Emergence of bias for inferred reaches in the DNF model.

<p>The figure shows two snapshots of the activation patterns in the model during a single PMG trial. (A) During the memory period, after the presentation of a spatial cue, an activation peak has formed in the association field. Its position along the spatial axis reflects the direction of the spatial cue, while its location along the second dimension is unspecific and spans both context-sensitive regions (shown as outlines in the association field, green for direct, white for inferred context). The region that shows preference for the inferred context is substantially larger than the direct-context region, due to the high proportion of inferred trials during training. This region projects to the location in the motor preparation field which codes for a reach in the direction opposite to the spatial cue. The competitive interactions in the motor preparation field further amplify this stronger input that supports the inferred reach. (B) When a context signal for a direct trial is given at the end of the memory period, the context input induces a shift of the peak in the association field: It is pulled almost completely onto the region specific for the direct context with which it partly overlapped. The input to the motor preparation field changes accordingly, leading to a switch in that field's activation pattern and a stronger activation of the ‘direct’ reach direction.