Use of an occlusion paradigm to examine anticipation of accelerating and decelerating stimuli.

An occlusion paradigm was used to study the effects of intratrial accelerating, decelerating, and constant stimulus velocity on coincidence-anticipation timing. The Bassin anticipation timer was used to occlude the beginning, middle, and end locations of the stimulus traveling to a designated target area. The coincident anticipation responses of 64 college-age participants (32 men; 32 women) were measured for each intratrial stimulus velocity. Analysis of variance indicated a significant main and interaction effect of occluded location by type of intratrial stimulus velocity. Decreasing intratrial stimulus velocity with the beginning and middle of the runway occluded and increasing intratrial velocity with the middle occluded produced the highest error in the participants' coincidence-anticipation accuracy. The contention that more viewing time of the stimulus would result in the lowest coincidence error was not supported for decelerating and accelerating stimulus speeds but was supported for the constant velocity condition. A temporal directional bias was found in both nonoccluded and occluded location conditions which may be due to an assimilation effect.