William H. Warren Chancellor's Professor of Cognitive, Linguistic, and Psychological Sciences

My research focuses on the visual control of action - in particular, human locomotion and navigation. On the one hand, I want to understand how motor behavior such as posture and gait become stably organized. On the other, I seek to explain how this behavior is adaptively regulated by visual information in complex environments. Using virtual reality techniques, my research team investigates problems such as the visual control of balance, steering, and obstacle avoidance during walking. This technology allows us to manipulate what human subjects see while walking through the virtual landscape, and to measure how they respond to this information. By using computer graphics, we test how the visual system determines one's future path of self-motion from information such as optic flow, in order to characterize the functions that the brain must perform. The ultimate aim of this research is to understand how adaptive behavior emerges from the dynamic interaction of an organism and its environment. I think the answers will not be found solely in the brain, but will also depend on the physical and informational regularities that the brain comes to exploit. This research contributes to a foundation of basic knowledge that is needed to understand visual-motor disorders and mobility problems in humans, and to develop mobile robots that can operate in novel environments such as the surface of Mars.


I became interested in this research as a doctoral candidate in experimental psychology at the University of Connecticut when it became clear to me that the function of vision is to control behavior. Early perceptual experiments led to my current interest in the link between vision and action.

Brown Affiliations

Research Areas

research overview

Bill Warren takes an ecological approach to problems of perception and action, which aims to see how much of the organization in behavior can be explained "for free" on the basis of informational and physical constraints in natural environments. His current research focuses on the visual content of locomotion.

research statement

Bill Warren takes an ecological approach to problems of perception and action, which aims to see how much of the organization in behavior can be explained "for free" on the basis of informational and physical constraints in natural environments. His current research focuses on the visual content of locomotion and investigates the following questions: First, how do we perceive self-motion from patterns of optic flow? Computer displays that simulate motion through the world are manipulated to understand how the visual system determines one's path of self-motion. Second, what are the visual control laws that govern human walking? Using a large Virtual Reality (VR) Lab (40' x 40'), experiments examine the on-line control of balance, braking, steering, obstacle avoidance, and route selection in a world of stationary and moving objects. Third, how might such principles be extended to longer-range navigation? A collaborative project with Michael Tarr and Leslie Kaebling uses the VR lab to study visual navigation and "cognitive maps" in humans and mobile robots. Finally, how can control problems be simplified by exploiting the dynamics of the system? Experiments on this problem examine critical behavior near gait transitions, mode-locking between gait and posture, the dynamics of steering control, and stable behavior in infant bouncing. The ultimate aim of Dr. Warren's research is a dynamic theory of adaptive visual control.

funded research

(a) Current grants

National Science Foundation (NSF), "Dynamics of action and perception in a rhythmic task," 2005-08, Co-PI (with Dagmar Sternad), $283,725.
National Institutes of Health (NIH), "Visual control of locomotion." 2003-2008, PI, $1,241,290.
NSF, "Learning minimal representations for visual navigation and recognition." 2003-07, Co-PI (with Michael Tarr), $324,714.
NSF/Information Technology Research (ITR), "Understanding unsteady bioflows through simulation, modeling, visualization, art, and psychology." 2005-09, Co-PI (with Laidlaw, et al.), $650,000
NSF/Integrative Graduate Education and Research Traineeship (IGERT) Training Grant, "Dealing with uncertainty: Cognitive, computational, and statistical approaches." 1998-06, participating faculty (with Johnson, et al).
NIH, "Variability and stability in skill acquisition." 2003-06. Consultant (for Dagmar Sternad, Pennsylvania State University).

(b) Completed grants

NIH, "Age-related changes in the visual control of locomotion." 1985-88, PI, $240,000.
NIH, "Visual control of locomotion." 1989-94, PI, $500,000.
NIH, "Visual control of locomotion." 1994-98, PI, $675,000.
National Institute of Mental Health (NIMH) Research Career Development Award, "Visual control of adaptive behavior." 1997-02, PI, $500,000.
NSF, "Learning minimal representations for visual navigation." 1997-01, Co-PI (with Tarr and Kaelbling), $825,000.
NIH, "Visual control of locomotion." 1998-03, PI, $830,222.
NSF, "Visualization of Multi-Valued Scientific Data." 2000-03, Co-PI (with Laidlaw, et al.), $2,296,599.
NIH, "The effects of lesions on visual motion perception in humans." 2001-04, Consultant (for Lucia Vaina, Boston University).