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

Abstract

The optical acceleration cancelation (OAC) strategy, based on Chapman’s (1968) analysis of the outfielder problem, has been the dominant account for the control of running to intercept fly balls approaching head on. According to the OAC strategy, outfielders will arrive at the interception location just in time to catch the ball when they keep optical acceleration zero. However, the affordance aspect of this task, that is, whether or not an approaching fly ball is catchable, is not part of this account. The present contribution examines whether the scope of the OAC strategy can be extended to also include the affordance aspect of running to catch a fly ball. This is done by considering a fielder’s action boundaries (i.e., maximum running velocity and –acceleration) in the context of the OAC strategy. From this, only when running velocity is maximal and optical acceleration is non-zero, a fielder would use OAC to perceive a fly ball as uncatchable. The present contribution puts this hypothesis to the test. Participants were required to try to intercept fly balls projected along their sagittal plane. Some fly balls were catchable whereas others were not. Participants were required to catch as many fly balls as possible and to call ‘no’ when they perceived a fly ball to be uncatchable. Participants’ running velocity and –acceleration at the moment of calling ‘no’ were examined. Results showed that participants’ running velocity was submaximal before or while calling ‘no’. Also running acceleration was often submaximal. These results cannot be explained by the use of OAC in judging catchability and ultimately call for a new strategy of locomotor control in running to catch a fly ball.

Goalkeeping in the soccer penalty kick

“…It is crucially important to appreciate the subtle distinction with actions or movements being controlled by information, as ecological psychologists have traditionally argued (e. g., Lee, 1976;Michaels & Oudejans, 1992;Peper et al, 1994;Warren, 1988). Take forexample, anoutfielderinbaseball running to catch a fly ball (Postma, Smith, Pepping, van Andel, & Zaal, 2017; see also Fajen, 2007). According to a widely Abstract The goalkeeper's difficulty in the soccer penalty kick originates from the extreme spatiotemporal constraints of the situation.…”

“…The ball is only perceived as catchable for the fielder if she or he can run fast enough to cover the distance to the interception location in time. If the required running velocity exceeds the running speed that the outfielder can achieve (or maintain), then the fly ball is no longer perceived as catchable-in that case the outfielder is perhaps better off preparing to get the ball after a bounce (Postma et al, 2017). Consequently, to be successful, the outfielder must run in Review order to ensure that the required running velocity is kept within the limits of her or his running capabilities, that is, within the action boundaries.…”

Affordance-based versus current-future accounts of choosing whether to pursue or abandon the chase of a moving target

“…Fajen et al found that subjects' judgments were no more accurate when moving than when standing still. 1 More recent work investigating the interception of fly balls casts further doubt onto the current-future account (Postma, Lemmink, & Zaal, 2018;Postma, Otter, & Zaal, 2014;Postma, Smith, Pepping, van Andel, & Zaal, 2017). Postma et al (2017) found that at the moment that subjects reported fly balls as uncatchable, they were running at less than half of their maximum speed with negligible acceleration.…”

“…1 More recent work investigating the interception of fly balls casts further doubt onto the current-future account (Postma, Lemmink, & Zaal, 2018;Postma, Otter, & Zaal, 2014;Postma, Smith, Pepping, van Andel, & Zaal, 2017). Postma et al (2017) found that at the moment that subjects reported fly balls as uncatchable, they were running at less than half of their maximum speed with negligible acceleration. Such responses are inconsistent with any current-future account of perceiving catchability, including one based on the fly ball's optical acceleration, the dominant model for interception of a fly ball (Chapman, 1968;Fink, Foo, & Warren, 2009;Michaels & Oudejans, 1992), and are better explained from an affordance-based perspective (Postma et al, 2018).…”

“…Although evidence supporting the affordance-based account of catchability perception already exists (Fajen et al, 2011;Postma et al, 2014;Postma et al, 2017;Postma et al, 2018), the conclusions of those studies were based on perceptual judgments rather than on behavior during naturalistic interception tasks. The use of an action-based measure offers the opportunity to provide converging evidence and allay potential concerns about verbal judgments being noisy or contaminated measures of what actors actually perceive when they are engaged in a perceptual-motor task (Heft, 1993).…”