Abstract
Unconstrained point-to-point human arm movements are generally gently curved, a fact which has been used to assess the validity of models of trajectory formation. In this study we examined the relationship between curvature perception and movement curvature for planar sagittal and transverse arm movements. We found a significant correlation (P<0.0001, n=16) between the curvature perceived as straight and the curvature of actual arm movements. We suggest that subjects try to make straight-line movements, but that actual movements are curved because visual perceptual distortion makes the movements appear to be straighter than they really are. We conclude that perceptual distortion of curvature contributes to the curvature seen in human point-to-point arm movements and that this must be taken into account in the assessment of models of trajectory formation.
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References
Abend W, Bizzi E, Morasso P (1982) Human arm trajectory formation. Brain 105:331–348
Atkeson CG, Hollerbach JM (1985) Kinematic features of unrestrained vertical arm movements. J Neurosci 5:2318–2330
Bernstein N (1967) The coordination and regulation of movements. Pergamon, London
Bryson AE, Ho YC (1975) Applied optimal control. Wiley, New York
Bullock D, Grossberg S (1988) Neural dynamics of planned arm movements: emergent invariants and speed accuracy properties during trajectory formation. Psychol Rev 95:49–90
Dobson AJ (1990) An introduction to generalized linear models. Chapman and Hall, London
Flash T (1987) The control of hand equilibrium trajectories in multi-joint arm movements. Biol Cybern 57:257–274
Flash T, Hogan N (1985) The co-ordination of arm movements: an experimentally confirmed mathematical model. J Neurosci 5:1688–1703
Foley JM (1980) Binocular distance perception. Psychol Rev 87:5:411–434
Hogan N (1984) An organizing principle for a class of voluntary movements. J Neurosci 4:2745–2754
Morasso P (1981) Spatial control of arm movements. Exp Brain Res 42:223–227
Uno Y, Kawato M, Suzuki R (1989) Formation and control of optimal trajectories in human multijoint arm movements: minimum torque change model. Biol Cybern 61:89–101
Wolpert DM, Ghahramani Z, Jordan MI 1993 On the role of extrinsic coordinates in arm trajectory planning: evidence from an adaptation study. MIT Computational Cognitive Science Technical Report 9308
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Wolpert, D.M., Ghahramani, Z. & Jordan, M.I. Perceptual distortion contributes to the curvature of human reaching movements. Exp Brain Res 98, 153–156 (1994). https://doi.org/10.1007/BF00229120
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DOI: https://doi.org/10.1007/BF00229120