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document
Locomoting-to-reach : information variables and control strategies for nested actions . Locomoting-to-reach is a basic perception/action behavior that requires visual information for the control of both locomotion and reaching components . We investigated the visual information and the control strategies used to guide both the head and the hand on approach to a target in a locomotion-to-reach task . In this study , participants were required to locomote in the dark to a lit target in three different conditions : monocular vision/target with image size , binocular vision/target with image size , and binocular vision/point-light target ( without image size ) . In task one , participants brought their eyes to the target . In task two , participants brought their outstretched hand to the target . Movement trajectories for both tasks were analyzed . Results show that participants were significantly more accurate when binocular information was present . In both tasks , participants were found to use a proportional rate control strategy rather than a constant τ strategy . In the walk-to-reach task , they used monocular and/or binocular τ information to guide the head and then switched to using relative disparity τ to guide the hand to final target acquisition , switching when the hand centric τ became less than the head centric τ. Dynamical models of the information and control strategies were used to perform simulations that were found to fit the data well . The conclusion is that proportional rate control is used sequentially with head centric , then hand-centric τ-based information , using at each moment the τ with the smallest value .
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Intervention_Physical
Locomoting-to-reach
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Intervention_Physical
Locomoting-to-reach
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Intervention_Physical
locomotion-to-reach task
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Outcome_Physical
Movement trajectories
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Outcome_Other
accurate when binocular information was present
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Participant_Condition
participants were required to locomote in the dark to a lit target in three different conditions : monocular vision/target with image size , binocular vision/target with image size , and binocular vision/point-light target ( without image size ) .