title: A semantic model to study neural organization of language in bilingualism.
abstract: A neural network model of object semantic representation is used to simulate learning of new words from a foreign language. The network consists of feature areas, devoted to description of object properties, and a lexical area, devoted to words representation. Neurons in the feature areas are implemented as Wilson-Cowan oscillators, to allow segmentation of different simultaneous objects via gamma-band synchronization. Excitatory synapses among neurons in the feature and lexical areas are learned, during a training phase, via a Hebbian rule. In this work, we first assume that some words in the first language (L1) and the corresponding object representations are initially learned during a preliminary training phase. Subsequently, second-language (L2) words are learned by simultaneously presenting the new word together with the L1 one. A competitive mechanism between the two words is also implemented by the use of inhibitory interneurons. Simulations show that, after a weak training, the L2 word allows retrieval of the object properties but requires engagement of the first language. Conversely, after a prolonged training, the L2 word becomes able to retrieve object per se. In this case, a conflict between words can occur, requiring a higher-level decision mechanism.
authors.affiliation: Department of Electronics, Computer Science and Systems, University of Bologna, Viale Risorgimento 2, I40136 Bologna, Italy. mauro.ursino@unibo.it
authors.forename: M
authors.initials: M
authors.lastname: Ursino
authors.forename: C
authors.initials: C
authors.lastname: Cuppini
authors.forename: E
authors.initials: E
authors.lastname: Magosso
mesh_terms: D000200:Action Potentials / Q000502:physiology; D001185:Artificial Intelligence; D001683:Biological Clocks / Q000502:physiology; D001921:Brain / Q000502:physiology*; D005071:Evoked Potentials / Q000502:physiology; D006801:Humans; D007802:Language; D007858:Learning / Q000502:physiology; D008432:Mathematical Computing; D055641:Mathematical Concepts; D008568:Memory / Q000502:physiology; D019303:Multilingualism; D009415:Nerve Net / Q000502:physiology*; D016571:Neural Networks, Computer; D009474:Neurons / Q000502:physiology; D012660:Semantics; D009435:Synaptic Transmission / Q000502:physiology