PERCEPTUAL AND MOTOR PROCESSES IN INTERCEPTIVE TIMING

Precise timing of interceptive actions appears to be based on perceptu ally derived time-to-contact (T(c)) information. Two questions are con sidered. First, ''What are the perceptual processes involved in extrac ting T(c) information from sensory stimulation?'' A preliminary answer is provided in the form of an account of the functional organisation of the perceptual process based on work on information integration. Th is account is used to interpret in a unified manner a number of recent empirical and theoretical results. Second, ''How is T(c) information used to control interceptive timing?'' Problems of how to use perceptu al information are identified. Solutions to some of these are examined through development of a model of continuous control of movement in a ball-punching task studied by Lee and colleagues. The model is based on the equilibrium point hypothesis for motor control (Feldman, 1986) and illustrates how perceptual information can determine muscle forces and movement kinematics.