Optimizing risk in action: Differences between fixated aim points and movement outcomes in throwing

Introduction Movement outcomes are inherently subject to variance. Handling this variance is crucial for successful sensorimotor behaviour – whether in everyday life or in sports –, particularly in high-risk situations. Research using finger-pointing tasks has shown that humans take into account th...

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Main Authors: Stephan Zahno, Damian Beck, Ralf Kredel, André Klostermann, Ernst-Joachim Hossner
Format: Article
Language:English
Published: Bern Open Publishing 2025-01-01
Series:Current Issues in Sport Science
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Online Access:https://ciss-journal.org/article/view/12052
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author Stephan Zahno
Damian Beck
Ralf Kredel
André Klostermann
Ernst-Joachim Hossner
author_facet Stephan Zahno
Damian Beck
Ralf Kredel
André Klostermann
Ernst-Joachim Hossner
author_sort Stephan Zahno
collection DOAJ
description Introduction Movement outcomes are inherently subject to variance. Handling this variance is crucial for successful sensorimotor behaviour – whether in everyday life or in sports –, particularly in high-risk situations. Research using finger-pointing tasks has shown that humans take into account their own motor variance and costs of potential outcomes in movement planning (Trommershäuser et al., 2008). However, the question remains whether this mechanism extends to more complex tasks (Beck et al., 2023). Here, we investigate sensorimotor behaviour under risk in throwing, across three experiments with 20 participants each. Methods Participants’ task was to throw balls on a target circle in a virtual reality (VR) setup, gaining 100 points for each hit. The target was partially overlapped by a penalty circle. We manipulated the consequences of hitting the penalty circle (0 points vs -500 points vs -2000 points) and the distance between both circles (30 cm vs 45 cm vs 60 cm). This task challenged participants to find strategies that optimally trade-off potential penalties and rewards. To capture participants’ strategies, we measured the location of their final gaze fixation before movement – as an indicator of their planned aiming point – and the ball’s impact location. Models of statistical decision theory (Trommershäuser et al., 2008) predict that the optimal aim point horizontally shifts away from the centre of the target circle as soon as the penalty is non-zero. In other words, participants should incorporate a “safety margin”. This horizontal shift should be larger with (1) higher penalties, (2) smaller distances between the target and penalty circle and (3) with higher motor variance. Results In the no-penalty condition, the final fixation and the ball’s impact location were both centred on the target. In the penalty condition, both their final fixations and the ball’s impact location shifted away from the penalty circle, with larger shifts for higher penalties and smaller distances. Intriguingly, the shifts in the ball’s actual impact location were not only significantly larger (“more conservative”) but also closer to the statistically optimal location compared to the initially fixated aim points. Analysis of movement trajectories shows that, in penalty conditions, the shifts away from the penalty zone increased progressively until the final phases of the movement. Conclusion Our findings show that principles of statistical decision theory generalize to more complex tasks. Extending Trommershäuser et al. (2008)., our results suggest that risk evaluation is not completed in a planning phase before movement execution but is optimized during ongoing movements. References Beck, D., Hossner, E.-J., & Zahno, S. (2023). Mechanisms for handling uncertainty in sensorimotor control in sports: A scoping review. International Review of Sport and Exercise Psychology, 1–35. https://doi.org/10.1080/1750984X.2023.2280899 Trommershäuser, J., Maloney, L. T., & Landy, M. S. (2008). Decision making, movement planning and statistical decision theory. Trends in Cognitive Sciences, 12(8), 291–297. https://doi.org/10.1016/j.tics.2008.04.010
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spelling doaj-art-3fe40f70fefa4b34801c12fe9d3a4fcb2025-02-04T03:15:05ZengBern Open PublishingCurrent Issues in Sport Science2414-66412025-01-0110210.36950/2025.2ciss071Optimizing risk in action: Differences between fixated aim points and movement outcomes in throwingStephan Zahno0Damian Beck1Ralf Kredel2André Klostermann3Ernst-Joachim Hossner4University of Bern, SwitzerlandUniversity of Bern, SwitzerlandUniversity of Bern, SwitzerlandUniversity of Bern, SwitzerlandUniversity of Bern, Switzerland Introduction Movement outcomes are inherently subject to variance. Handling this variance is crucial for successful sensorimotor behaviour – whether in everyday life or in sports –, particularly in high-risk situations. Research using finger-pointing tasks has shown that humans take into account their own motor variance and costs of potential outcomes in movement planning (Trommershäuser et al., 2008). However, the question remains whether this mechanism extends to more complex tasks (Beck et al., 2023). Here, we investigate sensorimotor behaviour under risk in throwing, across three experiments with 20 participants each. Methods Participants’ task was to throw balls on a target circle in a virtual reality (VR) setup, gaining 100 points for each hit. The target was partially overlapped by a penalty circle. We manipulated the consequences of hitting the penalty circle (0 points vs -500 points vs -2000 points) and the distance between both circles (30 cm vs 45 cm vs 60 cm). This task challenged participants to find strategies that optimally trade-off potential penalties and rewards. To capture participants’ strategies, we measured the location of their final gaze fixation before movement – as an indicator of their planned aiming point – and the ball’s impact location. Models of statistical decision theory (Trommershäuser et al., 2008) predict that the optimal aim point horizontally shifts away from the centre of the target circle as soon as the penalty is non-zero. In other words, participants should incorporate a “safety margin”. This horizontal shift should be larger with (1) higher penalties, (2) smaller distances between the target and penalty circle and (3) with higher motor variance. Results In the no-penalty condition, the final fixation and the ball’s impact location were both centred on the target. In the penalty condition, both their final fixations and the ball’s impact location shifted away from the penalty circle, with larger shifts for higher penalties and smaller distances. Intriguingly, the shifts in the ball’s actual impact location were not only significantly larger (“more conservative”) but also closer to the statistically optimal location compared to the initially fixated aim points. Analysis of movement trajectories shows that, in penalty conditions, the shifts away from the penalty zone increased progressively until the final phases of the movement. Conclusion Our findings show that principles of statistical decision theory generalize to more complex tasks. Extending Trommershäuser et al. (2008)., our results suggest that risk evaluation is not completed in a planning phase before movement execution but is optimized during ongoing movements. References Beck, D., Hossner, E.-J., & Zahno, S. (2023). Mechanisms for handling uncertainty in sensorimotor control in sports: A scoping review. International Review of Sport and Exercise Psychology, 1–35. https://doi.org/10.1080/1750984X.2023.2280899 Trommershäuser, J., Maloney, L. T., & Landy, M. S. (2008). Decision making, movement planning and statistical decision theory. Trends in Cognitive Sciences, 12(8), 291–297. https://doi.org/10.1016/j.tics.2008.04.010 https://ciss-journal.org/article/view/12052Motor ControlSensorimotor UncertaintyStatistical Decision Theory
spellingShingle Stephan Zahno
Damian Beck
Ralf Kredel
André Klostermann
Ernst-Joachim Hossner
Optimizing risk in action: Differences between fixated aim points and movement outcomes in throwing
Current Issues in Sport Science
Motor Control
Sensorimotor Uncertainty
Statistical Decision Theory
title Optimizing risk in action: Differences between fixated aim points and movement outcomes in throwing
title_full Optimizing risk in action: Differences between fixated aim points and movement outcomes in throwing
title_fullStr Optimizing risk in action: Differences between fixated aim points and movement outcomes in throwing
title_full_unstemmed Optimizing risk in action: Differences between fixated aim points and movement outcomes in throwing
title_short Optimizing risk in action: Differences between fixated aim points and movement outcomes in throwing
title_sort optimizing risk in action differences between fixated aim points and movement outcomes in throwing
topic Motor Control
Sensorimotor Uncertainty
Statistical Decision Theory
url https://ciss-journal.org/article/view/12052
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AT andreklostermann optimizingriskinactiondifferencesbetweenfixatedaimpointsandmovementoutcomesinthrowing
AT ernstjoachimhossner optimizingriskinactiondifferencesbetweenfixatedaimpointsandmovementoutcomesinthrowing