This project is directed towards understanding the role of the prefrontal cortex (PFC) in modulating category representations in posterior visual association cortex (VAC). The causal effect of PFC modulation on these regions will be tested in patients with focal PFC damage and healthy subjects who have undergone transcranial magnetic stimulation (TMS) of a unilateral PFC region. The ability of these groups to perform a selective attention task that engages category-specific regions of cortex as well as the corresponding pattern of functional magnetic resonance imaging (fMRI) data will provide information about how this top-down modulation occurs. The task used here is designed to segregate the hemispheric responses according to the visual field of presentation. Multiple measures of category selectivity will be applied to the data to assess the hypothesized decrease in selectivity in VAC in the same hemisphere as the PFC impairment. Further, a multivariate analysis of the fMRI data obtained in the two previously described proposed experiments will identify changes in connectivity between the impaired and intact hemispheres.

Public Health Relevance

Basic knowledge about the coupling between PFC and visual cortex gained from this work may be of fundamental clinical significance. A large number of disorders are associated, at least in part, with dysfunction of the frontal lobes. These include psychiatric disorders, such as schizophrenia, attention-deficit hyperactivity disorder (ADHD), obsessive-compulsive disorder, and major depression, as well as a number of structural and degenerative brain diseases including Parkinson's Disease (PD)and Alzheimer's Disease (AD). Knowledge of the role of PFC in top-down modulation may guide development of directed assessments that can refine diagnosis and treatment.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Postdoctoral Individual National Research Service Award (F32)
Project #
1F32EY019618-01
Application #
7677120
Study Section
Special Emphasis Panel (ZRG1-F12A-J (20))
Program Officer
Steinmetz, Michael A
Project Start
2009-05-01
Project End
2011-04-30
Budget Start
2009-05-01
Budget End
2010-04-30
Support Year
1
Fiscal Year
2009
Total Cost
$45,218
Indirect Cost
Name
University of California Berkeley
Department
Neurosciences
Type
Organized Research Units
DUNS #
124726725
City
Berkeley
State
CA
Country
United States
Zip Code
94704
Blumenfeld, Robert S; Nomura, Emi M; Gratton, Caterina et al. (2013) Lateral prefrontal cortex is organized into parallel dorsal and ventral streams along the rostro-caudal axis. Cereb Cortex 23:2457-66
Gratton, Caterina; Nomura, Emi M; Perez, Fernando et al. (2012) Focal brain lesions to critical locations cause widespread disruption of the modular organization of the brain. J Cogn Neurosci 24:1275-85
Nomura, Emi M; Gratton, Caterina; Visser, Renee M et al. (2010) Double dissociation of two cognitive control networks in patients with focal brain lesions. Proc Natl Acad Sci U S A 107:12017-22