being necessary for learning the structure of the environment necessary to support these predictions. The finding that SPE signals are present in pIPS while subjects are learning state transitions even in the complete absence of reward (session 1 of our task), suggests that this region is involved also in pure state-learning, and not just in encoding value-based representations. Furthermore, it is interesting to note that SPE signal in right pIPS is predictive of subsequent successful choice behavior, whereas the same signal in the left lateral PFC is not. This underlines the importance of the state space representation that is built in the parietal cortex, and suggests that the lateral prefrontal cortex, despite maintaining a similar representation of the SPE, may be concerned with integrating other learning signals too, and therefore does not exhibit the same clear link to subsequent choice behavior.
