Aging and Cognitive Control: Hemispheric Differences and White Matter Integrity
Leaver, Echo E.
This item is only available for download by members of the University of Illinois community. Students, faculty, and staff at the U of I may log in with your NetID and password to view the item. If you are trying to access an Illinois-restricted dissertation or thesis, you can request a copy through your library's Inter-Library Loan office or purchase a copy directly from ProQuest.
Permalink
https://hdl.handle.net/2142/82162
Description
Title
Aging and Cognitive Control: Hemispheric Differences and White Matter Integrity
Author(s)
Leaver, Echo E.
Issue Date
2008
Doctoral Committee Chair(s)
Fabiani, Monica
Department of Study
Psychology
Discipline
Psychology
Degree Granting Institution
University of Illinois at Urbana-Champaign
Degree Name
Ph.D.
Degree Level
Dissertation
Keyword(s)
Psychology, Psychobiology
Language
eng
Abstract
"The ability to flexibly control cognitive processed declines with aging. Age-related changes in cognitive control have been associated with white matter as well as gray matter decline. Specifically, it has been established that anterior regions of the corpus callosum (aCC) decline with advanced age. This decline in aCC may lead to a reduction in the ability of the pre-frontal cortices to coordinate their activity and successfully engage in top-down control of posterior regions. Thus, the decline in cognitive control observed in aging can be said to result from ""cortical disconnection."" However, it has also been suggested that the right hemisphere (RH) ages more quickly than the left hemisphere. This would indicate that older adults would have more impairment in RH tasks. The current study explored the relative contributions of these two mechanisms in cognitive changes in aging. Electrophysiological (ERP) data were recorded from 48 subjects who were divided into 4 groups (young with large aCC, young with small aCC, old with large aCC, old with small aCC). ERP data was collected while participants engaged in a task in which they were required to switch between processing global and local aspects of congruent and incongruent stimuli. The presentation of a precue informed them on which aspect (global or local) of the following imperative stimulus to focus on. Behavioral data revealed the predicted main effects for all subjects: decreased accuracy and longer reaction times on local, incongruent, and switch trials. Behavioral and ERP data indicated that decline in aCC and in right hemisphere function play important roles in age-related changes in cognitive control."
Use this login method if you
don't
have an
@illinois.edu
email address.
(Oops, I do have one)
IDEALS migrated to a new platform on June 23, 2022. If you created
your account prior to this date, you will have to reset your password
using the forgot-password link below.
