Figure 5. Differences in motor function between adult and aged baboons on the object retrieval task with barrier detour. (A) Representative images of the baboon performing the object retrieval task. The baboons had to learn to by-pass the transparent barrier and reach for the reward through the open side of the box. (B) On day 1, aged baboons took significantly longer to initiate a response after the screen was raised compared to adult baboons (Two-way ANOVA, ** p<0.01). No significant differences were seen in (C). Reach number. (D) Barrier reach. (E) Perseverance (except day 6) and (F) Success. (G) Aged baboons committed significantly more errors on day 1 of the task compared to adult baboons (Two-way ANOVA, *** p<0.001). No hand preference (H) or hand bias (I) was observed.