Table 3.

Means (delta-method robust standard errors) for accuracy (selection of the stimulus with 80% “correct” feedback) during stage 1 training

Variable	Group	Dose
		placebo	caffeine 150	caffeine 300	d-amph 20
accuracy *	control	0.56	0.55	0.56	0.61
		(0.02)	(0.03)	(0.02)	(0.02)
	cocaine	0.54	0.56	0.58	0.56
		(0.01)	(0.02)	(0.02)	(0.02)

(acquisition phase) on the probabilistic feedback selection task across placebo, 150 mg caffeine, 300 mg caffeine, and 20 mg d-amphetamine doses. Data are were collected approximately 75 min after dosing, and are shown separately for the control and cocaine-dependent groups

^*p < .05 main effect of dose, see text for details