Perceptual and Attentional Topography of Human Posterior Parietal Cortex

Trustees Of Boston University, Boston

Investigators

Abstract

How do we remember where things are? How do we pay attention to some objects while ignoring distractions? One part of the brain that supports the processing of these and other important functions is the posterior parietal cortex. It is involved in spatial representation, attentional control, planning of eye and hand movements, number sense, and working memory. Despite the importance and diversity of the cognitive functions attributed to this region of the brain, its functional organization is not well understood. Prior studies in non-human primates suggest that this area is comprised of many small cortical areas, each with different functional roles. The goals of this project are: 1) to identify distinct functional subregions of this portion of the human cerebral cortex; 2) reveal the spatial representations that these regions use encode information; 3) reveal the different functional roles that these subregions play in visual attention and visual working memory. With support from the National Science Foundation, Dr. David Somers and colleagues at Boston University will address these questions by seeing the brain at work with functional magnetic resonance imaging. As many as fourteen distinct brain regions, each with a complete map of visual space, can now be identified in individual subjects. Activity within each of these distinct areas will be measured while human volunteers attempt to pay attention to and remember visual stimuli in different situations. This work will reveal a more comprehensive picture of the functional organization of human posterior parietal cortex and of the brain mechanisms that support visual perception, visual attention, and visual working memory. This research also could identify new distinct regions of the cerebral cortex. These investigations have broad implications for the study of neurological diseases and disorders that involve posterior parietal cortex, including Alzheimer's Disease, Williams Syndrome, and a variety of attentional disorders. This research also offers cognitive neuroscience and brain imaging research training opportunities for both undergraduate and graduate students, including those from underrepresented groups.