Minimal phrase composition revealed by intracranial recordings
Elliot Murphy
May 2021 

The ability to comprehend phrases is an essential component of language. Here we evaluate the neural processes that enable the transition from single word processing to a minimal compositional scheme using intracranial recordings. 19 patients implanted with penetrating depth or surface subdural intracranial electrodes heard auditory recordings of adjective-noun, pseudoword-noun and adjective-pseudoword phrases and judged whether the phrase matched a picture. Stimulus-dependent alterations in broadband gamma power activity (BGA), low frequency power or phase consistency, and phase-locking values across the compositional network were analyzed. The posterior superior temporal sulcus (pSTS) and temporo-occipital junction (TOJ) revealed a fine-structured cortical mosaic, with closely neighboring tissue displaying exclusive sensitivity to either lexicality or phrase structure, but not both. During phrase composition, greater functional connectivity was seen between pSTS-TOJ and both pars triangularis and temporal pole. These two regions also encode anticipation of composition in broadband low frequencies. These results implicate pSTS-TOJ as a crucial hub for the retrieval and computation of minimal phrases. Overall, this work reveals an interface of sparsely interwoven coding for lower and higher level linguistic features, coupled with large-scale network organization, with direct relevance to our understanding of cognitive networks in the human brain.

Format:	[ pdf ]
Reference:	lingbuzz/005934 (please use that when you cite this article)
Published in:	bioRxiv
keywords:	composition, electrocorticography, semantics, posterior temporal lobe, anticipation, human, language, semantics, syntax
Downloaded:	318 times

 

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