Figure 3

Increase of tonic dopamine level enhances social learning. (A) Prior to each exposure session, the naïve observer gerbils were given an injection of a dopamine receptor agonist (6 males; age = 100.3 ± 12 days; see “Methods” section for details). After 15–20 min of recovery, the exposure session began (left) with the demonstrators (age = 139 ± 5.2). No drug was injected during the practice sessions (right). (B) Similar to A, except that saline was injected to the observers (5 males; age = 104.3 ± 10.7) prior to each exposure session (left) with the demonstrators (age = 163 ± 5.4). No drug was injected during the practice sessions (right). (C) Individual and mean ± SEM of the overall number of Go and Nogo trials performed by the observer gerbils during the practice sessions (agonist-injected observers in green and saline-injected observers in blue). (D) Individual and mean ± SEM of the performance d′ of the observer gerbils as a function of practice sessions.