Fig. 2.
The dopamine D2-like receptor agonist quinpirole impaired visual reversal learning in the novel VPVD reversal task (n = 7–8 for each group). a Quinpirole at 0.25 mg/kg reduced correct responses on standard A− < B+ trials. b Quinpirole at 0.25 mg/kg increased the number of errors on standard A− < B+ trials across the learning phases (early: < 11 correct in any 30 trials; late: > 19 correct in any 30 trials, but before the criterion of 24 correct). c There was no effect on performance on the B+ > C50/50 trials, indicating intact learning from positive feedback. d Quinpirole dose-dependently impaired performance on the A− < C50/50 trials, indicating impaired learning from losses. Note that rats treated with quinpirole 0.25 mg/kg fail to improve over chance performance on negative probe trials across the 14 days of testing. Graphs show mean ± SEM for each dose and session