Continuous visual control of interception

Research Institute MOVE, Faculty of Human Movement Sciences, VU University Amsterdam, Van der Boechorststraat 9, NL-1081 BT Amsterdam, The Netherlands.
Human movement science (Impact Factor: 1.6). 02/2011; 30(3):475-94. DOI: 10.1016/j.humov.2010.12.007
Source: PubMed


People generally try to keep their eyes on a moving target that they intend to catch or hit. In the present study we first examined how important it is to do so. We did this by designing two interception tasks that promote different eye movements. In both tasks it was important to be accurate relative to both the moving target and the static environment. We found that performance was more variable in relation to the structure that was not fixated. This suggests that the resolution of visual information that is gathered during the movement is important for continuously improving predictions about critical aspects of the task, such as anticipating where the target will be at some time in the future. If so, variability in performance should increase if the target briefly disappears from view just before being hit, even if the target moves completely predictably. We demonstrate that it does, indicating that new visual information is used to improve precision throughout the movement.

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Available from: Jeroen Smeets
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    • "When interacting with moving objects, they ignore the moving objects' accelerations for controlling various aspects of their movements (Benguigui & Bennett, 2010;Lee, Young, Reddish, Lough, & Clayton, 1983;Port, Lee, Dassonville, & Georgopoulos, 1997). In many of the cases in which acceleration is not evidently ignored, the apparent use of information about the object's acceleration might just reflect the fact that movements are continuously adjusted on the basis of continuously updated estimates of the object's position (Brenner & Smeets, 2011;Dubrowski & Carnahan, 2002) and velocity (Brenner, de Lussanet, & Smeets, 2002). When the acceleration of horizontally moving targets that people are trying to intercept is varied randomly across trials, people make systematic errors that correspond with ignoring the acceleration during the delay between when visual information reaches the eye and when the arm responds to such information (Brenner & Smeets, 2015). "
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    ABSTRACT: People are known to be very poor at visually judging acceleration. Yet, they are extremely proficient at intercepting balls that fall under gravitational acceleration. How is this possible? We previously found that people make systematic errors when trying to tap on targets that move with different constant accelerations or decelerations on interleaved trials. Here, we show that providing contextual information that indicates how the target will decelerate on the next trial does not reduce such errors. Such errors do rapidly diminish if the same deceleration is present on successive trials. After observing several targets move with a particular acceleration or deceleration without attempting to tap on them, participants tapped as if they had never experienced the acceleration or deceleration. Thus, people presumably deal with acceleration when catching or hitting a ball by compensating for the errors that they made on preceding attempts.
    Preview · Article · Jan 2016 · i-Perception
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    • "The target moved for considerably longer than 116 ms, but assuming that the tapping movement is continuously adjusted (Brenner & Smeets, 2011), we would only expect to see effects of anything that is ignored during the final part of the movement, when sensorimotor delays prevent direct feedback-based correction. A sensorimotor delay of about 116 ms is reasonably consistent with the literature (Brenner & Smeets, 1997; Carlton, 1981; Oostwoud Wijdenes et al., 2011). "
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    ABSTRACT: People can hit rapidly moving balls with amazing precision. To determine how they manage to do so, we explored how various factors that we could manipulate influenced people's precision when intercepting virtual targets. We found that temporal precision was highest for fast targets that subjects were free to intercept wherever they wished. Temporal precision was much poorer when the point of interception was specified in advance. Examining responses to abrupt perturbations of the target's motion revealed that people adjusted where rather than when they would hit the target if given the choice. A model that combines judging how long it will take to reach the target's path with estimating the target's position at that time from its visually perceived position and velocity could account for the observed precision with reasonable values for all the parameters. The model considers all relevant sources of errors, together with the delays with which the various aspects can be adjusted. Our analysis provides a biologically plausible explanation for how light falling on the eye can guide the hand to intercept a moving ball with such high precision. © 2015 ARVO.
    Full-text · Article · Mar 2015 · Journal of Vision
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    • "Experimental evidence of visual control in the course of action has shown for arm and hand movements (e.g. grasping a static target (Goodale, 2011); intercepting a moving target (Brenner & Smeets, 2011)), as well as driving (Wallis et al., 2007). "
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    ABSTRACT: An experiment was conducted in a driving simulator to test how eye-movement patterns evolve over time according to the decision-making processes involved in a driving task. Participants had to drive up to a crossroads and decide to stop or not. The decision-making task was considered as the succession of two phases associated with cognitive processes: Differentiation (leading to a prior decision) and Consolidation (leading to a final decision). Road signs (Stop, Priority and GiveWay) varied across situations, and the stopping behavior (Go and NoGo) was recorded. Saccade amplitudes and fixation durations were analyzed. Specific patterns were found for each condition in accordance with the associated processes: high visual exploration (larger saccade amplitudes and shorter fixation durations) for the Differentiation phase, and lower visual exploration (smaller saccades and longer fixations) for the Consolidation phase. These results support that eye-movements can provide good indexes of underlying processes occurring during a decision-making task in an everyday context.
    Full-text · Article · Aug 2014 · Journal of Eye Movement Research
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