Date of Award
Doctor of Philosophy (PhD)
Peripersonal space is the space immediately surrounding one's body. This space is believed to have a unique representation in order to facilitate successful interaction with the surrounding environment. Supporting this theory, there are consistent findings of changes in cognition within as compared to beyond peripersonal space, including differences in visual attention and perception. However, research on peripersonal space in healthy populations has largely focused on young adults. Representations of peripersonal space take place in multimodal brain regions, areas that show structural and functional changes during senescence. Because of this, there is reason to suspect that older adults represent peripersonal space differently than young adults and that this will lead to measurable changes on tasks that rely on those representations. The present experiments used a behavioral approach to examine age differences on three distinct, but related phenomena that rely on peripersonal space representations. Experiment 1 assessed the rate and strength of the rubber hand illusion, a multimodal illusion that primarily occurs when a dummy hand is within the peripersonal space representation of a person's real hand. Experiment 2 measured the perceptual consequences of tool use and the ability to flexibly incorporate a tool into one's peripersonal space representation. Experiment 3 looked at the extent to which attention is automatically biased toward the space near an outstretched hand. Finally, the relationship among the tasks was examined to assess the extent to which the three paradigms are measuring the same construct.
All three experiments showed significant age-related effects. Young adults consistently exhibited changes in performance when performing the tasks within as compared to beyond peripersonal space. Older adults, however, had the same pattern of performance regardless of whether they performed the task within or beyond peripersonal space. Surprisingly, there were no correlations among the experimental measures, suggesting that the selected tasks may be measuring different aspects of peripersonal space. These results have implications for our understanding of mobility and goal-directed action declines in older adults.
Chair and Committee
RIchard A Abrams
David Balota, Denise Head, Joel Myerson, Larry Snyder, Linda Van Dillen
Bloesch, Emily K., "An Investigation into Peripersonal Space Representations in Older Adults" (2013). Arts & Sciences Electronic Theses and Dissertations. 1025.