Neural activity and task behavior in normal and disconnected networks.

<p>(A) Flexible switching of behavior through the bottom-up modulation process induced by sensory perturbation. (B) Outwardly normal behavior with intermittent increases of prediction error and aberrant modulation of intentional states (arrows) induced by simulated mild functional disconnection in the hierarchical network. (C) Cataleptic and (D) stereotypic behavior induced by the severe disconnection. Arm: 4 dimensional joint angles. Vision: relative position of the object (<i>x</i>-<i>y</i> axis). A long sideways rectangle indicates the single unit activity over many time steps. Colors of rectangles indicate activation level (cf. color bar). Low and High indicates activity of units in the lower level and the higher level of the network. Intent indicates the activity of parametric bias (PB) units in the higher level, whose activity corresponds to the top-down intention for the task behavior (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0037843#s4" target="_blank">Methods</a>). Pred error indicates prediction error accumulating for the past 25 steps.