Figure 3.

The magnitude of the decline in activity-based sleep efficiency during the week over the course of the study was calculated as the difference between the sleep efficiency on the last 2 days prior to self-administration (Sun and Mon) and the last 2 days of cocaine use (Thursday and Friday). Open and closed symbols reflect data points for individual subjects over 3 week periods. Each bar represents the average (±SEM) of the all subjects (n=6 with the exception of the last 2 bars on the right, which represent the average of 4 subjects). BL1 and BL2 refer to consecutive periods during the baseline condition which is followed by subsequent 3 week periods during cocaine-self administration.

* Significantly different from last 3 weeks of baseline: P<0.05 (n=6);

# P=0.079 versus last 3 weeks of cocaine self-administration (n=4).