THE EFFECTS OF AGING ON AUDIO-VISUAL TEMPORAL PROCESSING: MULTISENOSRY INTEGRATION OR PREDICTION?

Abstract

Aging is associated with a decrease in sensory temporal processing, which potentially leads to detrimental perceptual consequences. Due to age-related facilitation in multisensory processing and the multimodal nature of sensory environment the aging in multisensory context was investigated. More specifically, we wanted to explore whether age-related decline in cross-modal temporal acuity will be associated with changes in audio-visual predictive processing. We expected a difference between younger and older participants' multisensory performance in simultaneity judgement and sound detection tasks. Consistent with this hypothesis, older adults showed a wider temporal window of integration and smaller audio-visual enhancement effect (reflected in increased sound detection rates) compared to younger adults. Based on the current findings, it appears that two different processes mediate audio-visual enhancement: multisensory integration (shorter timescale) and temporal prediction (longer timescale). Older adults' integrative performance was compromised when the stimulus timing was unpredictable and their predictive performance was compromised with relatively rapid audio-visual delays and reduced sound quality. Younger participants did not show comparable effects to the elderly. This explains an increased vulnerability in suboptimal sensory environments among older people, for instance while processing time-compressed speech or while comprehending speech in noisy environments. Potential strategies to enhance sensory performance among older people are suggested.

Date of Award	1 Aug 2016
Original language	English
Awarding Institution	The University of Manchester
Supervisor	Sonja Kotz (Supervisor) & Wael El-Deredy (Supervisor)