The aim of this project is to develop a detailed model of the planning and control of voluntary movements in humans. Fundamental knowledge in this area can inform robotics, physical education and rehabilitation, and the design of human-machine systems. Three lines of experiments will be pursued. One will focus on a phenomenon recently discovered in Rosenbaum's laboratory under his current NSF support. This parameter remapping effect is a tendency for people's performance of repeated movement sequences to suffer when characteristics of individual movements change from one performance cycle to the next. Experiments will explore the underlying causes, generality, and susceptibility to training of this phenomenon. In addition, the effect will be used to shed light on the building blocks for movements and the rules governing their combination. Another line of experiments will be concerned with another phenomenon that was also recently discovered in Rosenbaum's laboratory. Tentatively called the response switching effect, it is a dramatic reduction in the rate at which people can alternate between vocal and manual responses, compared to the rate at which they can produce manual or vocal responses alone. The phenomenon is surprising, since current theories suggest that it should be possible to produce vocal and manual responses in parallel and therefore very quickly. Several experiments will attempt to identify the source of this effect. A final part of the project will focus on the planning of skilled actions. Experiments will address the question of how people formulate plans for the manipulation of objects. The method will be to record the amount of time that people take, and the sorts of movements they choose to perform, jsut after seeing an array of objects for which an abstractly defined task was given beforehand (e.g., place the object in the container). The model of planning to be derived from the research should be of interest to roboticists and to clinicians who deal with motor disorders.
