Figure 3. Simple discrimination task reveal deficits in learning. (A) Illustration depicting the set up for the simple discrimination task. One shape (green check mark) is associated with delivery of reward during the task. (B) Daily performances of simple discrimination task showed that adult baboons learned to identify the correct shape associated with rewards and performed consistently better than aged baboons. The difference in performance on the task from day 6 was statistically significant (Two-way ANOVA, * p<0.05). (C) The adult baboons overall performed significantly better compared to the aged baboons on the task (*** p<0.001). (D) The aged baboons took longer to reach criterion (** p<0.01). (E) Graph depicting the response latency of adult and aged baboons during each day of the task. (F) The latency to respond was significantly longer in aged baboons compared to the adult subjects (** p<0.01). (H and G) Quantitative analysis of pellet collection latency between adult and aged baboons showing no significant differences.