Computational model.

<p>A) Subjects are uncertain as to the true goal location among two possibilities and expect their beliefs to vary over time. In this case, the subject marginally favors the leftward target at movement onset (<i>p</i>₀ > ½). During movement, this belief may either strengthen (solid line) or reverse (dashed line). B) When targets are nearby, the optimal course of action is to bias movement only slightly towards the more likely target, allowing greater flexibility later in the movement. C) When targets are widely separated, an intermediate movement is less advantageous. Instead, the optimal course of action is to commit to the more likely target from the outset. D) Predicted initial reach direction (normalized so that 0 corresponds to initial target, and 1 corresponds to the post-jump target) is plotted for a variety of target separations as a function of the initial belief state <i>r</i>₀. E) As D), but for a model that uses an asymmetric cost function (see <a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1004171#sec011" target="_blank">Methods</a>).