physiology*; D013702:Temporal Lobe / Q000502:physiology; D055815:Young Adult
keywords: Electroencephalography; Event-related potentials; Language learning; Plasticity; Speech