Right up front, when discussing his background, it sounds like Griffiths refers to a vipassana "arising and passing" event (stereotypically a big experience of love, bliss and lights) that occurred at a Siddha meditation retreat of some kind. He refers to an opening up of a sense of awe and wonder, a "deeply moving" experience that led him to read up on spirituality to understand "what the hell happened to me."
He also refers to the famous 1962 Good Friday Experiment by Walter Pahnke at Harvard (under thesis advisors Timothy Leary and Richard Alpert aka Ram Dass), where a high percentage of those dosed with psilocybin had profound religious experiences. Roland considered his 2006 study to be a replication of Pahnke's experiment, albeit with tighter controls, and as somewhat of a skeptic he was blown away by the results, with high percentages ranking the experience as one of the most important of their life. His surprise at the results stems from his background as a researcher with 40 years of experience at interviewing subjects on various types of other psychoactive drugs, uppers and downers, etc. Clearly psychedelics are a very special class of drug.
They used the Hood Mysticism Scale which lists the following as aspects of traditional spontaneous mystical experiences:
- unity, interconnectedness, oneness, merging
- deep reverence or sacredness
- noetic, an "authority" of the experience being more real or true than everyday life
- positive mood, heart opening, peace & tranquility
- time and space collapse into the present moment
He was very excited ("kid in a candy store") by the prospects for future research, as demonstrating that the psilocybin effects seem to be nearly identical to traditional spontaneous experiences means they can use the drug to prospectively research the effects of the experience, looking at various areas of the brain, drug interactions, personality variables, genetic influences, etc.
As a result, much research is in the offing. He plans to study the effect of psilocybin on prospective meditators. Another interesting study will be to look at long term established meditators, their experience on psilocybin, and this will be done in conjunction with Richard Davidson (for neuroimaging) who did the well known paper showing high levels of gamma and gamma synchrony in long term meditators. There will be a study for cancer patients to see if a psilocybin experience can help those suffering from death related anxiety. And research to gauge the effects of a psilocybin experience in conjunction with drug rehabilitation.