I'm not sure if it has, at least not rigorously. I've seen various research quoted in several books, but I tend to ignore those sections because "research" can pretty much come up with any conclusion depending on who's paying. Plus there's little point accepting the conclusions without investigating the methodologies, participants, etc. for which I have neither the time nor inclination. All my "research" is based on trying to experientially validate the experiences for myself.

I'd love to see rigorous research done on this, and I'm sure over time it'll happen. But first, I think there needs to be a general increase in awareness of this phenomenon, certainly in the West. While we've leapt on the meditation bandwagon, it's far less common knowledge that these practices traditionally were focussed towards a specific "end-game", i.e. they are intended to lead to certain definite, reproducible outcomes, rather than being practiced as techniques in their own right ad infinitum.

It seems to me as if the "first generation" of Western practitioners went to the East around the 60s and the majority came back with superficial knowledge and someone else's culture ("let's do all this cool exotic stuff people..."). Now, slowly and gradually, more Westerners are discovering the stuff that the first generation didn't bring back, and are having profound, authentic experiences for themselves. One benefit of this should be an increase in the clarity of teachings since different cultures have their own metaphors, language and mental models that can be used to convey meaning. Western teachers should be able to strip out the Eastern dogma and superstition and leave only those practices that do actually aid or accelerate the process (and incidentally describe the roots of Western religious dogma and "morals" as well, since Kundalini is alluded to in Christianity, just less explicitly and couched in different terms. If you can ignore the author's enormous ego, Electrical Christianity explains all, also on Kindle if you're interested).

One interesting thing to note is that there is generally broad, cross-cultural and cross-temporal agreement of some of the subjective experiences that result from these practices and Kundalini awakenings. So while looking purely from a physiological perspective would certainly be interesting, it seems that experiences are almost always accompanied by "spiritual" experiences (much like hallucinogens), often involving:

* a dissolution of the ego (the mental narrator/individual personality)
* a greater sense of connection, deep feelings of love and altruism
* common imagery/symbology
* heat, feelings of electricity/"energy", and points of high electrical/energetic conductivity that can be perceived as lights, commonly called "chakras"
* that we are all part of a single, pure consciousness out of which everything else arises. Nothing else fundamentally, permanently exists.

Jung came up with his "collective unconscious" as a result some of his own experiences.

So given these experiences suggest a very different world-view to the prevailing Western one (that we are in fact "spirits" with material bodies vs material bodies with some emergent property called consciousness), could it be possible to really understand this process objectively? It would appear that the conscious subject - indeed consciousness itself - is inherent in the process. Western science more or less proceeds from the standpoint of "if you can't poke it or work out its physical foundation, it doesn't exist", while here we have something diametrically opposite that says the physical only exists because of consciousness (BTW I may be way off here but doesn't Quantum Theory stipulate something similar - the result of a quantum probability isn't decided until it's observed, so the observer is required for the uncertainty to collapse to a specific state? Ignore me if I'm wrong, I'm not a physicist).

So anyway, back to your point. Some resources out there do contain what comes across as subjective, superstitious rubbish, but perhaps for the reasons above (i.e. they may be recounting experiences that are subjectively real, but which seem so fantastical and are so far removed from our normal day-to-day experiences they put people off this whole subject). And to be clear, some are legitimately, complete drivel. However, there are a few people putting stuff out in a much more neutral manner, more like "try this and see what happens", "what if you add on this extra practice?", etc. The latter approach provides fewer points of resistance to the Western, science-orientated mind, and better yet, actively engages you as the scientist. Yogani at aypsite.org is one such author.

Based on my own experiences, I believe science will catch up in due course. I'm pretty open to entertaining the possibility of some of the wilder claims now since so much of what I heard would happen up to this point has indeed happened, but I await my own verification.

In the end, should you investigate this for yourself, you'll be the judge of whether this stuff is real and yours will be the most important opinion to you.