BME PhD Proposal Seminar: Adam Bosen
The Effect of Aging on Audiovisual Binding and Adaptation
Supervised by Dr. Gary Paige and Dr. William OâNeill
As humans advance in age, they undergo a number of sensory changes that adversely affect quality of life. Aging increases the likelihood of visual and hearing impairments, which lead to a subsequent loss of quality of life and an increase in fall risk and mortality. Vision and hearing are of particular importance because they fulfill complementary roles in perceiving and understanding the surrounding environment. Vision provides precise spatial and limited temporal information from a restricted field in front of an individual, while hearing provides precise temporal and less reliable spatial information about the entire space around an individual. In order to fully utilize both senses, individuals must integrate this information to form a coherent interpretation of their environment. Integrating signals from multiple senses hinges on the ability to map information from one sense to another, so that an individual can decide which, if any, visual and auditory signals originate from a common source and should be combined.
The process of combining signals from multiple senses is known as binding, and produces a percept that is more precise (reduced variance) than a percept formed from auditory or visual signals alone. Additionally, the mapping of one sense to another can be changed by repeated exposure to a constant spatial or temporal disparity between audiovisual signals, a process known as adaptation. Perceptual precision and sensation-related cortical activity tend to degrade as adults age, so it is hypothesized that elderly adults will bind and adapt to audiovisual stimuli in a manner that is distinct from young adults. However, age-related differences in binding and adaptation have never been studied, so it is unknown what elderly adults perceive when presented with auditory and visual signals and how their perception differs from that of young adults. The specific aims of this research are to:
- Characterize age-dependent differences in spatial and temporal audiovisual binding.
- Characterize age-dependent differences in audiovisual alignment adaptation.
It is expected that elderly adults will show differences in distinguishing spatially or temporally separated audiovisual events when compared to young adults, which subsequently alters alignment adaptation and ability to maintain congruence between the senses.