Precise timing when hitting falling balls.

Eli Brenner,Ben Driesen,Jeroen B J Smeets

doi:10.3389/fnhum.2014.00342

Abstract

People are extremely good at hitting falling balls with a baseball bat. Despite the ball's constant acceleration, they have been reported to time hits with a standard deviation of only about 7 ms. To examine how people achieve such precision, we compared performance when there were no added restrictions, with performance when looking with one eye, when vision was blurred, and when various parts of the ball's trajectory were hidden from view. We also examined how the size of the ball and varying the height from which it was dropped influenced temporal precision. Temporal precision did not become worse when vision was blurred, when the ball was smaller, or when balls falling from different heights were randomly interleaved. The disadvantage of closing one eye did not exceed expectations from removing one of two independent estimates. Precision was higher for slower balls, but only if the ball being slower meant that one saw it longer before the hit. It was particularly important to see the ball while swinging the bat. Together, these findings suggest that people time their hits so precisely by using the changing elevation throughout the swing to adjust the bat's movement to that of the ball.

Highlights

People are extremely good at intercepting a falling ball with a bat (McLeod et al, 1985; Brenner et al, 2012)
Performance in the blurred and small ball conditions was very similar to the baseline performance, but performance in the monocular condition looks a bit poorer. This could be considered to suggest that binocular vision is critical for interception, but that our study does not have enough power to demonstrate this, we do not interpret it in that manner, because closing one eye does remove purely binocular information (Rose, 1978; van Mierlo et al, 2011)
We found that temporal precision is not limited by the retinal resolution for judging size

Summary

Introduction

People are extremely good at intercepting a falling ball with a bat (McLeod et al, 1985; Brenner et al, 2012) They can time their attempts to hit a ball with a precision of about 7 ms (we use the standard deviation as our measure of temporal precision throughout this article). This is much better than the temporal precision in indicating which of two targets stopped moving first (27 ms at best; Figure 3C of Tadin et al, 2010) or changed length first (35 ms at best; Figure 5 of Baruch et al, 2013). Temporal precision is only less than 7 ms for judging which of two adjacent targets was flashed first (Figure 1 of Westheimer and McKee, 1977a), in which case the temporal order is presumably judged from the perceived motion (Brenner and Smeets, 2010)

Methods

Results

Conclusion