Figure 3.

Effects of DA receptor manipulations in the medial PFC on probabilistic discounting. Data are plotted in terms of percentage choice of the large/risky lever during free-choice trials by probability block (x-axis). Symbols represent mean + SEM. Gray stars denote a significant main effect (saline vs high dose, p < 0.05). Black stars denote a significant difference (p < 0.05) between treatment conditions during a particular probability block main effect. A, Infusions of the 1.0 μg dose of D₁ antagonist SCH23390 accelerated probabilistic discounting, reducing risky choice. B, In contrast, infusions of the 1.0 μg dose of the D₂ antagonist eticlopride retarded discounting and increased risky choice. C, The D₁ agonist SKF81297 induced a slight, nonsignificant increase in risky choice. D, Infusions of the 10 μg dose of the D₂ agonist quinpirole abolished discounting, decreasing risky choice during the initial block and increasing choice during the final block.