A. Before categorization training, Monkey H passively viewed eight directions of coherently-moving dot stimuli (Fanini and Assad, 2009).
B. For direction-selective neurons, the ranked activity evoked by each direction is plotted during the sustained visual response (200-600 ms post-motion onset) as the monkey passively viewed the stimuli. Directions are color-coded as in the motion categorization task in Fig. 1, where 6 indicates the highest activity, and 1 indicates the lowest activity. Two directions that fell along the category boundary were excluded.
C. The ranked activity for motion direction-category selective neurons recorded from Monkey H following the categorization training, replicated from Figure 3A, right panel.