Age-Related Changes in Bottom-Up and Top-Down Processing Mediating Object Recognition

Lai, Leslie Yunhsuan

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Year:: 2019
Contributor:: Lai, Leslie Yunhsuan (creator); Heindel, William (Advisor); Festa, Elena (Reader); Song, Joo-Hyun (Reader); Badre, David (Reader); Brown University. Department of Cognitive, Linguistic, and Psychological Sciences (sponsor)
Genre:: theses
Subject:: Visual perception; Cognitive neuroscience; Neurocognitive Aging; Cognitive psychology
Extent:: xv, 199 p.
DOI: https://doi.org/10.26300/vvne-zn63

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Abstract:: Neurocognitive aging is associated with distinct patterns of changes in task-related brain activities in the aging brain. However, the brain mechanisms underpinning such changes are not well understood. This dissertation work presents a novel framework for understanding brain aging within the normal dynamics of bottom-up and top-down processing mediating object recognition. Age-related changes manifest across the entire visual stream affecting multiple visual processes including early sensory processing and cortical feedback mechanisms. In a series of behavioral and electrophysiological experiments, we systematically manipulated stimulus integrity and context congruity within natural scenes to examine age-related changes in the respective bottom-up and top-down effects during object recognition. In the present study, older adults exhibited greater top-down context effect on recognition performance. Our results further suggest that this age-related increase in contextual influence may be attributed to dynamic shifts between bottom-up and top-down processing during object recognition such that older adults engage additional attentional feedbacks and reallocate top-down resources to support compromised bottom-up processing of sensory inputs. Based on the proposed framework and present findings, we argue that the brain mechanism underpinning neurocognitive aging involves the aging brain strategically adopting a new balance between bottom-up and top-down processes to maintain neurocognitive homeostasis.
Notes:: Thesis (Ph. D.)--Brown University, 2019

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Lai, Leslie Yunhsuan, "Age-Related Changes in Bottom-Up and Top-Down Processing Mediating Object Recognition" (2019). Cognitive, Linguistic, and Psychological Sciences Theses and Dissertations. Brown Digital Repository. Brown University Library. https://doi.org/10.26300/vvne-zn63

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Cognitive, Linguistic, and Psychological Sciences Theses and Dissertations

Theses and Dissertations for the Cognitive, Linguistic, and Psychological Sciences department.
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