This is really fascinating. I think it's entirely possible that such extra "dimensions" (for want of a better term) exist.
However, to play Devil's advocate for a moment - it occurred to me that such reptilian visions might be conjured up by an over stimulated visual cortex. We are evolved over millions of years, and our distant ancestors well have developed brain circuitry to detect and avoid reptilian creatures (crocodiles, large snakes etc). Ancient brain circuitry such as this getting triggered during the altered state could be responsible for the consistency of the visions.
This is really fascinating. I think it's entirely possible that such extra "dimensions" (for want of a better term) exist. However, to play Devil's advocate for a moment - it occurred to me that such reptilian visions might be conjured up by an over stimulated visual cortex. We are evolved over millions of years, and our distant ancestors well have developed brain circuitry to detect and avoid reptilian creatures (crocodiles, large snakes etc). Ancient brain circuitry such as this getting triggered during the altered state could be responsible for the consistency of the visions.
Yeah spiders are frequently seen with a Benadryl overdose. Here's a look at it:
https://www.reddit.com/r/askscience/comments/pbphb/why_does_diphenhydramine_in_high_doses/
Might be similar.
Yikes! I'll remember not to down a pint of Benadryl anytime soon... :D