The effects of age on the neural correlates of episodic memory encoding and retrieval

My research examines how age-related changes in the specificity and organization of neural representations contribute to episodic memory decline. In early work, I showed that neural differentiation is reduced with age particularly in the scene-selective cortex, and that greater selectivity in these areas predict better subsequent memory performance across age groups. In subsequent work, I demonstrated that brain regions that exhibit age-related neural dedifferentiation extend beyond the scene-selective cortex when operationalized at different levels of analysis. Moreover, using simultaneous fMRI and eye-tracking, I demonstrated that age differences in scene selectivity may arise due to alterations in exploratory eye-movement behaviors during scene viewing.

A second strand of my work examines age differences in the neural mechanisms supporting episodic retrieval. I have demonstrated that older adults show a reduced ability to selectively reinstate information according to current retrieval goals, consistent with an age-related decline in retrieval gating. Expanding this work, I showed that the spatial distribution of category-selective activity shifts anteriorly from encoding to retrieval within ventral visual cortex, and that this retrieval-related anterior shift is exaggerated in older adults. Critically, larger shifts were associated with poorer episodic memory performance, suggesting that the effect may reflect a transformation from perceptually detailed representations at encoding toward more gist-based or abstracted representations during retrieval.

The effects of age on spatial memory and navigation

Spatial disorientation and navigation difficulties can have important consequences for independence in older adulthood. My research examines the cognitive and neural mechanisms underlying age-related differences in spatial memory, with a particular focus on how spatial representations are affected by changes in viewpoint and movement through the environment.

Using immersive virtual reality and computational modeling, I examine how visual and self-motion cues shape spatial memory behavior across age groups and which underlying decision processes contribute to these effects. Complementing this work, my fMRI research investigates how aging alters neural representations of spatial environments across repeated and transformed viewpoints. This work has shown age differences in repetition-related responses within scene-selective cortex and broader posterior visual and medial temporal regions, providing a neural account of how spatial representations change with age.

The neurobiological mechanisms underlying individual differences in cognitive aging

More recently, my research has expanded to examine neurobiological sources of individual differences in cognitive aging. I focus on the locus coeruleus, a brainstem nucleus that provides the primary source of cortical norepinephrine and is among the earliest sites of Alzheimer’s-related tau pathology. Using high-resolution magnetization-transfer MRI, advanced diffusion imaging, and functional MRI, I am beginning to test whether individual differences in locus coeruleus structure and microstructure are associated with neural specificity and memory performance in older adulthood.

This emerging line of work also examines how MRI-based measures of locus coeruleus integrity relate to cognitive and blood-based biomarkers associated with preclinical Alzheimer’s disease. More broadly, I am interested in using multimodal imaging to clarify the biological mechanisms that link brain aging to variability in cognition.