FIGURE 1.

(Left) Anterior insula (aIns) activation correlates with surprise, defined as the difference between the size of the prediction error (PE) and the expectation of this size (risk). Results from a card game where potential reward profiles, including expected reward and reward variance (risk) change upon two consecutive draws of cards. (Right) Plot of neural activation as a function of risk PE. For control, activation under zero risk, and hence, zero risk PE is shown as well, but not included in the regression line (dotted line) (Preuschoff et al., 2008) (Reproduced by permission #4422210891259).