WRIGHT 9601140 Aimed movements are a ubiquitous part of everyday life. Of particular importance is their central role in situations involving the transfer of information between people and machines (e.g., mouse movements by computer users, control stick movements by pilots and heavy machine operators, etc.). A fundamental constraint on the control of aimed movements is described by speed-accuracy tradeoffs (SATs), i.e., faster movements are less accurate. Using the stochastic optimized-submovement model (SOSM) proposed by David Meyer and his associates as a starting point, this research will investigate the control of aimed movements in four areas: (a) the generality of SATs for multi-joint movements, (b) transfer of practice effects across the SATs, (c) the existence of corrective submovements during aimed movement, and (d) what is learned as SATs improve. The SOSM provides only one of several theoretical frameworks within which the results of this research can be interpreted. The research is, therefore, intended to (a) probe the empirical limits of these existing theories, (b) resolve fundamental disputes among these theories concerning the nature of the control of aimed movements, and (c) gather the database required either to elaborate one of the existing models or to propose a new theoretical framework, depending upon the nature of the results. Through a better understanding of aimed movements, this research should provide insights into how to structure control tasks. In addition, because the research includes both studies of how individuals differ in the nature and their use of submovements and studies of how performance improves when individuals practice aimed movements, it will shed light on issues such as personnel selection and how to organize training for jobs involving person- machine interaction through aimed movements. ***
