Visual occlusion factors in a discrete ball-catching task.

Male university students (N=44) attempted to catch lawn-tennis balls delivered by a mechanical projection machine. The ball was always projected in the dark and caught in the dark but was illuminated for a constant, brief interval during its flight by a fluorescent tube. The portion of flight illuminated was varied by manipulating systematically the interval between light offset and ball-hand contact. This variable served as the single factor in a within-Ss design. ANOVA showed that catching success was reliably dependent upon this variable and related to it by an inverted 'U' function. Results were discussed in terms of prediction ability and a possible limitation in information processing time.