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

A mini-review reflects on the use of pharmacological drug challenges to explore EEG delta oscillations which persist despite the preservation of human consciousness. 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.

Automated summary

Pharmacological drug challenges are used to study the phenomenon of EEG delta oscillations persisting despite consciousness. Some drugs induce neural activity resembling cortical down states while participants remain conscious. These drugs can be valuable research tools for investigating the neural activity patterns necessary for consciousness.