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On Broca, brain, and binding| old_uid | 5095 |
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| title | On Broca, brain, and binding |
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| start_date | 2008/06/16 |
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| schedule | 11h-12h30 |
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| online | no |
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| summary | In this presentation, the outlines will be sketched of a neurobiologically inspired model of language processing, referred to as the MUC-model (Memory, Unification, Control). This model distinguishes three components, the first one is the Memory component, also referred to as the mental lexicon. This contains the information about the words and rules of language. The Unification component binds lexically retrieved information into a higher level representation at three levels : phonological, syntactic and conceptual/semantic. The Control component deals with executive control necessary for turn-taking, selection of a language in a bilingual brain, etc. The focus will be mainly on Unification operations. Form a neurobiological perspective, a part of frontal cortex, including Broca’s area (LIPC) is well-suited for Unification operations. LIPC is a set of related brain areas with contributions to multiple functions and subregional relative specializations. Broca’s area and adjacent cortex is part of prefrontal cortex, an area known to be specialized for keeping information on-line over time, and for performing operations on activated representations. It will be proposed that for language functions such as speaking and listening LIPC is involved in maintaining the activational state of representational structures retrieved from memory (the mental lexicon), and to provide the necessary neuroanatomical space for unifications between representational structures. In addition an anterior-to-posterior gradient in unification (binding) operations is present, with anterior parts of LIPC involved in semantic binding, middle parts in syntactic binding, and posterior parts in phonological binding. Evidence in favor of the model will be presented, based on data from event related brain potential (ERP) recordings, studies using Magnetoencephalography (MEG), and functional Magnetic Resonance Imaging (fMRI). Furthermore, evidence will be presented against a privileged position of syntax and/or a processing priority for syntax, as assumed in syntax-first models. The different processing levels (phonological, syntactic, conceptual/semantic) operate in parallel, and, to some degree independent. Where necessary, cross-talk takes place, which is characterized by the immediacy principle. Immediacy is the general processing principle of unification. Unification operations do not wait until relevant syntactic information (such as word class information) is available, but starts immediately with what it derives on the basis of the bottom-up input and the left context. The corollary of immediacy is incrementality : Output representations are built up from left to right in close temporal contiguity to the input signal. Cross-talk between phonological, syntactic and semantic sources of information takes place on a more or less moment-to-moment basis. |
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| responsibles | Information non disponible |
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