Abstract
Alzheimer’s disease (AD) is characterized by a steep decline in the recall of recent memories and events. It has previously been shown that elevated levels of intracellular tau-containing tangles (tau) are associated with greater risks of AD-related memory deficits. Prior research has additionally found a link between the poorer recall capabilities due to tau burden and the posterior medial (PM) network of the temporal lobe. To investigate this network, prior research has utilized task-based fMRI, but due to task challenge and adherence, many AD patients find this form of testing to be too difficult. This thesis aims to address this gap by proposing the use of movie-watching and fMRI synchrony to investigate the PM network’s association with tau. fMRI intersubject synchrony provides a way to measure the similarity in fMRI patterns across the span of an event, allowing one to measure how a participant’s activity within the PM network matches up with the average participant’s activity in the network. Cognitively unimpaired older adults were played three films while in the fMRI scanner and afterwards were asked to recall what occurred in each film. Additionally, each participant’s tau burden was measured via [18F]MK-6240 PET imaging to get a metric on their degree of tau accumulation. Results found no significant findings that suggested that a participants’ fMRI synchrony within the PM network was associated with the recall of each film, nor was associated with the degree of tau accumulation within the temporal lobe. These results suggest that further research may need to be completed to determine future methodologies for investigating the associations between the PM network and Alzheimer’s disease.