Fig. 4. Snails receiving a CR/PR training schedule are more resistant to extinction
than snails receiving a PR/CR schedule. (A). Two continuous reinforcement (CR)
45 min training sessions on day 1 followed by two partial reinforcement (PR)
training sessions on day 2 produce a long-term memory that is resistant to
extinction. On the day following the PR schedule of training (day 3), the
snails received two extinction training sessions. When given the test for
extinction on the following day (day 4), extinction was not observed (i.e.
long-term memory was present). That is, the number of pneumostome openings in
the extinction test session was not significantly different from that in the
last PR session (P>0.05). (B) As in A except that this naïve
group of snails received the PR schedule first (day 1) followed by the CR
schedule (day 2). Extinction training on day 3 was sufficient to produce
extinction. That is, the number of pneumostome openings in the extinction test
session on day 4 was significantly different from that in the the last CR (day
2) training session (P<0.01). Values are means ± S.E.M.
(N=20).
