Overview

Our interests in human brain function encompass the neural representation of visual and visuospatial information, working memory and action control and the impact of mental and neurological disorders on such representations. We have used fMRI, ERP and eye tracking approaches to examine activity of the prefrontal cortex and other cortical and subcortical areas during tasks requiring working memory maintenance and updating as well as response control.

Current projects

• Neural basis of visual and visuospatial working memory

We use fMRI in conjunction with retro-cue paradigms to investigate neural correlates of task relevant information and the neural fate of no-longer-relevant information. We examine how these representations may vary from lower order to higher order brain regions and how these representations may code multiple memorized items. We also examine individual differences in working memory representation in healthy young adults, children and individuals with major depressive disorder.

Related publication: Jiang L., & Leung, H.-C. (2021) Errors in Visuospatial Working Memory Across Space and Time. Scientific Reports. 11:14449.

Le, T.M., Borghi, J.A., Kujawa, A.J., Klein, D.N., & Leung, H.-C. (2017). Alterations in visual cortical activation and connectivity with prefrontal cortex during working memory updating in major depressive disorder. NeuroImage: Clinical. 14:43-53

• Neural correlates of motor and cognitive control processes in Parkinson’s disease

We have been exploring the neural correlates of individual differences in motor and cognitive symptoms in Parkinson’s disease (PD). We use the stop-signal task during fMRI to investigate whether and how response control is altered in PD at earlier stages. We also use resting-state fMRI to explore the functional brain networks in association with clinical features of PD.

Collaborators: Dr. Guy Schwartz, Stony Brook University Hospital; Dr. Chiang-Shan Ray Li, Yale Medical School

Related publication: Manza, P., Amandola, M., Li, Tatineni, V., C.S., & Leung, H.-C. (2017). Response Inhibition in Parkinson’s Disease: A Meta-Analysis of Dopaminergic Medication and Disease Duration Effects. npj Parkinson’s Disease. 3, 23. doi:10.1038/s41531-017-0024-2.

Manza, P., Schwartz, G., Masson, M., Kann, S., Volkow, N.D., Li, C.R., & Leung, H.-C. (2018) Levodopa improves response inhibition and enhances striatal activation in early-stage Parkinson’s disease. Neurobiol Aging. 66: 12-22.

• Neuroimaging of structure and functional networks

We use both publicly available DTI and fMRI data (e.g., HCP-Aging) and collect our own multimodal data to study the functional and structural relationships between frontal and parietal cortexes. We are interested in delineating the anatomical relationship between these key cortical areas underlying working memory. We also examine whether and how the anatomical tracts such as the superior longitudinal fasciculus relate to the organization of functional networks such as the FPCN and DAN during resting-state and task-state.

Related publication: Amandola M. Katherine Farber, & Leung, H.-C. (2025) Large-Scale High-Resolution Probabilistic Maps of the Human Superior Longitudinal Fasciculus Subdivisions and their Cortical Terminations. Journal of Neuroscience. In press.