Schematic of receptive field and noise correlation plasticity for trained (red) and untrained (blue) stimuli.

<p>Tectal neurons are represented as circles, circle color marks preferred direction (red, down; blue, up), and dotted lines represent noise correlations. Training with down direction increases and clusters receptive fields oriented toward the trained stimuli and decreases long-distance noise correlations (dashed lines). Receptive fields preferring untrained stimuli (blue) are reduced, and noise correlations to these stimuli are increased on all spatial scales. Note that noise correlations can differ across stimuli and are not necessarily determined by neurons' preferred directions.