Figure 2.

Top: Aging effects on two measures of conditioning: % CR and Latency of Peak Response. Younger adults showed a significantly greater number of conditioned responses during acquisition (mean ± standard error, younger: 33.59 ± 3.74, older: 21.68 ± 2.09) (a) and also timed their maximal eyeblink response closer to US presentation (younger: 655.55 ± 7.14, older: 631.34 ± 5.34) (b). These behavioral findings suggest that younger adults condition better than older adults during the concurrent presentation of both delay and trace trials. Bottom: The impact of age on learning rates using % CR and Latency of Peak Response. Since no main effect or interaction involving CS Type was detected, delay and trace trials were collapsed. Older adults failed to show acquisition in the number of their conditioned responses (black circles in 2c) but were able to shift the time of their maximal eyeblink response significantly closer to US onset time relative to pseudoconditioning (black circles in 2d). Younger adults showed learning-related changes on both measures of conditioning (white circles in 2c & 2d). Although there was a significant decline in % CR that accompanied aging, the ability to time eyeblink responses appeared to be preserved in older adults. (Error bars represent ± standard error of the mean; PC = pseudoconditioning)