Fischer-Baum, Simon J2019-05-172019-05-172018-082018-06-21August 201Noe, Colin. "Measuring Top-Down Influence onto Sub-Lexical Speech Perception." (2018) Master’s Thesis, Rice University. <a href="https://hdl.handle.net/1911/105791">https://hdl.handle.net/1911/105791</a>.https://hdl.handle.net/1911/105791Speech perception theories differ on whether the process of sub-lexical speech perception is autonomous or is influenced by contextual knowledge such as semantic or lexical context. A better understanding of sub-lexical speech perception would be useful for building cognitive models of speech perception and clinically, in understanding speech perception deficits after neurological injury. We employ the N1 EEG-ERP waveform to measure the sub-lexical processes involved in stop-consonant voicing categorization and test whether voicing encoding is altered by lexical status (e.g. /d/-/t/ in dape-tape versus date-tate). This project improves on previous work investigating sub-lexical perception (e.g. Ganong, 1980) by including an online measure of sub-lexical encoding. We demonstrate effects of lexical context on N1 encoding, indicating interaction of lexical and sub-lexical information. This finding supports online feedback accounts of speech perception. Practically, it also confirms the N1-EEG is a useful candidate for measuring deficits in speech perception in neurologically damaged populations.application/pdfengCopyright is held by the author, unless otherwise indicated. Permission to reuse, publish, or reproduce the work beyond the bounds of fair use or other exemptions to copyright law must be obtained from the copyright holder.Speech PerceptionN1EEGTop-Down InfluenceThesis2019-05-17