Fig. 4: Experiment 3 results.
From: Demand for heroin in rats: effects of non-drug alternative substitutes and complements
a Demand curves fit to group mean consumption (IHS transformed) of saccharin reinforcers (left lever) across the prices (fixed ratios) of heroin on the right lever. b Mean (±SEM) essential value for the two groups. Circles and triangles represent individual female and male rats, respectively. c Mean (±SEM) heroin Q0. *p < 0.05. d Mean (±SEM) consumption of heroin infusions (right lever) as a function of the price of saccharin on the left lever in the Saccharin With Heroin group. The dotted line indicates that heroin was always available on the right lever on an FR-6 schedule. e Mean (±SEM) of the slopes of the linear regression best fit lines relating log heroin consumption to log price of saccharin in the Saccharin With Heroin group. The dashed horizontal line at 0.2 represents the threshold for substitution. *p < 0.05, ***p < 0.001.
