Table 1.

Timing of passive infusion days for each group in each experiment

	Days in the Passive Infusion Phase
Exp. 1	1	2	3	4	5	6	7	8	9	10
Massed (n = 15)						P1	P2	P3	P4	P5
Spaced (n = 15)	P1		P2		P3		P4		P5
Exp. 2	—	—	—	—	1	2	3	4	5	6
Immediate (n = 11)	—	—	—	—		P1	P2	P3	P4	P5
Delay (n = 11)	—	—	—	—	P1	P2	P3	P4	P5
Exp. 3	—	1	2	3	4	5	6	7	8	9
Master (n = 7)	—	P1	P2	P3	NCC1	P4	NCC2	P5	NCC3	P6
Yoked (n = 6)	—	P1	P2	P3	NCC1	P4	NCC2	P5	NCC3	P6

Note: P1-6 indicates the days on which passive infusions were delivered to each group. Since the total number of days in the passive infusion phase differed across experiments the days with passive infusions have been shifted to emphasize the between-experiment comparison with respect to the delivery of the final passive infusions relative to the start of the self-infusion phase. The Spaced group (Exp. 1) had the same interval between the last passive infusion and the start of the no-choice phase as the Delay group (Exp. 2). Similarly, the Massed group (Exp. 1), Immediate group (Exp. 2), and Master and Yoked groups (Exp. 3) had the same interval between the last passive infusion and the start of the no-choice phase. “—” indicates days that were not included in Experiments 2 and 3. On days with no symbols or letters, rats remained in the chambers with food and water available but no infusions were delivered. In Experiment 3, NCC1-3 refers to days that were No Choice self-infusion days for the Master group. Ethanol intake of individual rats in the Yoked group was Yoked to that of the individual rats in the Master group on these days. Thus, the NCC days were another variant of passive infusion days for the Yoked group.