Development and Plasticity in Visual Cortex

Date: Saturday, April 8, 2006

Presented by

Brian A. Wandell, PhD

Abstract

Visual cortex has been an excellent model system for developing a quantitative understanding of brain function. We understand a great deal about the physical signals that initiate vision, and this knowledge has led to a relatively advanced understanding of the organization of major structures in visual cortex, such as visual field maps. This talk will explain several measurements and computational methods that are used to understand human brain development and plasticity.

First, we have developed functional magnetic resonance imaging (fMRI) methods for measuring and quantifying the properties of maps in individual human and macaque brains. To understand the development and plasticity of these maps, we have made measurements in several cases of abnormal development as well as in controlled experiments using macaque.

Second, we are combining fMRI with diffusion tensor imaging (DTI), a method that can be used to study the white matter fibers, to understand visual development. Specifically, as children develop and learn to read certain visual recognition skills become highly automatized and the brain develops specialized visual circuitry to support skilled reading. We are measuring how certain parts of these circuits develop, and how the signals from these circuits are transmitted to other cortical systems.

Joint work with Robert Dougherty, Alyssa Brewer, Michal Ben-Shachar, Gayle Deutsch, Stelios Smirnakis and Nikos Logothetis.

Speaker Biography

Dr. Brian A. Wandell is Isaac and Madeline Stein Family Professor at the Psychology Department of Stanford University. His work in visual neuroscience uses both functional MRI and behavior testing to understand the computations of the visual portions of the brain. His team has developed a set of methods for identifying and measuring the signals in several visual areas within the human brain, including regions that respond powerful to motion and color. Recently, his team measured the reorganization of brain function during human development and following brain injury; they are now actively studying the development of visual signals during the age period in which children are learning to read, and changes within cortex that result from retinal dysfunction. In 1986, he won the Troland Research Award from the National Academy of Sciences for his work in color vision. He was made a fellow of the Optical Society of America in 1990 and, in 1997, he became a McKnight Senior Investigator and received the Edridge-Green Medal in Ophthalmology for work in visual neuroscience. In 2000, he was awarded the Macbeth Prize from the Inter-Society Color Council. He was elected to the US National Academy of Sciences in 2003.