How Do Psychedelic Drugs Work On The Brain?

An interesting video by Robin Carhart-Harris explaining the effects of psilocybin on the brain.

One of the primary effects of psilocybin (and meditation) is to decrease the activity of the Default Mode Network (DMN), an area of the brain that usually receives about 40% more blood than other areas.  The DMN, something like the wandering mind, involves activities such as:

• self-reflection
• complex mental imagery
• mental time travel
• theory of mind (thinking about other's thoughts)
• metacognition (thinking about thinking)

Plausibly, meditation should be designed so as to lean away from these types of things.

In addition to decreasing DMN activity, the integrity of DMN and other networks is decreased.  This may be related to feelings of being "fragmented" or a disintegration of self, and may explain distortions in time perception.

EEG amplitudes are decreased, particularly alpha, in part because of a decrease in overall coherence and synchrony.  There is more instability, more chaos or entropy.  Since the waves aren't aligned, they can't get reach the same amplitudes.

However at a network level, say between the DMN and TPN (task) networks that are usually more anti-correlated, these actually become more similar in activity.  The integration of the mind at this level might relate to feelings of oneness.

The decreases in the DMN are correlated with intensity of effects, ego disintegration, decrease in alpha power, as well as an increase in "magical thinking" and speculative ("impetuous") inference.

Pain and Anxiety reduction from Meditation

Article describes:

... an experiment that involved applying unpleasant electric stimuli to a group in a meditative state and to a control group with a similar healthy lifestyle, each group comprising 17 volunteers. All test subjects were in an fMRI scanner when the stimuli were applied.

The experiment produced surprising results, as it revealed that mindfulness practitioners were able to reduce pain perception by 22 percent and anticipatory anxiety by 29 percent during a mindful state.

Acid Test: LSD, Ecstacy, and the Power to Heal

Interview with Tom Shroder, author of Acid Test: LSD, Ecstacy, and the Power to Heal He explains the process of MDMA assisted psychotherapy along with the history of MDMA's rise from party drug to harbinger of hope.

Psychedelics in American Religious Experience

Psychedelics in American Religious Experience, some background relating the Pahnke Good Friday / March Chapel experiment and a survey about what percentage of the general population are having mystical experiences by way of psychedelics.