Have you ever had a psychedelic experience? Or in Jimi Hendrix’s infamous words: Are you experienced? What began as an abstract question of life experience in 1967 has continued to bother researchers for years. After all, what is a psychedelic experience? And how do I know I’ve had one? While life provides a subjective test to answer the question (like an orgasm, when you know, you know), this method has left scientists unsatisfied and unable to verify the suggestion. That is, until recently.
Researchers from the Sackler Centre for Consciousness Science, the Psychedelic Research Group, and the Auckland School of Pharmacy have recently come together in an attempt to pin down the measurable difference in brain activity during a so-called psychedelic experience, namely one brought on by either lysergic acid diethylamide (LSD), psilocybin (magic mushrooms) or ketamine.
“Here, we sought to test the hypothesis that three different psychedelic drugs (psilocybin, LSD and sub-anaesthetic ketamine), known to produce unusual altered states of consciousness, characterised by rich phenomenal content, would yield scores of signal diversity exceeding those for normal waking consciousness.” - Increased spontaneous MEG signal diversity for psychoactive doses of ketamine, LSD and psilocybin: Schartner, Carthart-Harris, Barrett, Seth, Muthukumaraswamy.
By carefully measuring brain activity in participants that were either given psilocybin, LSD, ketamine, or a placebo, researchers were able to identify “increased spontaneous signal diversity” in the brain’s of those that had been given either of the three psychedelic drugs, the strongest of which being LSD (an anecdote this writer can confidently cosign after several research projects).
“We have demonstrated, for the first time, that measures of neural signal diversity that are known to be sensitive to conscious level, are also sensitive to the changes in brain dynamics associated with the psychedelic state.,” - Increased spontaneous MEG signal diversity for psychoactive doses of ketamine, LSD and psilocybin: Schartner, Carthart-Harris, Barrett, Seth, Muthukumaraswamy.
By identifying increased global neural signal diversity for the psychedelic state, researchers now hypothesize that the “psychedelic experience” lies above the conscious states of wakeful rest and REM sleep in terms of neural signal diversity. To get back to Jimi Hendrix, further research will be needed in an attempt to pin down the properties of “richness” of conscious states. This will allow scientists to differentiate experiences brought on by the psychedelic, and those brought on by other emotional responses, like say, a guitar solo.
Study source: https://www.nature.com/articles/srep46421#author-information
“Increased spontaneous MEG signal diversity for psychoactive doses of ketamine, LSD and psilocybin: Schartner” Carthart-Harris, Barrett, Seth, Muthukumaraswamy