Table 1.

Average number of omissions±SEM for each test group at each delay.

	Training	Delay 5	Delay 15	Delay 30	Delay 50	Delay 75
5-pellet reinforcer, initial test	0.044 ± 0.027†	0.167 ± 0.079*	0.444 ± 0.111*	0.900 ± 0.161*†	0.611 ± 0.106*†	0.167 ± 0.048†
5-pellet reinforcer, retest	0.176 ± 0.095†	0.353 ± 0.209	1.470 ± 0.777	3.117 ± 0.795*†	3.823 ± 1.367*†	1.412 ± 0.654†
3-pellet reinforcer	0.025 ± 0.018†	0.438 ± 0.133*	0.288 ± 0.139	0.525 ± 0.117*†	0.150 ± 0.051†	0.050 ± 0.025†
Saline-treated	1.428 ± 0.719	2.715 ± 0.993	6.714 ± 1.209*	11.857 ± 2.650*	13.571 ± 3.963*	9.571 ± 2.297*
Cocaine-treated	0.60 ± 0.842	2.80 ± 2.395	7.10 ± 7.340	9.70 ± 9.322*	4.90 ± 4.458†	1.60 ± 1.264†

^*, significantly different from the Training session for the same group;

^†significantly different from saline treated group as same delay length