Multisensory integration of peripherally presented audiovisual stimuli in older adults: An event-related potential study

Alzheimer's disease (AD) is the most common form of dementia among older people. The number of dementia is increasing rapidly with appearing phenomenon of aging. A previous study showed that brain glucose metabolism was different with that between healthy people and Alzheimer patients during the response to passive audiovisual stimulation. In the present study, we designed a discrimination task that unimodal visual stimuli, unimodal auditory stimuli and bimodal audiovisual stimuli were randomly presented left or right side of screen and investigated the multisensory integration of peripherally presented audiovisual stimuli in older adults using Event-Related Potential. Two periods of significant interactions were found: the right occipital area at 160-200 ms after the presentation of the stimulus and the left fronto-central area at 300-600 ms after the presentation of the stimulus. Our results identified multisensory integration brain activities in the healthy older adults. In next study, we will discuss audiovisual integration for patients with Alzheimer's disease using experiment design of this study, and hope to find out an excellent method for Alzheimer's disease early detection.