NEURAL RESPONSES TO NARRATIVE EVENT BOUNDARIES IN EARLY ALZHEIMER'S DISEASE

Alzheimer’s Disease (AD) is typically associated with symptoms such as memory impairments and spatial disorientation. However, a growing body of evidence points towards impairments not just in spatial, but temporal episodic memory, such as the memory for the temporal order, position and distance of events. One aspect of these impairments might be deficits in event-segmentation, the process whereby we parse our continuous stream of experiences into separate representations in memory. Indeed, ongoing work suggests significant differences in the perception of event boundaries between participants with early Alzheimer's Disease (EAD) and age matched controls.
To clarify the underlying neural mechanisms, the current study aims to contrast in neural activity at narrative event boundaries between participants with early Alzheimer's Disease and age-matched controls, focusing on relevant areas in the medial temporal lobe (MTL) and posterior medial cortex (PMC).
We presented participants with EAD and age-matched controls with an auditory narrative, while recording their brain activity using fMRI. A separate group of young participants was asked to segment the same story into events by marking event boundaries. Using the event boundary timepoints derived from this group, we compared the brain activity between participants with EAD and the age-matched controls. Additionally, we acquired different biomarkers, such as CSF p-tau and Amyloid beta status from participants with EAD and age-matched controls.