Fig. 2. The traditional training procedure and crowding. (A) The traditional training procedure results in LTM, i.e. MT is significantly less than TS1 (^*P<0.01) but not significantly greater than TS2 (P>0.05). Yoked control snails also do not demonstrate LTM as Yoked is not significantly different from TS1 (P>0.05) but is significantly greater than TS2 (P<0.01). (B) A cohort of naïve snails (N=19) were placed in crowded conditions for 24h prior to TS1. In TS2 (separated by an hour, in which the snails were placed in their normal aquarium; N), the snails received a tactile stimulation each time they began to open their pneumostome. Twenty-four hours after TS2, the memory test (MT) was performed. As can be seen, LTM is not formed; that is, when the data were analyzed (one-way ANOVA) we found that while TS2 is significantly smaller from TS1 (^*P<0.01; demonstrating learning and a 1h memory), MT is significantly greater than TS2 (P<0.01) but not significantly different from TS1 (P>0.05). (C) A cohort of naïve snails was placed in crowded conditions for 24h immediately after TS2. A similar analysis as in A was done on these snails (N=22). TS2 is significantly less than TS1 (^*P<0.01) and also the MT (P<0.01). Values are means ± s.e.m.