The effects of counterfactual comparison on learning and reasoning

How humans make choices in uncertain and competitive situations is a key determinant of viability and successful living. Improving those choices requires sometimes encountering undesirable outcomes and avoiding them, eventually even anticipating them in novel situations. Learning depends on making choices, encountering errors and updating evaluations of options. Various models extended from the reinforcement learning framework compared to human behavior describe in part how individuals heterogeneously make choices. To peer into the components of these mechanisms, strategic games that emulate real-world situations provide measurable and manageable environments in which to examine slight differences in choice behavior among different people. Such differences may be endogenous to participants (e.g. age or learning disposition) while others derive from external events (e.g. emotional induction or brain stimulation). We contrasted such behavior in three situations involving learning or competition, leveraging differences in age, emotional induction and brain stimulation. We aimed to describe the variations in choice behavior across these differences and investigated, when possible, how prior conditions generated a transfer of learning from one domain to another. The work here builds on recent investigations of neural mechanisms underlying choice behavior during strategic or competitive interaction.