Figure 2.

Effects of 20 h extended cocaine access on choice between cocaine and food in rhesus monkeys (n=4). Top abscissae: unit dose cocaine in mg/kg/injection. Top left ordinate: percent cocaine choice. Top right ordinate: percent food choice. Bottom abscissa: 4 h bins of the extended cocaine access session. Bottom ordinate: number of cocaine injections per each 4 h bin. All symbols represent mean±SEM of four monkeys from the last 3-day (days 5–7; 12–14) means of each experimental condition. Filled symbols indicate statistical significance (P<0.05) compared with choice session only conditions.