Overview of my PhD Research Program
Perceptual organization entails processes that integrate basic stimulus elements into a Gestalt (translated by some as "the whole"). Ongoing research continues to uncover the principles by which low-level stimulus features are grouped together, and how the foreground becomes perceptually segregated from the background, which are essential processes underlying higher order perception.
Late adulthood is associated with not only changes the anatomy of the eye, but is also correlated with changes to the brain that processes visual information. Over my PhD, I explored the effects of aging on figure-ground (FG) perceptual organization, and grappled with the question: how does the aging brain impact individuals' ability to segregate figures from the surrounding backgrounds?
Over a number of experiments, we found an age difference in FG perception consistent with reduced cortical inhibition observed in aging. Our work also indicated a neural signature in the electrophysiological evoked response associated with behavioural performance in the FG task. Overall, the findings suggest that younger adults can resolve higher competition between perceptual interpretations of our stimuli by altering processing mechanisms underlying FG organization. Older adults, who appear to have more trouble resolving resolving the high competition, do not seem to be altering those same processing mechanisms.
The age differences in perceptual organization found in our work are consistent with other findings that high ambiguity stimuli pose particular challenges to the aging visual system. Such findings are crucial in the effort to characterize the challenges faced by senior citizens. Exploring these types of questions is critical as we work towards develop solutions that improve functioning and longevity in this growing portion of the population.
My full PhD dissertation can be downloaded below: