Figure 1.

Trial time-course (A). An image appeared on the screen. If the animal touched it within 30 s, a 5 s positive feedback appeared (green screen) and a reward (dry pasta beads) was delivered. Otherwise, a 5 s negative feedback appeared (a red screen for an incorrect touch, a gray screen for a no response) and no reward was delivered. Testing conditions (B-D). The animals were tested alone (B), in the presence of an idle companion (C) or in the presence of an active companion doing the same task (D).