Mean minute by minute diastolic blood pressure (left panels), systolic blood pressure (middle panels), and heart rate (right panels) on Days 1, 9 and 18. During the first (i.e., pre-session) and last (i.e., post-session) 20 minutes of each session access to the levers was blocked and no infusions were administered. Variance estimates were omitted for brevity; descriptively, the vast majority of SEMs ranged from 1.5–4.0 mmHg for both DBP and SBP and from 5–15 bpm for heart rate.