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.
