Fig. 2. A continuous reinforcement (CR) schedule results in learning and long-term memory that persists for 2 but not 3 days. (A) A group of 20 naïve snails received two 45 min CR training sessions with a 1 h interval between the sessions. Learning occurred (ANOVA, F_19,1=51.99, P<0.001; session 2 was significantly less than session 1, P<0.01), and a long-term memory had been formed when tested 2 days later [the memory test session was not significantly different from session 2 (P>0.05) but was significantly different (P<0.01) from session 1]. (B) As in A, except that long-term memory was tested 3 days later and N=19. Learning occurred (ANOVA, F_18,1=47.32, P<0.001; session 2 significantly less than session 1, P<0.01), but no long-term memory was formed [the memory test session was significantly different from session 2 (P<0.01) and was not significantly different (P>0.05) from session 1]. Values are means + S.E.M.