Paradoxical pharmacological dissociations result from drugs that enhance delta oscillations but preserve consciousness

Low-frequency delta-band neural activity is typically associated with loss of consciousness and cortical down states, especially when diffuse and high amplitude. However, several classes of pharmacological agents—including antiepileptic drugs, GABA B receptor activators, acetylcholine receptor blockers, and psychedelics—can produce neural activity resembling cortical down states while participants remain conscious. Among these substances safe for healthy volunteers, some may serve as valuable research tools for determining which neural activity patterns are sufficient for consciousness or its absence.

Study at a glance

Abstract

Abstract Low-frequency (<4 Hz) neural activity, particularly in the delta band, is generally indicative of loss of consciousness and cortical down states, particularly when it is diffuse and high amplitude. Remarkably, however, drug challenge studies of several diverse classes of pharmacological agents—including drugs which treat epilepsy, activate GABA B receptors, block acetylcholine receptors, or produce psychedelic effects—demonstrate neural activity resembling cortical down states even as the participants remain conscious. Of those substances that are safe to use in healthy volunteers, some may be highly valuable research tools for investigating which neural activity patterns are sufficient for consciousness or its absence.