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.
Citation countsare sourced monthly fromand citation databases.
These databases contain citations from different subsets of available publications and different time periods and thus the citation count from each is usually different. Some works are not in either database and no count is displayed. Scopus includes citations from articles published in 1996 onwards, and Web of Science generally from 1980 onwards.
Citations counts from theindexing service can be viewed at the linked Google Scholar™ search.
Full-text downloadsdisplays the total number of times this work’s files (e.g., a PDF) have been downloaded from QUT ePrints as well as the number of downloads in the previous 365 days. The count includes downloads for all files if a work has more than one.
Repository Staff Only: item control page