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Published on: October 10, 2020
Proprioceptive bimanual test in intrinsic and extrinsic coordinates
Riccardo Iandolo1, Valentina Squeri2, Dalia De Santis2
1NeuroLab, Department of Informatics, Bioengineering, Robotics and Systems Engineering, University of Genoa , Genoa , Italy ; Motor Learning and Robotic Rehabilitation Laboratory, Department of Robotics, Brain and Cognitive Sciences, Istituto Italiano di Tecnologia , Genoa , Italy.
This study explored hand-matching accuracy between extrinsic and intrinsic spatial representations. Results indicate extrinsic spatial matching is more accurate, suggesting cognitive task representation influences performance.
Area of Science:
- Neuroscience
- Human Motor Control
- Cognitive Psychology
Background:
- The brain utilizes both extrinsic (spatial) and intrinsic (joint angle) coordinates for motor control.
- Understanding how these representations interact is crucial for deciphering body schema organization.
Purpose of the Study:
- To investigate differences in hand-position matching accuracy between extrinsic and intrinsic spatial tasks.
- To determine which spatial representation (extrinsic or intrinsic) is more effective for accurate hand-matching.
Main Methods:
- Healthy subjects matched passive movements of their non-dominant hand's fingertip to target locations with their dominant hand.
- Two matching conditions were tested: same spatial location (extrinsic) and mirror-symmetric locations (intrinsic).
Main Results:
- Most subjects demonstrated higher matching accuracy in the extrinsic modality, with lower systematic error and variability.
- This accuracy advantage persisted even when arm configurations were identical across both modalities.
Conclusions:
- Hand-matching performance is influenced by both proprioceptive input and the cognitive representation of the task.
- Representing the goal in extrinsic space (physical location) appears more effective than intrinsic space (joint angles) for accurate matching.
