The study by Rodolfo Llinás and Urs Ribary investigates the 40-Hz oscillation in the human brain during wakefulness and rapid-eye-movement (REM) sleep, as well as its absence during delta sleep. Using magnetoencephalography (MEG), they recorded magnetic activity from five healthy adults. The results show that 40-Hz coherent magnetic activity is prominent during wakefulness and REM sleep but significantly reduced during delta sleep. This 40-Hz oscillation is reset by sensory stimuli in the awake state but not in REM or delta sleep. The 40-Hz oscillation in REM sleep exhibits a fronto-occipital phase shift with a maximum duration of about 12-13 milliseconds. The authors propose that this 40-Hz oscillation is a correlate of cognition, likely resulting from coherent resonance between thalamocortical-specific and nonspecific loops. The specific loops provide the content of cognition, while the nonspecific loop facilitates temporal binding, enabling the unity of cognitive experience. The findings suggest that consciousness is an intrinsic event modulated by sensory activity, and that dreaming may be characterized by an increased attentiveness to an intrinsic state, where external stimuli do not perturb the intrinsic activity.The study by Rodolfo Llinás and Urs Ribary investigates the 40-Hz oscillation in the human brain during wakefulness and rapid-eye-movement (REM) sleep, as well as its absence during delta sleep. Using magnetoencephalography (MEG), they recorded magnetic activity from five healthy adults. The results show that 40-Hz coherent magnetic activity is prominent during wakefulness and REM sleep but significantly reduced during delta sleep. This 40-Hz oscillation is reset by sensory stimuli in the awake state but not in REM or delta sleep. The 40-Hz oscillation in REM sleep exhibits a fronto-occipital phase shift with a maximum duration of about 12-13 milliseconds. The authors propose that this 40-Hz oscillation is a correlate of cognition, likely resulting from coherent resonance between thalamocortical-specific and nonspecific loops. The specific loops provide the content of cognition, while the nonspecific loop facilitates temporal binding, enabling the unity of cognitive experience. The findings suggest that consciousness is an intrinsic event modulated by sensory activity, and that dreaming may be characterized by an increased attentiveness to an intrinsic state, where external stimuli do not perturb the intrinsic activity.