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Updated: Jul 5, 2026
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Creating Objects and Object Categories for Studying Perception and Perceptual Learning
Published on: November 2, 2012
Flexible representations of dynamics are used in object manipulation
Alaa A Ahmed1, Daniel M Wolpert1, J Randall Flanagan2
1Computational and Biological Learning Lab, Department of Engineering, University of Cambridge, Cambridge CB2 1PZ, United Kingdom.
Current Biology : CB
|May 20, 2008
Summary
The brain flexibly represents object dynamics using different coordinate frames. Familiar object dynamics are encoded in object-centered coordinates, while unfamiliar ones use arm-centered coordinates.
Area of Science:
- Neuroscience
- Motor Control
- Human Sensorimotor System
Background:
- Skillful object manipulation requires the brain to learn object dynamics, the relationship between force and motion.
- A key question in sensorimotor control is whether these dynamics are represented intrinsically (arm-centered) or extrinsically (object-centered).
- Prior studies suggested arm-centered representations, but used objects with complex, unnatural dynamics.
Purpose of the Study:
- To investigate how the brain represents the dynamics of objects with natural dynamics.
- To determine if object dynamics representation differs based on object familiarity and sensory input.
Main Methods:
- Participants manipulated objects with simple (familiar) and complex (unfamiliar) dynamics.
- Object dynamics representation was assessed in conditions with and without visual feedback.
- Behavioral data were analyzed to infer the coordinate frames used for motor control.
Main Results:
- Objects with simple dynamics were represented in object-centered coordinates.
- Objects with complex dynamics were represented in arm-centered coordinates.
- When visual feedback was removed, simple dynamics were represented in an intermediate coordinate frame.
Conclusions:
- The brain flexibly employs different coordinate frames for representing object dynamics based on familiarity and sensory context.
- With experience, the neural representation of object dynamics may shift from arm-centered to object-centered frames.
- Object-centered representations are advantageous for familiar objects, enabling manipulation irrespective of hand orientation.
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