Fig. 2.

Mean nose-pokes during CS presentations are shown as a function of the 6 blocks of trials conducted on each of two days at timepoint 1 for (A) the middle-aged cohort and (B) the younger-adult cohort. Solid black lines denote rats conditioned at the 2 s trace interval and broken grey lines denote rats conditioned at the 10 s trace interval. Triangles denote day 1 conditioning and X symbols denote day 2 conditioning. Error bars represent the standard error of the mean. Asterisks indicate a significant difference between day 1 and day 2 responding for the 2 s trace conditioned groups, *p < 0.05, **p < 0.01, ***p < 0.001.