Fig. 2.

Time spent head-poking into the food magazine during cue presentation at the end of the training phase. The data shows the mean cumulative time (mean ± s.e.m.) subjects spent with their head in the food magazine over the 10 s intervals preceding reward outcomes, pooled from the last three sessions of training. During this time reward-predictive signals indicating a 100%, 50% or 0% chance of reward were presented (corresponding to S⁺, N1 or N2, and S⁻, respectively). n = 24