Effects of sleep deprivation on cortical activation during directed attention in the absence and presence of visual stimuli

► Preparatory attention prior to stimulus appearance indexes endogenous attention. ► Preparatory and stimulus-driven attention were tested. ► After a normal night of sleep, baseline shifts occurred when attention was deployed. ► Sleep deprivation attenuated baseline shifts signifying loss of endogenous attention. ► Sleep deprivation reduced responses to ignored in addition to attended stimuli.