Research Interests

Human perceptual and cognitive systems show remarkable properties of attunement and calibration to their environment. My doctoral work on simple and contingent aftereffects in the perception of visual texture grew out of a fascination with evidence that the visual system develops coding strategies that optimize information flow and thereby supports action. Perception is a tool, not a product.

Information integration problems got me interested in the perception of shape and depth, where multiple sources of potentially useful information get combined in highly optimised ways. The idea of efficient coding has also informed my work on occlusion and filling in.

More recently my focus has turned to self-motion perception where recalibration processes between vision and action support the highly calibrated activity of walking. The Swarthmore Visual Perception Lab has a large-area virtual reality system where we study how various sources of information regarding self-motion are calibrated, integrated and inter-calibrated. There is a complex interaction between coding in vision and action because perception can be tuned to the contexts of action -- as evidenced by shifts in the perception of visual speed during walking.

My cognitive work is more diverse, but it focuses on how cognitive coding schemes interact with action systems including visual search. What makes information flow efficient and what makes it fail? How do we set up our cognitive systems to optimize the flow of information to planning and action systems that need it?

Students in my lab who are interested in cognition work on a variety of interesting problems including face perception, metaphor and visuo-tactile integration.