Multisensory Integrative Processes and Aging

Abstract

Our sensory systems provide us with distinct impressions of our surroundings which are critical for perception, cognitive processing, and control of action. Indeed, input from multiple sensory stimuli compared to a single sensory stimulus increases the likelihood of detection, sensitivity, and the likelihood of correctly identifying the event. However, this process changes as we age. In this dissertation, I investigate the changes associated with auditory and visual integration in older adults by utilizing various psychophysical tasks. This dissertation aims to determine the following: (1) to understand the relation between behavioural tasks that are commonly utilized to investigate multisensory integration, (2) to investigate how performance on these tasks changes when the central nervous system is aroused or stressed through the use of exercise (both in-person and virtually), and (3) to investigate the limitations and shortcomings of the current practices in the multisensory integration literature. Results indicate that older adults are impaired in judging temporal order of events, however they also exhibit greater performance gains in response time to multisensory, compared to uni-sensory stimuli. Further, results reveal that the integration process is malleable and thus physical activity, both in-person and virtually, may be a useful intervention that can help to improve the speed, accuracy, and precision with which older adults integrate multisensory information. A scoping review concludes the dissertation, which reveals that only 60% and 50% of studies measure for age-abnormal hearing and vision respectively and that within these studies a consistent definition of what constitutes normal hearing and vision is not found.