Keeping Your Eyes Continuously on the Ball While Running for Catchable and Uncatchable Fly Balls

Abstract

When faced with a fly ball approaching along the sagittal plane, fielders need information for the control of their running to the interception location. This information could be available in the initial part of the ball trajectory, such that the interception location can be predicted from its initial conditions. Alternatively, such predictive information is not available, and running to the interception location involves continuous visual guidance. The latter type of control would predict that fielders keep looking at the approaching ball for most of its flight, whereas the former type of control would fit with looking at the ball during the early part of the ball's flight; keeping the eyes on the ball during the remainder of its trajectory would not be necessary when the interception location can be inferred from the first part of the ball trajectory. The present contribution studied visual tracking of approaching fly balls. Participants were equipped with a mobile eye tracker. They were confronted with tennis balls approaching from about 20 m, and projected in such a way that some balls were catchable and others were not. In all situations, participants almost exclusively tracked the ball with their gaze until just before the catch or until they indicated that a ball was uncatchable. This continuous tracking of the ball, even when running close to their maximum speeds, suggests that participants employed continuous visual control rather than running to an interception location known from looking at the early part of the ball flight.

The visual control of interceptive steering: How do people steer a car to intercept a moving target?

“…During interception, subjects tracked visible targets with smooth pursuit eye movements most of the time as reflected by the small gaze-target angle. This is consistent with previous studies on locomotor interception (e.g., Oudejans et al, 1999;Postma et al, 2014). Similarly, in accordance with previous studies (e.g., Land & Lee, 1994), gaze behavior and steering behavior were coordinated.…”

“…It has been shown that actors' gaze is predominantly anchored on the target during both manual interception (e.g., Brenner & Smeets, 2011;Cesqui, Mezzetti, Lacquaniti, & d'Avella, 2015;Lopez-Moliner & Brenner, 2016) and locomotor interception (e.g., McBeath, Shaffer, & Kaiser, 1995;Oudejans, Michaels, Bakker, & Davids, 1999;McLeod, Reed, & Dienes, 2006;Postma, den Otter, & Zaal, 2014). Specifically, to catch a fly ball in a short duration between 1.8 and 2.5 s, actors visually track the ball most of the time (Oudejans et al, 1999;Postma et al, 2014). Interestingly, a recent study in highly trained cricket players has suggested that batters coupled the rotation of their head to the movement of the ball while gaze anticipated the ball's position (Mann, Spratford, & Abernethy, 2013).…”

When a Fly Ball Is Out of Reach: Catchability Judgments Are Not Based on Optical Acceleration Cancelation

“…That is to say, a fielder must be able to perceive whether his or her current locomotor efforts are sufficient for keeping constant d (tan α)/dt. When fielders track the ball with their gaze (see Oudejans et al, 1999; Postma et al, 2014), the elevation angle α equals the gaze angle. In this case, gaze angle can be the basis for using the Chapman strategy.…”

“…Not only locomotor behavior appears to be in line with the OAC strategy, also gaze behavior fits the use of optical acceleration. It has been shown that participants maintain continuous visual contact with the ball while running to make a catch, even for balls that fly overhead (Oudejans et al, 1999; Postma et al, 2014). Such gaze behavior fits naturally with the use of the OAC strategy, as it implies continuous visual control of interception.…”

A Tomada de Decisão (Bio)ética: Estudo Preliminar Utilizando o Mobile Eye Tracking

“…The investigation tried to determine if the initial moments would be essential or if it would be necessary to observe the ball either continuously or for a longer time to conclude if it was reachable or not. Despite the study being inconclusive, one envisages the possibility of achieving tangible results with better structured investigations and a higher number of participants being analysed 28 . Based on these preliminary investigations the present study may be considered a groundbreaking one, once one acknowledges that the use of the Mobile Eye Tracking for the investigation of matters concerning (bio)ethics is still incipient.…”