Correlation with evening corticosterone level and familiarity discrimination. (A) Cortisol10 pm level was negatively correlated with performance in the novel object discrimination across the whole cohort (r = -0.44, r2 = 0.19, P < 0.01, n = 44). (B) Mean (± s.e.m.) reaction time to novel stimuli. The high cortisol10 pm group were significantly slower at responding to the fourth repeated presentation of a novel object. *Significant group difference at p<0.05. (C) Mean (± s.e.m.) reaction time to familiar object stimuli. There was no significant group difference (P > 0.05). Filled bars indicate low cortisol10 pm group, and open bars indicate high cortisol10 pm group.