Attention and prism adaptation

For both lateral displacement and rotation of the visual field, visual adaptation was reduced when subjects were required to perform a secondary cognitive task simultaneously with the primary exposure task of walking about hallways. Interference appeared to be independent of walking rate and occurred when the cognitive task was either mental imagery or mental arithmetic. A tentative model is presented which assumes that the direction of guidance between sensorimotor systems (e.g., eye-head and hand-head) is set by limited capacity higher level processes (attention) that differentiate the set of sensorimotor subsystems into guiding and guided subsets in accordance with a task's particular demand structure. Perceptual discordance and consequential adaptive recalibration of afferent functions are localized in the nonguiding system(s). If limited central-processing capacity is required to perform a secondary cognitive task simultaneously with the exposure task, directional linkage between discordant systems is degraded and adaptive recalibration reduced.