EFFECTS OF SPATIAL AND TEMPORAL CONSTRAINTS ON INTERCEPTIVE AIMING TASK PERFORMANCE AND GAZE CONTROL.

The perceptual process of obtaining and using visual information plays a critical role in determining the quality of interception performance. Eye-movement characteristics and their association with interception accuracy where the constraints imposed on the task influence the eye-movement control are not well understood. The effects of spatial and temporal constraints were examined and associated with target motion on interception accuracy and gaze control strategy. Twenty-four (M = 28 yr., SD = 10; 10 women) inexperienced dart throwers volunteered for the study. Eye movements were measured while the participants attempted to intercept a horizontally moving target with a thrown dart. A mixed design experiment was employed with a between- (specification of interception point) and a within- (target speed) subjects factor. As target speed increased, spatial errors about the moving target increased but temporal errors decreased. Specifying a fixed location for target interception resulted in greater errors about the moving target. The point of gaze tended to center on the interception point, and this became more evident with increased target speed and the specification of a fixed interception point. The experimental findings provide support for a visual search strategy that exhibits compliance with the constraints of the task.