but only the appropriate sipper entered the chamber. The tube was available for ≈10 s. Each trial was separated by a 20- to 180-s intertrial interval (ITI; 90 s on average; randomized order). A total of 40 trials were conducted for 5 out of 7 d/week (weekdays) for three weeks (15 total sessions) before surgery. Water sessions were identical to alcohol sessions except the sippers contained water. During water sessions, a tube containing 10% (v/v) alcohol was present outside the fluid delivery port to ensure that the presence or absence of the alcohol odor did not predict alcohol availability/unavailability.
