Fig. 5: Responding for intranasal cocaine conforms to behavioral economic principles.

A Individual (thin lines) and averaged (thick line) cumulative records of active lever responding with overlay of the behavioral economics task. The unit price, responses required to obtain 1 mg of cocaine, increased across discrete 40-minute time bins by decreasing the amount of cocaine per delivery (180 – 2 µg/delivery). B Schematic of behavioral economics analysis parameters. Cocaine consumption per time bin (purple circles) and responses (green circles) were recorded. Values for consumption per bin were curve fit (solid black line) to extract measures of intrinsic value (Q₀) and motivation (P_max) for intranasal cocaine. C Demand curves fit to cocaine consumption (mg) per time bin of individual animals. Mean values of Q₀ (D), P_max (E), and elasticity (α) (F) extracted from demand curves. Data represent mean ± SEM; n = 6.