Time to contact as a determiner of action: Vision and motor control

This chapter examines the role vision—the “time to contact” variable. The notion of direct perception is used. The role of vision in mediating information in tasks, such as stabilizing the head and eyes, maintaining balance, steering, and locomotion are of major significance. The importance placed on movement in perception is something that simply can no longer be ignored; visual perception and plans for voluntary action are so intimately bound together that they may be considered as products of one cerebral function. Direct perceptionists would argue about the ‘richness of light,’ and how light carries information about the environment through which it has travelled and from which it has been reflected. In the motor domain, actions are too often studied separately from both perception and the environment in which the actions are carried out. Ecological psychology advocates concepts and tentative mechanisms by which this interactive process may came out at least at the perceptual and environmental levels.