| Abstract No.: | C-D3138 |
| Country: | Canada |
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| Title: | NORMAL AGING ASSESSED USING SACCADE TASKS WITH FMRI |
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| Authors/Affiliations: | 1 Alicia Peltsch*; 1 Nadia Alahyane; 1 Pat Stroman; 1 Angeles Garcia; 1 Doug Munoz
1 Queen's University, Kingston, ON, Canada
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| Content: | Objectives: Older individuals show decreased voluntary saccade performance. Many cortical changes occur in the aging brain, which influence frontal function. The comparison of pro-saccades (automatically look toward an eccentric stimulus) to anti-saccades (inhibit the automatic saccade to the eccentric stimulus to instead initiate a voluntary saccade away from the stimulus) is often used to investigate frontal function. Our goal is to use functional magnetic resonance imaging (fMRI) to investigate activity patterns of pro- and anti-saccades between younger and older participants to determine how neural correlates of saccade behaviour are altered in the aging brain.
Materials and methods: : Young (age 20-25 yrs) and older (age 63-78 yrs) adults performed an interleaved pro- and anti-saccade task while simultaneous blood oxygen level dependant (BOLD) signal changes were recorded using fMRI. A rapid event-related design including catch trials (no stimulus after instruction) allowed us to separate out saccade preparatory processes from saccade response processes. RESULTS: Preliminary analysis revealed that during the preparatory period, younger adults showed increased BOLD signal changes in oculomotor regions of interest such as the dorsolateral prefrontal cortex, frontal eye fields (FEF), supplementary eye fields (SEF), parietal eye fields (PEF), and caudate in the anti-saccade task relative to the pro-saccade task. In older adults, preparatory activation in the FEF and SEF is attenuated compared to younger adults. These patterns correspond with behavioural performance differences seen between these two age groups.
Conclusion: Normal older adults show decreased frontal recruitment during the preparatory period of the saccade task which may contribute to the altered saccade behaviour in the elderly. These data provide insight into the neural changes occurring during pro- and anti-saccades in the maturing brain and will provide a normative baseline for comparison to neurological disease. |
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