Effects of Same-Speed Stimulus Trial Length on Coincidence Anticipation

Purpose

The purpose of this study was to determine the degree of temporal bias between slow and fast stimulus trials when preceded by different lengths of consecutive same-stimulus speed trials.

Methods

Sixteen subjects ages 18-24 with 20/20 vision or corrected 20/20 vision with normal contrast sensitivity voluntarily participated in the study. Each subject's dynamic visual acuity threshold was established to determined the velocity at which the subject can maximally visually track a moving object. Dynamic visual acuity threshold velocity was then used to determine each subject's fast and slow velocity (+/- 4 mph) trials. The subject's coincidence anticipation timing performance was assessed across 240 trials to determine the degree of the temporal bias effect involving different number of the same speed trials (1-5) followed by a slow or fast speed trial.

Analysis/Results

The results revealed that a temporal bias effect was significant when subjects were presented a fast or slow change in stimulus speed (F1, 4=72.9, p=<.001). The length of same-stimulus speed trials, 1 to 5 successive trials, had no influence on the degree of one's coincidence anticipation temporal timing biases (F1, 4= .142, p=.96).

Conclusions

A slow stimulus following a series of same-stimulus speed trials caused one to underestimate the moment when the object will arrive to the target area, whereas with a fast stimulus one seems to overestimate. This temporal bias effect found in this study supported previous research findings. Length of same-speed stimulus trials preceding a slow or fast stimulus did not affect the degree of the temporal bias. The temporal bias demonstrated by the participants in this study may be due to immediate speed changes between stimulus trials and not the number or length of preceding same-speed stimulus trials.