Showing papers by "Marc Jeannerod published in 1990"

The coupling of arm and finger movements during prehension.

Abstract: The experiments reported here were aimed at testing the degree of coupling of motor components during the act of prehension. Hand movements were recorded bidimensionnally by a Selspot system which monitored the displacement of IREDS placed at the thumb and index finger tips, at the metacarpophalangeal joint of the index and at the radial styloid. Targets were three-dimensional translucent dowels placed concentrically at 30 cm from the subject. The dowels were 10 degrees apart from each other. In blocked and control trials, one dowel was illuminated and served as a target for the movement. In the perturbed trials (20% of cases) one dowel was illuminated first and the light was unexpectedly shifted to another dowel at the onset of the subject's movements. Kinematic analysis of the movement revealed the following: 1. In blocked and control trials, the wrist moved with a single acceleration to the target dowel. Meanwhile, the finger grip (computed as the distance between thumb and index IREDS) increased up to a maximum size, located in time at about 60% of movement time and then decreased until contact with the dowel. 2. In perturbed trials the initial wrist acceleration was aborted. A new acceleration started about 180 ms after the first, in order to reorient the hand to the new target. Similarly, the initial grip aperture also aborted and reincreased in synchrony with the second wrist acceleration. 3. Perturbations increased movement time by only 95 ms on average. The first peak in acceleration indicating abortion of the initial movement occurred 100 ms after the movement onset, i.e., 30 ms earlier than in non perturbed trials.(ABSTRACT TRUNCATED AT 250 WORDS)

Motor representation and control

Abstract: Contents: Section 1:Association Lecture. S. Sternberg, R.L. Knoll, D.L. Turock, On Hierarchical Control in the Execution of Action Sequences. Section 2:Tutorials on the Basic Organization Principles of Motor Representations. M. Wiesendanger, The Motor Cortical Areas and the Problem of Hierarchies. S.W. Keele, A. Cohen, R. Ivry, Motor Programs: Concepts and Issues. M.A. Arbib, Programs, Schemas and Neural Networks for Control of Hand Movements: Beyond the RS Framework. J.A.S. Kelso, J.D. DelColle, G. Sch ner, Action-Perception as a Pattern Formation Process. Section 3:Movement Initiation and Motor Output Specification in Voluntary Action. D.E. Meyer, J.E. Keith Smith, S. Kornblum, R.A. Abrams, C.E. Wright, Tutorial: Speed-Accuracy Tradeoffs in Aimed Movements: Toward a Theory of Rapid Voluntary Action. A.P. Georgopoulos, Neurophysiology of Reaching. C. Ghez, W. Hening, M. Favilla, Response Initiation and Specification of Response Features: Parallel Interacting Channels. C.E. Wright, Generalized Motor Programs: Reevaluating Claims of Effector Independence. D.A. Rosenbaum, F. Marchak, H.J. Barnes, J. Vaughan, J.D. Slotta, M.J. Jorgensen, Constraints for Action Selection: Overhand Versus Underhand Grips. Section 4:The Structure of Motor Patterns in Learned Movements and Speech. P. Viviani, Tutorial: Common Factors in the Control of Free and Spontaneous Movements. C.L. MacKenzie, D.L. Van Eerd, Rhythmic Precision in the Performance of Piano Scales: Motor Psychophysics and Motor Programming. A. Semjen, R. Gottsdanker, Rapid Serial Movements. Relation Between the Planning of Sequential Structure and Effector Selection. B. Tuller, J.A.S. Kelso, Phase Transitions in Speech Production: Empirical Observations. P.F. MacNeilage, B. Davis, Acquisition of Speech Production. Frames, Then Content. Section 5:Sensorimotor Transformation and the Representation of Action Coordinates. J.F. Soechting, C.A. Terzuolo, Tutorial: Sensorimotor Transformations and the Kinematics of Arm Movements in Three- Dimensional Space. J. Droulez, C. Darlot, The Geometric and Dynamic Implications of the Coherence Constraints in the Three-Dimensional Sensorimotor Interaction. J.R. Lackner, Sensory-Motor Adaptation to High Force Levels in Parabolic Flight Maneuvers. J.P. Roll, J.C. Gilhodes, R. Roll, J.L. Velay, Contribution of Skeletal and Extraocular Proprioception to Kinaesthetic Representation. H. Honda, Eye Movements to a Visual Stimulus Flashed Before, During, or After a Saccade. D.N. Lee, B.M. Daniel, J. Turnbull, Basic Perceptuo-Motor Dysfunctions in Cerebral Palsy. G. Butterworth, L. Grover, Joint Visual Attention, Manual Pointing and Pre-Verbal Communication in Human Infancy. Section 6:The Role of Sensory-Based Adjustments in the Achievement of the Goal. J.H. Abbs, C.J. Winstein, Tutorial: Functional Contributions of Rapid and Automatic Sensory-Based Adjustments to Motor Output. C. Prablanc, D. Pelisson, Gaze Saccade Orienting and Hand Pointing are Locked to Their Goal by Quick Internal Loops. R. Johansson, G. Westling, Tactile Afferent Signals in the Control of Precision Grip. J.N. Sanes, Motor Representations in Deafferented Humans: A Mechanism for Disordered Movement Performance. Section 7:Constraints on Motor Learning and Development. C. von Hofsten, Tutorial: A Perception-Action Perspective on the Development of Manual Movements. D.E. Young, R.A. Schmidt, C.A. Lange, Units of Motor Behavior: Modifications with Practice and Feedback. M.I. Jordan, Learning and the Degrees of Freedom Problem. P. Faglioni, A. Basso, C. Botti, S. Aglioti, C. Saetti, Gesture Learning and Apraxia.