The acknowledged importance of uncertainty in economic decision making has stimulated the search for neural signals that could influence learning and inform decision mechanisms. Current views distinguish two forms of uncertainty, namely risk and ambiguity, depending on whether the probability...

Curiosity has been described as the "wick in the candle of learning" but its underlying mechanisms are not well-understood. We scanned subjects with fMRI while they read trivia questions. The level of curiosity when reading questions is correlated with activity in caudate regions previously...