Research

We are interested in understanding how visual information is transformed between processing stages in visual cortex. Early stages of our visual system like the retina represent visual stimuli in a pixel-like fashion, akin to the picture format used by a digital camera. This is a complete, but inefficient representation of visual information. Further processing is required to transform visual information into a more efficient and compact form, and to support 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, due to transformations of visual information implemented in higher-level 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-level 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 how these circuits develop, and their plasticity in the adult brain. Techniques employed in the lab include two-photon calcium imaging, extracellular recordings, psychophysics, and immunohistochemistry.

The lab is part of the Solomon Snyder Department of Neuroscience. We closely collaborate with the lab of Ed Connor on studies of higher level visual processing. We also collaborate with other labs at Johns Hopkins to investigate further aspects of visual processing and brain development. Current collaborations include investigations of the impact of cross-modal plasticity on primary visual cortex (with Hey-Kyoung Lee’s lab), the role of somatosensory cortex in non-rodent species (with Dan O’Connor) and the importance of different progenitors for the development of the neocortex in larger mammals (with Uli Mueller’s lab). We are also part of an NSF funded NeuroNex consortium aimed at developing and distributing new two-photon technology.