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Investigating Pain-Related Avoidance Behavior using a Robotic Arm-Reaching Paradigm
Published on: October 3, 2020
Missing in action: the effect of obstacle position and size on avoidance while reaching.
Craig S Chapman1, Melvyn A Goodale
1CIHR Group for Action and Perception, University of Western Ontario, London, ON, N6A 5C2, Canada.
Experimental Brain Research
|August 22, 2008
Summary
Humans possess a sophisticated obstacle avoidance system that adjusts reach trajectories to avoid collisions with objects. This system is sensitive to object size and position, ensuring safe navigation in cluttered environments.
Area of Science:
- Neuroscience
- Cognitive Psychology
- Biomechanics
Background:
- Obstacle avoidance during reaching is an automatic process, likely involving the dorsal stream.
- Previous studies suggest optic ataxia and visual form agnosia patients exhibit impaired obstacle avoidance.
Purpose of the Study:
- To quantify how normal participants adjust reaching movements in response to changes in non-target object size and position.
- To investigate the sensitivity and characteristics of the human obstacle avoidance system.
Main Methods:
- Experiment 1: 13 right-handed subjects reached to a target strip with non-target objects varying in depth and horizontal configuration.
- Experiment 2: Object height (tall/short) and depth were manipulated to assess their impact on reach trajectories.
Main Results:
- Asymmetric object placement caused reach deviations away from the objects, particularly when closer in depth.
- Reaches were slower when objects were closer in depth and proximity to the hand.
- Obstacle avoidance sensitivity extended to object size, with depth significantly modulating the effect.
Conclusions:
- Human obstacle avoidance is a highly sensitive and conservative system.
- The system dynamically evaluates potential obstacles based on proximity, size, and configuration.
- This sophisticated system ensures efficient and safe navigation in complex environments.
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