(A) All rats showed low levels of responding during preconditioning when neutral cue pairs were presented. There was no effect of cue or group. (B) During reward conditioning, all rats (grey, eYFP; green, NpHR) showed higher responding to the rewarded cue B (solid lines) than to the non-rewarded cue D (dotted lines). (C) During the probe test, responding to A was higher than to C in control rats (eYFP, left, grey), but not in OFC inhibition rats (NpHR, right, green). (D) Scatter plot of A versus C responding during the probe test. To the extent that responding to A and C are equal, points should congregate along the diagonal. Points below the diagonal indicate A>C responding and therefore evidence of preconditioning.