Variation in long-term place memory (6 h) as a function of time on platform, spacing, and repetition of acquisition trials (Experiment 2, n = 18). (A) Variation in conditions 1–6 reflect time on the platform (1T-6 sec or 1T-30 sec), massed or spaced encoding trials (T11–T13) separated by 15-sec or 10-min ITI (3T-M or 3T-S), and additional repetition of encoding trials (T11–T16) separated by 15-sec or 10-min ITI (6T-M or 6T-S). (B) Percentage of time in correct zone during T2 probe trials. Note striking effect of trial spacing when three encoding trials are given. Stippled horizontal line indicates chance value for percentage swim time in correct zone. (C) Latencies. Black circles represent retention trial (T2) latencies. Means ± 1 SEM.
