Figure 1.

Prominent theories of dopamine function in value-based choice. (A) The energization account assumes that increased dopamine activation enhances the preference for high benefit–high cost options over low benefit–low cost options (illustrated by a larger font size for the high-cost compared with the low-cost option). (B) Building upon this notion, the accelerator/brake model posits that D₂ receptor (D2R) activation computes the costs that are acceptable for a reward, which determines how strong a D₁ receptor (D1R)–mediated facilitatory signal needs to be to overcome D2R-mediated inhibition. Thus, while both D1R and D2R activation strengthen the preference for high benefit–high cost over low benefit–low cost options, they do so via dissociable effects on processing of benefits vs. action costs. D1R activation strengthens the processing of rewards (larger font size), whereas D2R activation reduces the sensitivity to costs (smaller font size). (C) According to the proximity account, the impact of dopamine on behavior depends on the proximity advantage of the more proximate (in many cases, also the low cost) option over the more distant (often high cost) option. If one option has a proximity advantage over the other, dopamine strengthens the preference for the proximate over the distant reward, as illustrated here. In contrast, if no option possesses a proximity advantage, dopamine favors the high-benefit option in a similar way as assumed by the energization account.