Date of Award

Spring 1-1-2011

Document Type


Degree Name

Master of Arts (MA)


Speech, Language & Hearing Sciences

First Advisor

Phillip Gilley

Second Advisor

Brenda Schick

Third Advisor

Amy Thrasher


Research has shown that processing of modality specific stimuli begins early on in cortical processing, affecting the peaks of event related potentials that occur earlier in EEG waveforms. Processing of combined sensory inputs has been shown to affect the latency and amplitude of later occurring peaks, the N2 and P300, suggesting that sensory stimuli are processed in a combined manner in a later stage of cortical processing. Two of the earlier peaks, the N1 and P2, of auditory and visual event related potentials (ERPs) can be used to study the effects of multiple sensory inputs on the human sensory system. Using EEG to detect and record ERPs during a randomized single sensory and combined sensory detection task, this study examined whether or not a multisensory stimulus would affect the latency and amplitude of the auditory and visual N1 and P2 peaks. While outcomes of the study did not yield significant results for effects on the latency of the N1, there were significant effects for the amplitude of the N1 peak and the latency of the P2 peak; with the most significant results seen in an increase in amplitude of the P2 peak for the combined stimulus condition. Research Question: Are changes in the latency and amplitude of the N1 and P2 auditory and visual ERP peaks seen in multisensory processing, and if so, do these changes imply integration of multiple sensory inputs at earlier cortical stages of sensory processing?