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Abstract:
We present a neural architecture for assigning (binding)
arguments (nouns) to verbs in syntactic processing. The assignment
of arguments to verbs is determined by the argument structure of
the verbs and by the syntactic structure of the sentence. Argument
structures and syntactic rules are implemented with neural circuits
consisting of interacting cortical assemblies. Binding of verbs and
arguments occurs in neural assembly structures that function as
interface structures between verbs and arguments. Particular
assemblies in the neural circuits and interface structures function
as working memory. Thus, working memory is distributed over the
architecture and plays a crucial role in syntactic processing and
the binding of verbs and arguments. Working memory is implemented
as delay activity in the working memory assemblies. We model delay
activity in working memory assemblies on the basis of delay
activity in working memory assemblies found in the prefrontal
cortex (PFC). In contrast with working memory in PFC, however,
multiple active working memory assemblies are possible in our
architecture, which is vital for the storage of multiple
verb-argument bindings. Activity in a working memory assembly does
not end by explicit inhibition, but decays gradually over time due
to overall activity in the neural architecture. Individual
differences in working memory can be accounted for in terms of the
structure and coherence of the working memory assemblies
involved.
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