ON THE RELATIONS BETWEEN SEEN OBJECTS AND COMPONENTS OF POTENTIAL ACTIONS

Accounts of visually directed actions usually assume that their planni ng begins with an intention to act. This article describes three exper iments that challenged this view through the use of a stimulus-respons e compatibility paradigm with photographs of common graspable objects as stimuli. Participants had to decide as fast as possible whether eac h object was upright or inverted. Experiments 1 and 2 examined the eff ect of the irrelevant dimension of left-right object orientation on bi manual and unimanual keypress responses. Experiment 3 examined wrist r otation responses to objects requiring either clockwise or anticlockwi se wrist rotations when grasped. The results (a) are consistent with t he view that seen objects automatically potentiate components of the a ctions they afford, (b) show that compatibility effects of an irreleva nt stimulus dimension can be obtained across a wide variety of natural ly occurring stimuli, and (c) support the view that intentions to act operate on already existing motor representations of the possible acti ons in a visual scene.