Prism 5.0a

Differences in MAD following saline control and drug administrations were analyzed using a repeated measures one-way ANOVA (GraphPad Prism 5.0a for Mac, San Diego, CA). Changes from saline in the proportion of large alternative choices at each delay for each cocaine dose were analyzed using a repeated measures two-way ANOVA (Drug X Delay; GB Stat, Dynamic Microsystems, Inc, Silver Springs, MD). Significantly different gradients were analyzed post hoc using Tukey's LSD protected t test to determine significant changes in impulsive choice at each delay value. The 15 mg/kg dose of cocaine disrupted behavior (e.g., stereotypy and anorexic behaviors are common following such large doses of cocaine), which resulted in some missing data points, mainly at the 24-s delay. Similar to previous research (e.g., Evenden and Ryan 1996 (link)), these missing data points were replaced with group mean values to conduct statistical analysis. The AUC calculations and Pearson's correlational coefficients between various measures were assessed using GraphPad Prism (5.0a) for Mac. To quantify the percent change in baseline AUC (decrease in large preference) across the cocaine dosing conditions, AUCs of the cocaine gradients were calculated using the baseline proportion of large choices at the 0-s delay.

Differences in donor characteristics between groups were tested using a Mann Whitney U or chi squared test where applicable. A logistical regression was performed to test differences in cofactor ratios and DRI between groups. Analysis was performed using Prism 5.0a for Mac OSX (GraphPad Software, La Jolla, CA) and MATLAB (MathWorks, Natick, MA). Data is presented as median (Q1–Q3) unless otherwise noted.