Figure 1.

(A) Example stimuli for perceptual learning. Participants discriminated between two arrays of tilted Gabor elements that differed in their mean orientation (left), mean curvature (middle) or global form (right). (B) Example of the filters that might be used to resolve the task at hand. In some cases different filters may overlap. For instance, in the curvature task the elongated curvature filter overlaps many small orientation filters. Equally, orientation and curvature filters overlap with filters responsible for detecting global form.