Applied Experimental and Human Factors Brown Bag

Daniel Mcconnell

Title: Dynamic discontinuities in a discrete aiming task

Abstract: It is well established that performance in a reciprocal aiming task can be modeled with oscillatory dynamics. When the task is easy, movements are harmonic, exhibiting a limit cycle dynamic. When the task is difficult, movements deviate from harmonicity, and instead exhibit a fixed point dynamic. These two dynamic patterns are thought to reflect two different modes of movement control and organization, reflecting the differential influence of speed and accuracy constraints. It is less established how well the dynamical systems approach applies to discrete aiming movements. Some studies have shown deviations from harmonicity in difficult discrete movements, but the differential influences of speed and accuracy constraints have not been controlled. In the current study, we systematically manipulated target size and movement distance in a discrete pointing task and used kinematic analyses to study variations in harmonicity as a function of these constraints.