Variability Effects on the Internal Structure of Rapid Aiming Movements

Worringham, Charles J. (1991) Variability Effects on the Internal Structure of Rapid Aiming Movements. Journal of Motor Behavior, 23(1), pp. 75-85.



Two experiments are reported in which the effects of different levels of spatial variability in the initial phase of aiming movements were explored. It was found that longer, faster, and more spatially variable initial submovements were associated with an almost proportional increase in the distance between the average location at which the first submovement ended and the target. the first experiment involved a multisegmental arm motion that required a direction reversal, in which spatial variability could be estimated in all three dimensions. The second was a unidirectional, one-degree-of-freedom wrist supination task. The variability-amplitude relationship for the initial submovement was present in both. It is argued that the variability, or unpredictability, of the initial submovement is a determinant of its average amplitude, such that initial submovements approach the target as closely as is permitted by the level of variability. Such a mechanism allows task constraints such as accuracy requirements and allowable error rates to be met most efficiently, in a manner similar to the recently described optimisation of submovement durations. If this mechanism is a general, ubiquitous phenomenon in rapid aiming, certain features of its internal kinematic structure are predictable. A set of five such predictions is outlined.

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31 citations in Web of Science®
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ID Code: 1959
Item Type: Journal Article
Refereed: Yes
Additional URLs:
Keywords: variability, aiming, kinematics, predictions, undershoot, clearance
ISSN: 0022-2895
Subjects: Australian and New Zealand Standard Research Classification > PSYCHOLOGY AND COGNITIVE SCIENCES (170000) > PSYCHOLOGY (170100) > Sensory Processes Perception and Performance (170112)
Australian and New Zealand Standard Research Classification > MEDICAL AND HEALTH SCIENCES (110000) > NEUROSCIENCES (110900) > Neurosciences not elsewhere classified (110999)
Australian and New Zealand Standard Research Classification > MEDICAL AND HEALTH SCIENCES (110000) > HUMAN MOVEMENT AND SPORTS SCIENCE (110600) > Motor Control (110603)
Divisions: Current > QUT Faculties and Divisions > Faculty of Health
Current > Institutes > Institute of Health and Biomedical Innovation
Copyright Owner: Copyright 1991 Heldref Publications
Copyright Statement: Reproduced in accordance with the copyright policy of the publisher.
Deposited On: 16 Aug 2005 00:00
Last Modified: 01 Sep 2010 12:38

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