Experts Appear to Use Angle of Elevation Information in Basketball Shooting Rita Ferraz de Oliveira, Rao ˆul R. D. Oudejans, and Peter J. Beek VU University Amsterdam For successful basketball shooting, players must use information about the location of the basket relative to themselves. In this study, the authors examined to what extent shooting performance depends on the absolute distance to the basket (m) and the angle of elevation (). In Experiment 1, expert players took jump shots under different visual conditions (light, one dot glowing on the rim in the dark, and dark). Task performance was satisfactory under the one-dot condition, suggesting that m and  provided sufficient information during movement execution. In Experiment 2, expert wheelchair basketball players performed shots binocularly and monocularly, under one-dot and light conditions. Performance under the one-dot condition was similar binocularly and monocularly, suggesting that distance information was not crucial for the online control of shooting. In Experiment 3, experts took jump shots under light, one-dot, and dark conditions while the basket’s height was varied between trials unbeknownst to the participants. Players relied on  in combination with the official basket’s height to guide their shooting actions. In conclusion, basketball shooting appears to be based predominantly on angle of elevation information. Keywords: basketball shooting, optical information, angle of elevation, vision, expert Much research has been done to identify the optic information sources used in goal-directed movement. For example, the relative rate of optic expansion of an approaching object has been found to guide successful catching (e.g., Tresilian, 1993), and the zeroing out of optic acceleration has been identified as the perceptual basis of the interception of fly balls (Chapman, 1968; Dannemiller, Babler, & Babler, 1996; Michaels & Oudejans, 1992). Optic flow information has also been found to play a role in the control of both steering and walking (Wann & Swapp, 2000; Warren, Kay, Zosh, Duchon, & Sahuc, 2001). Within the context of these in- vestigations, it has become apparent that the optic variables that are relevant to the control of goal-directed action may be picked up through both retinal and extraretinal processes. For instance, in- formation from the neck muscles may help to detect optic accel- eration in catching fly balls (Oudejans, Michaels, Bakker, & Dav- ids, 1999), and the orientation and movements of the head and eye appear important in the control of heading (Loomis, 2001; Ooi, Wu, & He, 2001; Royden, Crowell, & Banks, 1994; Warren, 1998). Not only is identification of the sources of information that are exploited by humans performing goal-directed actions impor- tant from a theoretical point of view, it may also have implications for a broad range of practical applications, including virtual envi- ronments (e.g., Tarr & Warren, 2002) and robotics (e.g., Kurazume & Hirose, 2000; Rushton & Wann, 1999). Against this back- ground, it seems especially useful to examine optimal performance in tasks with high accuracy demands, such as sport actions per- formed by experienced athletes. The reason is that in the course of many years of practice, expert performers are likely to have become attuned to the variables that are most useful for the control of specific actions. In the present study, we examined what information sources are used by expert basketball players as they organize and deliver a basketball shot. Like most daily activities, basketball shooting occurs in a rich environment where multiple information sources are available that may be used to guide action. In addressing the topic of interest, we proceed by identifying the information sources that in principle could be sufficient for successful basketball shoot- ing. This initial step was constrained by findings of previous research indicating that players typically look at the basket just before and during shooting (de Oliveira, Oudejans, & Beek, 2006, 2008; Vickers, 1996), suggesting that sources of information es- sential for the localization of the target may be available to the player by directing their gaze at the basket. Moreover, although visual information gathered before the shot can contribute to spatial accuracy, basketball shooting strongly depends on optic information that is picked up during movement execution, partic- ularly toward ball release (de Oliveira, Huys, Oudejans, van de Langenberg, & Beek, 2007; de Oliveira et al., 2006). From this it follows that the information sources under scrutiny should be continuously available during movement execution. In three-dimensional space, the location of a target relative to an observer must be perceived in the back–forth direction (x-axis), right–left direction (y-axis), and up– down direction (z-axis). In basketball, the position of the basket is fixed in the z-axis, and it has been shown that players orient in the y-axis relatively early (de Rita Ferraz de Oliveira, Rao ˆul R. D. Oudejans, and Peter J. Beek, Research Institute MOVE, Faculty of Human Movement Sciences, VU University Amsterdam, Amsterdam, the Netherlands. We gratefully acknowledge Dinant Kistemaker and Rolf van de Langen- berg for their involvement in this study. We also thank Hans de Koning, Berry den Brinker, and Siro Otten for expert technical support and Ellen Vaessen and Tjitske Boonstra for their assistance in conducting the second experiment. Correspondence concerning this article should be addressed to Rita Ferraz de Oliveira, who is now at the Department of Psychology, Royal Holloway, University of London, Egham TW20 0EX, United Kingdom. E-mail: rita.oliveira@rhul.ac.uk CORRECTED NOVEMBER 18, 2009; SEE LAST PAGE Journal of Experimental Psychology: © 2009 American Psychological Association Human Perception and Performance 2009, Vol. 35, No. 3, 750 –761 0096-1523/09/$12.00 DOI: 10.1037/a0013709 750