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.
- Neurodevelopmental changes in visual information processing in youth
We collected fMRI and behavioral data from a group of 9-12 year old children, who are part of Dr. Klein’s temperament project. We have been examining the relationship between neural activity in the frontal, parietal and medial frontal and parietal regions and children’s performance on a spatial working memory task. We are also exploring the ventral visual pathway and modulatory regions in association with visual information processing in the same children.
Collaborator: Dr. Daniel Klein, Stony Brook University (Visit Dr. Klein’s Lab)
Related publication: Huang, A. S., Klein, D. N., & Leung, H. C. (2016). Load-related brain activation predicts spatial working memory performance in youth aged 9–12 and is associated with executive function at earlier ages. Developmental cognitive neuroscience, 17, 1-9.
- Neural oscillatory and eye-blink correlates of spatial working memory performance
Using EEG and eye-tracking, we have been examining the neural correlates of information control during spatial working memory tasks in young adults. In particular, we have studied neural activity during encoding, maintenance, and updating of task relevant information while ignoring distracting information that is no longer relevant. Another focus has been on the relationship between blinking behavior and working memory performance.
Related publication: Manza, P., Hau, C. L. V., & Leung, H. C. (2014). Alpha power gates relevant information during working memory updating. The Journal of Neuroscience,34(17), 5998-6002.