Figure 4.

Experiential elements of consolidation and maintenance. A, Effect of a delay in testing after P25 [gray background indicates period(s) without testing] on maintenance of enhancement probed at P27 (left), P30 (middle), and P35 (right), and then measured again on P45. B, Summary of thresholds from A measured on P25, P27, P30, P33, and P45. The black line is an exponential with a time constant of 3.5 d. The data in A and B show that any delay in testing after P25 resulted in the decay of enhancement to baseline by ∼P40, which could not be rescued with repeated daily testing. C, Effect of stimulating animals with gratings of fixed SFs from P25 to P45 on enhancement generated with testing SF; contrast thresholds from P15–P25 gratings failed to maintain enhancement, with thresholds in each group falling from maximally enhanced levels at P25 (black bars) to near baseline by P45 (white bars).