The physical correlates of counterfactual choices: from BOLD imaging to dopamine recording
Converging lines of research have begun to identify neural responses related to counterfactual choices that relate to options 'not taken' when compared to actual choices made. Using BOLD neuroimaging and fast-scan cyclic voltammetry in human subjects, we report new results on how dopamine encodes reward prediction errors and counterfactual prediction errors during simple sequential choice. The results raise important questions about the style of encoding for actual errors and counterfactual errors in human brains. The extension of these methods to other neurotransmitter systems will also be discussed.