The influence of athletic experience and kinematic information on skill-relevant affordance perception

Abstract

Humans can perceive affordances both for themselves and for others, and affordance perception is a function of perceptual–motor experience involved in playing a sport. Two experiments investigated the enhanced affordance perception of athletes. In Experiment 1, basketball players and nonbasketball players provided perceptual reports for sports-relevant (maximum standing-reach and reach-with-jump heights) and non-sports-relevant (maximum sitting height) affordances for self and other. Basketball players were more accurate at perceiving maximum reach-with-jump for another person than were nonbasketball players, but were no better at perceiving maximum reach or sitting heights. Experiment 2 investigated the informational basis for this enhanced perceptual ability of basketball players by evaluating whether kinematics inform perceivers about action-scaled (e.g., force-production dependent), but not body-scaled (i.e., geometrically determined), affordances for others, and whether basketball experience enhances sensitivity to kinematic information. Only basketball players improved at perceiving an action-scaled affordance (maximum reach-with-jump), but not body-scaled affordances (maximum standing-reach and sit) with exposure to kinematic information, suggesting that action-scaled affordances may be specified by kinematic information to which athletes are already attuned by virtue of their sport experience.

Keywords:

• Affordance perception
• Information
• Expertise
• Athletes
• Perceptual learning
• Visual perception

Acknowledgments

This research was supported by NSF grants BCS-0716319, HSD-0728743, and BCS-0926662. This research was completed by Julie A. Weast in partial fulfilment of the requirements for the Master of Arts degree in psychology at the University of Cincinnati. We would like to thank Kenneth Wright and Michael Tolston for their assistance with data collection and Sarah Cummins-Sebree for her helpful comments on this manuscript.

Notes

¹ In Experiment 1, no differences were found between the groups in their (self) maximum standing-reach and sitting heights (ps > .05); however, there was a significant difference in their maximum reach-with-jump heights, t(20) = 3.46, p = .003, such that basketball players could reach higher while jumping than could nonplayers. There were no differences between the model and basketball players in their (self) maximum standing-reach, reach-with-jump, and sitting heights (ps > .05). There were significant differences found between the model and nonplayers in their (self) maximum standing-reach heights, t(10) = –2.41, p = .04, reach-with-jump heights, t(10) = –3.97, p = .003, and sitting heights, t(10) = –4.74, p = .0008, such that the model could reach higher while standing and while jumping than could nonbasketball players and also had a significantly higher maximum sitting height than nonplayers.

² Given that previous studies have shown influences of eye-height and the perceivers' own action capabilities on the perception of affordances for self and others (Ramenzoni et al., 2008b; Wraga, 1999), we examined these influences on the participants' affordance reports in the current study. The eye-heights of both basketball players and nonplayers were correlated with their self maximum standing-reach reports (r²  = .58, p = .007, and r²  = .72, p = .0009, respectively). The eye-heights of neither basketball players nor nonplayers were correlated with their maximum standing-reach reports for the model (ps > .05). Consistent with Ramenzoni et al. (2008b), the actual maximum standing-reach heights of nonplayers were correlated with their standing-reach reports for the model (r²  = .49, p = .017) although the actual maximum standing-reach heights of basketball players were not (p > .05).

³ The eye-heights of nonplayers were correlated with their self maximum reach-with-jump reports (r²  = .54, p = .01); however, the eye-heights of basketball players were not (p > .05). The eye-heights of neither basketball players nor nonplayers were correlated with their maximum reach-with-jump reports for the model (ps > .05). The actual maximum reach-with-jump heights of nonplayers were correlated with their standing-reach reports for the model (r²  = .38, p = .045); the actual maximum reach-with-jump heights of basketball players were not (p > .05).

⁴ The eye-heights of basketball players were correlated with their own maximum sit reports (r²  = .37, p = .046); however, unlike previous research (Mark, 1987) the eye-heights of nonplayers were not (p > .05). The eye-heights of neither basketball players nor nonplayers were correlated with their maximum sit reports for the model (ps > .05). The actual maximum sit heights of neither basketball players nor nonplayers were correlated with their reports for the model (all ps > .05).

⁵ Stoffregen et al. (1999) demonstrated that observers were able to differentiate the maximum sitting height of a short and tall actor after watching a point-light display video of the actors performing actions (marching in place, squatting, walking) while standing next to a chair (upon which they were to sit). This suggests that kinematic information available in the actions of the actors influenced the observer's predictions about their maximum sitting height (a body-scaled affordance). However, when the chair was removed from the video (in which the actors performed the same actions) and was placed next to the monitor on which the videos were shown to the observers (such that the physical chair was always in view but was not featured in the point-light displays), observers were unable to differentiate the sitting capabilities of the short and tall actors. This suggests that participants were not using kinematic information about forces (e.g., force production capabilities) to perceive the body-scaled affordance of sitting. What is more likely is that participants relied on information capturing geometric relations within the common reference frame of the actor and the chair available in the point-light displays when the chair was present in the video relative to the actor, given that sitting is a body-scaled affordance.

⁶ In Experiment 2, no differences were found between the groups in their (self) maximum standing-reach and sitting heights (ps > .05); however, there was a significant difference in their maximum reach-with-jump heights, t(44) = 2.62, p = .012, such that basketball players could reach higher while jumping than nonbasketball players. There were significant differences found between the model and basketball players in their (self) maximum standing-reach heights, t(22) = –3.01, p = .007, and sitting heights, t(22) = –2.24, p = .04, such that the model could reach higher while standing and had a higher maximum sitting height than basketball players. There was no difference found between the model and basketball players in their maximum reach-with-jump heights (p > .05). There were significant differences found between the model and nonbasketball players in their (self) maximum standing-reach heights, t(22) = –5.13, p < .0001, reach-with-jump heights, t(22) = –6.76, p < .0001, and sitting heights, t(23) = –4.56, p = .0001, such that the model could reach higher while standing and while jumping than could nonbasketball players and also had a significantly higher maximum sitting height than nonbasketball players.

⁷ In Phase 1, the eye-heights of neither basketball players nor nonplayers were correlated with the maximum standing-reach reports for the model for both information conditions (ps > .05). In Phase 2, the eye-heights of nonplayers were not correlated with maximum standing-reach reports for the model in both information conditions (ps > .05). The eye-heights of basketball players were not correlated with their maximum standing-reach reports for the model in the no-kinematics condition (p > .05); however, the eye-heights of basketball players in the kinematics condition were correlated with their standing-reach reports for the model (r²  = .38, p = .032). In both phases and in both information conditions, the actual maximum standing-reach heights of neither basketball players nor nonplayers were correlated with their reports for the model (all p > .05).

⁸ In Phases 1 and 2, the eye-heights of neither basketball players nor nonplayers in both information conditions were correlated with maximum reach-with-jump reports for the model (ps > .05). In both phases and in both information conditions, the actual maximum reach-with-jump heights of neither basketball players nor nonplayers were correlated with their reports for the model (all p > .05).

⁹ In Phases 1 and 2, the eye-heights of neither basketball players nor nonplayers in both information conditions were correlated with maximum sit reports for the model (ps > .05). In both phases and in both information conditions, the actual sit heights of neither basketball players nor nonplayers were correlated with their reports for the model (all p > .05).