Table 2.

Results of the yoking procedure. Mean and 95% bootstrapped confidence intervals for the last three sessions of phases 1 and 2 of the study. The reward rates are in rewards per min; the IRT difference is calculated as the difference between the mean reinforced IRT and the mean IRT emitted by each rat in seconds. The letter “y” signifies that the group was yoked to the reward rate obtained in the master ratio group.

Phase	Variable	Schedule
		RR-20 (master)	RPI-y	RR-10
1	Rewards per minute	1.32 [1.16, 1.48]	1.46 [1.27, 1.64]	3.64 [3.34, 3.94]
	IRT difference (sec)	−0.52 [−9.67, 8.63]	−1.77 [−2.26, -1.28]	−6.52 [−7.67, −5.37]
		RR-20 (master)	RPI-y	RI-y
2	Rewards per minute	1.79 [1.53, 2.05]	2.08 [1.76, 2.38]	1.62 [1.39, 1.85]
	IRT difference (sec)	−14.89 [−18.43, −11.35]	−16.53 [−19.77, −13.29]	3.31 [2.45, 4.17]