Consciousness remains one of the most stubborn mysteries in science. Every day, people cycle between wakefulness and sleep, moving between higher and lower states of awareness, and some deliberately alter their conscious experience further — with psychedelics, or through the induced unconsciousness of anesthesia. A new Michigan Medicine-led study takes a data-driven approach to these altered states and, for the first time, reveals that psychedelics and anesthetics create “mirror image” patterns of large-scale brain organization.

The team, led by Rui Dai, Ph.D., and Zirui Huang, Ph.D., of the Department of Anesthesiology and Center for Consciousness Science at Michigan Medicine, analyzed functional MRI data from participants who had been administered psychedelic compounds — LSD, psilocybin, and nitrous oxide — and compared the results to brain scans taken during natural sleep or sedation with the anesthetic propofol.

Two Drug Classes, Opposite Signatures

“In previous literature, each individual drug’s influence on brain connectivity was analyzed separately. To our knowledge, no one has systematically assessed these two drug classes to compare network organization compared to waking consciousness,” Dai said.

The team found that psychedelics increased functional connectivity — how closely different brain regions work together — while sleep and anesthesia reduced it. The same opposing pattern held for topological integration, a measure of how easily information travels across the brain, and for interaction complexity, or the number of distinct patterns of brain interaction that can be observed.

“Overall, these results mean that during psychedelic states, the brain becomes more globally connected, more efficient in communication and more dynamic, while anesthetic states are the opposite,” Dai said.

A Reliable Fingerprint for Conscious States

The findings offer researchers a reliable, data-driven way to differentiate between conscious states — a longstanding challenge in consciousness science. Zirui Huang, director of the Center for Consciousness Science at the University of Michigan Medical School, said the team turned to drugs specifically because of their known effects on consciousness, even when the underlying mechanisms remain unclear.

“We analyze it using drugs because we know they will affect consciousness in some way, but we don’t know how. The mirror-image effect discovered by this study suggests that the integration, efficiency, and complexity of brain activity may be fundamental to consciousness,” Huang said.

The study was published in Cell Reports (DOI: 10.1016/j.celrep.2026.117830) with additional authors Hyunwoo Jang, Anthony G. Hudetz, and George Mashour, and was funded by the National Institutes of Health.