ABSTRACT

An interceptive action can be defined as an externally-directed movement, the trajectory of which is intended to coincide with that of a desired target, which may or not be in motion. In order to successfully intercept an object, perceptual information from the environment needs to be picked up to place the appropriate limb/s at the right place and time, usually while imparting the appropriate amount of force in relation to the object. A wide variety of interceptive actions form essential features of our everyday lives, from pressing a key on a computer, to shaking someone's hand or hitting a ball in a game of squash. Accordingly, researchers working in the field of human movement behaviour have been intrigued by the co-ordination of interceptive actions for some time (e.g. Hubbard and Seng, 1954; Fitts and Posner, 1967; Alderson, Sully and Sully, 1974; Tyldesley and Whiting, 1975; Lee, 1976; Whiting, 1986; Bootsma, 1989). Undoubtedly, interceptive tasks provide a good opportunity to study the complex interaction between human motor control processes and the dynamic environment in which we live (Tresilian, 1999). They provide researchers with an opportunity to investigate how we co-ordinate our movements with the external environment (Turvey, 1990). However, despite the rich source of literature that has considered this group of movements, a complete understanding of the co-ordination processes underpinning interceptive actions remains elusive.