Figure 1.

Learning to detect contours in cluttered scenes. (A) Examples of stimuli: Collinear contours in which elements are aligned along the contour path and orthogonal contours in which elements are oriented at 90° to the contour path. For demonstration purposes only, two rectangles illustrate the position of the two contour paths in each stimulus. (B) Average behavioral performance across subjects (percent correct) before and after training for collinear and orthogonal contours presented at trained and untrained orientations. (C) fMRI responses for observers trained with orthogonal versus collinear contours. fMRI data (percent signal change for contour minus random stimuli) are shown for trained contour orientations before and after training on orthogonal versus collinear contours. Adapted with permission from Zhang and Kourtzi (2010).