first bite were measured for 3 min following an application
of the CS1 as the immediate conditioning tests. We considered
the latency more than 3 min to be just 3 min for a
statistical treatment. These training procedures were repeated
for some days until the sensory preconditioning was
formed. 2. Massed training procedure: Lymnaea received
the 30 CS1–CS2 paired trials, and then received the 30
CS2–UCS paired trials in one day. The interstimulus
intervals and ITIs were the same as those in 1.. The