As for brain stimulation, TMS devices can be bought for <$10k from ebay. tDCS devices are available for ~$100, though I don’t expect them to have large effect sizes in any direction. There’s been noises of consumer-level tFUS devices for <$10k, but that’s likely >5 years in the future.
Regarding skepticism of survey-data: If you’re imagining it’s only an end-of-the-retreat survey which asks “did you experience the jhana?”, then yeah, I’ll be skeptical too. But my understanding is that everyone has several meetings w/ instructors where a not-true-jhana/social-lie wouldn’t hold up against scrutiny.
The incentives of the people running jhourney are to over-claim attainments, especially on edge-cases, and hype the retreats. Organizations can be sufficiently on guard to prevent the extreme forms of over-claiming & turning into a positive-reviews-factory, but I haven’t seen people from jhourney talk about it (or take action that shows they’re aware of the problem).
As for brain stimulation, TMS devices can be bought for <$10k from ebay. tDCS devices are available for ~$100, though I don’t expect them to have large effect sizes in any direction. There’s been noises of consumer-level tFUS devices for <$10k, but that’s likely >5 years in the future.
The incentives of the people running jhourney are to over-claim attainments, especially on edge-cases, and hype the retreats. Organizations can be sufficiently on guard to prevent the extreme forms of over-claiming & turning into a positive-reviews-factory, but I haven’t seen people from jhourney talk about it (or take action that shows they’re aware of the problem).