Workshop on the dynamics of perception and action:
William H. Warren
Department of Cognitive & Linguistic Sciences
Providence, Rhode Island, USA
How are perception and action organized to yield adaptive behavior?
This workshop will discuss the organization of action, the information
available for control, and models of perceptual regulation. We will
review several basic models, including the cognitive approach emphasizing
representation and planning, the cybernetic approach emphasizing
linear closed-loop control, and the dynamical approach emphasizing
stability and nonlinearity. The issue of separate "what/how"
systems for perceptual recognition and visually controlled action
will also be raised. We will discuss the organization of locomotion
in the form of stable gaits and gait transitions, with free parameters
for regulation. The information available in optic flow for locomotion
and interception (e.g. catching) will be examined in some depth,
including a hands-on computer demonstration of flow patterns.
I will bring these threads together by developing the view that
adaptive behavior emerges from the interaction between an organized
agent and a structured environment, represented as a pair of coupled
dynamical systems. On this view, action is a function of information,
according to laws of control, and reciprocally, information
is a function of action, according to laws of ecological optics.
The resulting behavior corresponds to attractors in the dynamics
of the coupled system. Thus, to understand how perception and action
produce adaptive behavior, the task is to characterize the system-level
dynamics and show how the coupling laws give rise to them. Several
case studies will be presented, including infant bouncing in a "jolly
jumper," visually controlled braking, and walking to a goal.
This view suggests that, rather than acting like a centralized controller,
the nervous system exploits informational and physical regularities
to stabilize the dynamics of the agent-environment system.