Abstract
"Rats trained to bar press for food were sleep-deprived in increasing 12-hr. periods up to 48 hr. Heart rate was found to increase monotonically with hours of sleep deprivation. Higher heart rates under conditions of high-rate bar pressing appeared to reflect an interaction between cue stimulation and the internal deprivation effects; i.e., heart rate was higher when the cues were more effective in controlling behavior than when less effective, and the effect appeared to be accentuated in the longer (48-hr.) deprivation condition. The results were interpreted as indicating an activating effect of sleep deprivation under conditions of sufficient cue stimulation." (PsycINFO Database Record (c) 2006 APA, all rights reserved)