approach used here would provide a computational account of the means by which such attention is allocated on a trial by trial basis, and of how those allocations change as a function of learning and experience. Our findings would then be novel evidence about the mechanisms underlying this form of learning. However, the appeal of this account and other accounts dependent on salience is weakened by the observation that the SPE is only a, possibly minor, but very specific subcomponent of a general surprise signal, which we would expect to be dominated by reward-induced salience signals: unexpected delivery or omission of reward at the end of a trial. Our finding that our model-based SPE provided a significantly better account for the BOLD signal in pIPS and latPFC than an unsigned RPE (Figure S4) provides direct evidence for the distinction between these two signals.
