Figure 2.

Results of object discrimination training in Experiment 1. (A) Cumulative frequency plots show the percentage of young (n = 20) and aged (n = 10) rats that achieved the required criterion of ≥81.3% correct responses across training sessions with standard object pairs. (B) Cumulative frequency plots show the percent of all young and aged rats that reached criterion across training sessions with the distinct and similar LEGO® object pairs. (C) Mean (±SEM) number of incorrect responses made by young and aged rats prior to achieving criterion performance on standard and LEGO® object discriminations, collapsed across all training days. Both age groups completed more incorrect trials in learning the similar pair than in learning the distinct pair (p’s < 0.001). Aged rats were no different than young in number of trials to learn the distinct discrimination (p = 0.23), but required a greater number of trials than young to reach criterion on the similar pair (p < 0.002). ** p < 0.01, *** p < 0.001.