Human brain potentials reveal similar processing of non-linguistic abstract structure and linguistic syntactic structure

Abstract

This research tested the hypothesis that shared or related neurophysiological processes are required for treating (a) non-linguistic abstract structure and (b) some aspects of linguistic syntactic structure. In language, one syntactic structure can be used to create an open class of sentences. We have previously proposed a relation between this generative aspect of syntactic structure and the abstract structure of non-linguistic sequences. For instance, the sequences ‘ABCBAC’ and ‘DEFEDF’ have different serial order or serial structure, but share the same abstract structure ‘123213’. Our recent studies of neuropsychology, simulation and ERPs argued that similar neurophysiological processes are involved in treating non-linguistic abstract structure and certain aspects of linguistic syntactic structure. The current research tests this hypothesis by examining the ERP profile evoked during the processing of non-linguistic sequences vs. sentences. Ten healthy subjects were trained to discriminate between syntactically correct and incorrect sequences and sentences presented visually on a video screen. During the subsequent ERP recording, subjects discriminated between correct and incorrect sequences and sentences presented visually on the screen. This discrimination task yielded, for anomalies in both the abstract and syntactic conditions, a late positivity around 550 ms with partially overlapping topography. These results support our hypothesis that shared or related neurophysiological processes are required for treating non-linguistic abstract structure and aspects of linguistic syntactic structure. However, they also suggest that the overlap between these two types of processing is not complete.