Date of Completion

2024

Thesis Type

College of Arts and Science Honors

Department

Department of Psychiatry

First Advisor

Julie Dumas, Ph.D.

Second Advisor

Alicia Ebert, Ph.D.

Keywords

nicotine, visual attention, normal aging

Abstract

Normal cognitive aging is distinct from dementia and Alzheimer’s Disease; however, the different neurobiologies underlying this distinction are not as well understood. It is important to understand the underlying neurobiology of normal cognitive decline because normal cognitive aging affects a large portion of the older adult population and can impact daily tasks by subtly disrupting attention and memory. This project investigated how the nicotinic cholinergic system mediates visual attention in older adults, one cognitive domain that may be affected by healthy cognitive aging. The cholinergic neurotransmitter system mediates visual attention in the brain and disruptions within this system have been implicated in both normal cognitive decline and AD pathologies. Older adults (n=51) ages 65-75 completed an episodic memory task while undergoing fMRI after administration of nicotine. Specific regions, including the prefrontal cortex, parietal cortex, visual cortex, and basal forebrain were analyzed for differences in functional connectivity after nicotine manipulation. The dorsal attention network was also analyzed for differences in functional connectivity. No significant differences were found when comparing drug conditions in the ROI-to-ROI analysis, but a decrease in functional connectivity was found in the functional network analysis of the dorsal attention network. The decrease in functional connectivity in the dorsal attention network after administration of nicotine shows increased functional efficiency and decreased cognitive load required to complete the task.

Download

Available for download on Sunday, May 03, 2026

Share

COinS