My graduate training will use working memory (WM) as a model to study the function of the frontal lobes.Frontal lobe syndrome (FLS) describes a set of symptoms that is characterized by a variety of behavioral and neurological deficiencies. For more accurate diagnosis and to understand the symptoms, an understanding of the basic functions of the frontal lobes is required. WM, which refers to the ability to maintain and manipulate an item in consciousness for a short period of time, is an ability that is known to be disrupted in FLS and may account for many of its symptoms. Current models of WM are in disagreement on the function of the frontal lobes. For my first study I will use repetitive transcranial magnetic stimulation (rTMS), a tool that temporarily disrupts processing in a specific brain area in normal human subjects, to investigate the role of the frontal lobes and other brain areas in WM. The effect on performance of rTMS applied to these brain areas during different types of WM tasks will allow for isolation of the specific role of each brain area in WM. My second study will involve the use of phase-encoded functional magnetic resonance imaging to create retinotopic maps related to spatial WM. This technique uses regularly rotating stimuli to find areas of the brain that are sensitive to the location of the item that is being stored in WM. I hope to learn about the relationship between spatial attention and spatial WM in the frontal lobes. Along with my medical education, my goal is to use my experience with this project to be able to apply the techniques used in cognitive neuroscience research to diagnosis and treatment in the clinical setting. My proposed research will investigate the role of several frontal and posterior brain regions in working memory storage and memory-guided action. This will not only shed light on how working memory works, but will also reveal information about the specific deficits that patients with frontal lobe damage or degeneration may have. Knowledge of which abilities are disrupted in patients with frontal lobe damage may also allow for development of rehabilitation techniques which would bypass the use of the damaged cognitive processes.

Agency
National Institute of Health (NIH)
Institute
National Institute of Mental Health (NIMH)
Type
Individual Predoctoral NRSA for M.D./Ph.D. Fellowships (ADAMHA) (F30)
Project #
5F30MH078705-03
Application #
7679026
Study Section
Special Emphasis Panel (ZRG1-F12A-D (20))
Program Officer
Desmond, Nancy L
Project Start
2007-09-28
Project End
2012-09-27
Budget Start
2009-09-28
Budget End
2010-09-27
Support Year
3
Fiscal Year
2009
Total Cost
$41,176
Indirect Cost
Name
University of Wisconsin Madison
Department
Psychology
Type
Schools of Arts and Sciences
DUNS #
161202122
City
Madison
State
WI
Country
United States
Zip Code
53715
Hamidi, Massihullah; Johson, Jeffrey S; Feredoes, Eva et al. (2011) Does high-frequency repetitive transcranial magnetic stimulation produce residual and/or cumulative effects within an experimental session? Brain Topogr 23:355-67
Hamidi, Massihullah; Slagter, Heleen A; Tononi, Giulio et al. (2010) Brain responses evoked by high-frequency repetitive transcranial magnetic stimulation: an event-related potential study. Brain Stimul 3:2-14
Johnson, Jeffrey S; Hamidi, Massihullah; Postle, Bradley R (2010) Using EEG to explore how rTMS produces its effects on behavior. Brain Topogr 22:281-93
Hamidi, Massihullah; Tononi, Giulio; Postle, Bradley R (2009) Evaluating the role of prefrontal and parietal cortices in memory-guided response with repetitive transcranial magnetic stimulation. Neuropsychologia 47:295-302
Hamidi, Massihullah; Tononi, Giulio; Postle, Bradley R (2008) Evaluating frontal and parietal contributions to spatial working memory with repetitive transcranial magnetic stimulation. Brain Res 1230:202-10