Fig. 6. Effects of inter-trial interval. (A) Stimulus schedules (see Fig. 1C for key to shading). Five groups of crickets were subjected to two sets of differential conditioning trials with inter-trial intervals (ITIs) of 30s (group 1), 1 min (group 2), 2 min (group 3), 5 min (group 4) and 10 min (group 5). (B) Performance indices of groups 1-5 (N=39, 40, 39, 45 and 47, respectively) 2 h, 1 day and 4 days after training. Values are means + S.E.M.