Response to operant conditioning and yoked controls at 24 h.

Number of average (± SEM) pneumostome openings in 30 min during training (TR) and the test for LTM 24 h later (test @ 24 h) in the CM (Chilton Moor) and TC1 (Trans Canada 1) populations following contingent (white bars) or yoked (grey bars) training. ** = significantly different from TR (P<0.01).