Associate Professor of Neuroscience, Johns Hopkins University
Function and development of higher level visual cortex
We are interested in understanding how visual information is transformed between processing stages in visual cortex. Early stages of our visual system represent visual stimuli in a pixel-like fashion, akin to the picture format used by a digital camera. This is a complete, general representation of visual information. However, further processing is required to efficiently store complex visual information, and to carry out the complicated functions accomplished by our visual system. Consider object recognition, for example. Changes in position, color or lighting conditions lead to large changes in the physical appearance of an object, and thereby its pixel-level description. Nonetheless, object recognition is largely invariant to these changes. This is achieved by transforming the initial pixel-level representation into a more invariant and efficient object-level representation. These transformations are implemented in a hierarchy of visual areas.
In general, each processing stage in the visual system transforms its input into a more abstract representation to aid visual perception and cognition. My lab is interested in the structure and function of these circuits, both between primary and higher order visual areas, as well as within individual visual areas. We study how visual information is represented at different processing stages to investigate the nature of the transformations occurring in visual cortex. In addition, we are interested in the development of these circuits and their plasticity. Techniques employed in the lab include two-photon calcium imaging, extracellular recordings, psychophysics, and immunohistochemistry.
Keynote Talk Title & Abstract
The shape of the world – representation of 3D versus 2D shapes in visual area V4