Research Interests
How do we perceive, understand and remember the world around us? The brain’s medial temporal lobe (MTL), including the hippocampus and surrounding cortical regions, is an important hub that supports cognitive representations we use to make sense of the world around us. Since the pioneering work of Milner and Scoville in the 1960s, we have understood that the MTL plays a critical role in declarative memory, but more recent research suggests that it is also involved in perception, language, and other cognitive abilities as well.
Understanding the Cognitive Roles of the Anterolateral Entorhinal Cortex
My research focuses on one specific MTL region, the anterolateral entorhinal cortex (alERC), which serves as the primary connection between the hippocampus and the rest of the brain. While the adjacent posteromedial entorhinal cortex has a well-established role in spatial representation (for which the Nobel Prize in Physiology or Medicine was awarded in 2014), the cognitive roles of the anterolateral entorhinal cortex remains poorly understood. An important aim of my research is to conduct experiments to better understand what the alERC does, and to improve our understanding of how key cognitive processes it supports (e.g. memory, perception, language) are instantiated in the brain. My experimental work has shown that in older adults, alERC integrity is related to differences in visual perception of objects (Yeung et al., 2017) and scenes (Yeung et al., 2019), as well as differences in verbal memory and linguistic fluency (Yeung et al., 2021). Based on its structural connections with the hippocampus and other MTL regions, the alERC may play a role in representing the spatial relations between objects, which supports our ability to remember and differentiate between similar items.
The Anterolateral Entorhinal Cortex in Alzheimer’s Disease
Alzheimer’s disease (AD) is a neurodegenerative disorder that causes progressive cognitive decline, particularly in memory. Biologically, it is characterized by the presence of tau neurofibrillary tangles and amyloid plaques. In humans, AD-related tau aggregates earliest cortically in the transentorhinal cortex, a region that overlaps with the anterolateral entorhinal cortex. These tau aggregates are theorized to represent the early process of neurodegeneration, and are related to subsequent cortical and cognitive changes in AD. Critically, most cases of AD are clinically diagnosed at a much more advanced stage of pathology, suggesting that alERC changes in preclinical older adults might represent the earliest stages of AD. My research aims to quantify how the alERC changes during the preclinical and early stages of AD, how these structural changes are related to other markers of AD pathology (both mechanistically and temporally), and whether alERC changes can predict future progression of AD. My hope is that our understanding of AD-related changes can shed light on the cognitive roles of the alERC, and in turn, our understanding of the alERC’s cognitive roles can be used to develop early detection tests for AD.