Decoding the content of cross-modal influences in the brain

Bailey, Kerri (2020) Decoding the content of cross-modal influences in the brain. Doctoral thesis, University of East Anglia.

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Abstract

This thesis examined how context and prior experience can shape the neural computations occurring in the human brain, specifically by using pattern classification analysis to decode the content of cross-modal influences in and around the primary somatosensory cortex (S1). In Chapter 2, fMRI was used to investigate whether simply hearing familiar sounds depicting different hand-object interactions could be discriminated in S1, even though stimulus presentation occurred in the auditory domain and no external tactile stimulation occurred. Results found discriminable patterns of activity about the sound of different hand-object interactions in hand-sensitive areas of S1, and not our two control categories of familiar animal vocalizations and unfamiliar pure tones. Chapter 3 aimed to corroborate the cross-modal effects found in the previous fMRI literature using a high temporal resolution neuroimaging technique: EEG. Specifically, EEG was used to examine whether simply viewing images of different familiar visual object categories which imply rich haptic information could be identified in sensorimotor-related oscillatory responses, even though input was from a visual source and no tactile stimulation occurred. Results found the content of different familiar, but not unfamiliar, visual object categories could be discriminated in the mu rhythm oscillatory response, thus establishing a potential oscillatory marker for the cross-modal effects previously observed. Chapter 4 involved an interactive fMRI paradigm using real 3D objects to test whether the primary function of the cross-modal influences previously detected is a likely result of predictive coding mechanisms. Whilst no reliable evidence for an account of predictive coding was found in this experiment, this study provided critical insight into the development of experiments which can directly test the assumptions of predictive coding with real action. The research conducted in this thesis has, therefore, provided significant contributions to the literature regarding our understanding of cross-modal influences and cortical feedback in the human brain.

Keywords: cross-modal, cortical feedback, multi-voxel pattern analysis, mu rhythm, predictive coding, primary somatosensory cortex.

Item Type:	Thesis (Doctoral)
Faculty \ School:	Faculty of Social Sciences > School of Psychology
Depositing User:	Chris White
Date Deposited:	09 Dec 2020 09:37
Last Modified:	09 Dec 2020 09:37
URI:	https://ueaeprints.uea.ac.uk/id/eprint/77932
DOI:

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