Intense Sweetness Surpasses Cocaine Reward
a, Schematic representation of the choice procedure. Each choice session was constituted of 12 discrete trials, spaced by 10 min, and divided into two successive phases, sampling (4 trials) followed by choice (8 trials). S, saccharin-associated lever; C, cocaine-associated lever. b, Choice between levers C and S (mean±SEM) across reward conditions and as a function of time (open circle: S-/C+ condition; closed triangle: S+/C- condition; closed circle: S+/C+ condition). The horizontal gray line at 0 indicates the indifference level. Values above 0 indicate a preference for lever S while values below 0 indicate a preference for lever C. *, different from the indifference level (P<0.05, t-test). c, Sampling (mean±SEM of the last 3 days) of lever S (black bars) and lever C (white bars) across reward conditions. *, different from lever S (P<0.05, Fisher's LSD test after a two-way analysis of variance).