Fig. 1. The 30 min training procedure results in a 1-day, but not a 3-day memory. A cohort of snails (N=24) received operant conditioning training of two 30 min training sessions separated by a 1 h interval (Sessions 1 and 2). In the first randomly picked group (N=12), we tested for long-term memory (LTM) 1 day later (Session 3). There was a significant effect between Sessions 1 and 2 (ANOVA; Fisher's LSD protected t-test, P<0.01), demonstrating learning (asterisk). As can be seen, LTM was also demonstrated, i.e. there was no significant difference (NS; Fisher's LSD protected t-test, P>0.05) between Session 2 and the 1-day memory test Session 3, and the significant difference from Session 1 remained (asterisk). The second group of snails, was tested 3 days later (3 days) and LTM was not demonstrated, i.e. there was a significant difference (Fisher's LSD protected t-test, P<0.01) between Session 2 and the 3-day memory-test Session 3, but not between this session and Session 1.