Highlights from Select Research Projects
Individual differences in sulcal morphology in aging and Alzheimer's disease (AD)
Recent work suggests that the sulci (folds) of the cortex are uniquely vulnerable to atrophy and pathology in aging and AD. However, these studies focus only on the largest, deepest, and most consistent sulci across individuals. Tertiary sulci — the smallest, shallowest, and most individually-variable indentations — have been associated with the development of human-specific aspects of cognition and with symptoms of diseases such as schizophrenia and frontotemporal dementia, but have not been investigated in normal aging or AD. In this project, we investigate relationships between individual differences in sulcal morphology (including tertiary sulci) and cognitive and pathological changes in aging and AD.
Publications:
- Maboudian SA, Willbrand EH, Kelly JP, Jagust WJ, Weiner KS. Defining overlooked structures reveals new associations between cortex and cognition in aging and Alzheimer’s disease. J Neurosci. 2024; 44(16):e1714232024
Tertiary sulci in evolution and disorder
Traditional neuroanatomy studies have largely overlooked tertiary sulci — the smallest, shallowest, and most individually-variable folds in the brain. These variable sulci are the evolutionarily-newest and latest-developing cortical indentations, and recent work suggests their development is in turn related to the development of various higher-order cognitive functions (e.g., reasoning) and neuropsychiatric disorders. This series of projects seeks to improve our understanding of the evolution of these structures and the relationships between their morphology and neuropsychiatric symptoms.
Publications:
- Willbrand EH*, Maboudian SA*, Kelly JP, Parker BJ, Foster B, Weiner KS. Sulcal morphology of posteromedial cortex substantially differs between humans and chimpanzees. Commun biol. 2023; 6(1), 586
- Willbrand EH, Maboudian SA, Kellerman GK, Elliott MV, Johnson SL, Weiner KS. Variable presence of an evolutionarily new brain structure is related to a transdiagnostic predictor of psychopathology. (Submitted)
- Kelly JP, Willbrand EH, Chen X, Maboudian SA, Parker BJ, Jiahui G, Garrido L, Zhen S, Duchaine B, Weiner KS. Overlooked sulci in human posteromedial cortex are related to face processing. (Submitted)
- Hastings III WL, Willbrand EH, Elliott MV, Kelly JP, Maboudian SA, Johnson SL, Weiner KS. Emotion-related impulsivity is related to orbitofrontal cortical sulcation. (Under review)
Contributions of memory to decision-making impairments in dementia
The decisions we make are often open-ended, relying on options we generate ourselves. Classical decision-making models do not consider this aspect of decision-making, but more recent work seeks to establish an updated framework linking memory retrieval and valuation processes to better reflect real-world decision-making. This project involves applying these updated models to investigating decision-making changes in aging and dementia.
Publications:
- Zhang Z, Maboudian SA, Jackson A, Ngo S, Manivannan M, Kayser AS, Hsu M, Chiong W. Mechanistic contributions of memory to decision-making impairments in Alzheimer’s disease. (in prep)
- Kayser A, Zhang Z, Maboudian S, Jackson A, Ngo S, Chiong W, Hsu M. Open-ended, value-based decision making requires semantic memory: a computational, imaging, and clinical study (P1-6.005) [abstract]. Neurology. 2022;98(18 Supplement):534.