These studies examined motion trajectories and electromyographic (EMG) activity patterns during human horizontal reaching movements towards single- and double-step visual targets. These data were used to test and elaborate a model of two-joint planar arm movement based on the equilibrium point (EP) hypothesis or $ lambda$ model of motor control. This work aims to understand how reaching movements are planned and controlled by the nervous system. To this end, simulated trajectories and EMG patterns, generated with hypothetical central commands, were compared to empirical trajectories and EMG patterns. In general, the model was able to predict trajectories but was less successful in predicting EMG patterns. The results indicated that, in general, motions to both single- and double-step targets are generated by shifting the EP of the hand in a straight line towards the present target. Thus, a common control strategy underlying movements to single-step targets and trajectory modifications to double-step targets is proposed. Whereas the direction of shift of the EP is specified at the level of the hand, the rate of shift may be limited at the joint level.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.70293 |
| Date | January 1991 |
| Creators | Flanagan, John Randall |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Doctor of Philosophy (Department of Psychology.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001275407, proquestno: AAINN74655, Theses scanned by UMI/ProQuest. |
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