Inflexible habitual decision-making during choice between cocaine and a nondrug alternative

a Experimental timeline. b Mean percent of cocaine choices (±SEM) as a function of testing sessions. The horizontal dashed line at 50% represents the indifference level. * Different from the indifference level (p？<？0.001, t-test). c Distribution of individual preference scores averaged over the last three choice sessions. d Mean latency (±SEM) to select the cocaine or water option during sampling or choice trials. *Different from cocaine sampling latency (p？<？0.001