Actually, Buddhist practitioners have been “researching” this for hundreds of years. It can even be seen as a positive, a sign that you’re letting go of old concepts of self and other, opening up to the potential for greater connection with the world around you. But it can be dangerous territory for some.
My own experience has been that this happens rarely but it can be most unnerving when it does. It usually comes on during a retreat as a result of all the extra time spent in meditation. It’s like the proverbial rug being pulled out from under your feet. There’s a profundity to the experience that’s undeniable but you can be left feeling somewhat shaken. I’ve often had to retreat into the comfort of the known for a while afterwards to recover.
What you need at these times is a guide or at least someone who understands roughly what you’re going through because they’ve been there too. And it does concern me that, with the way mindfulness is mainly delivered as a discrete 8 week course, there might not be the continuity of guidance that there is in the more traditional Buddhist settings where Sangha (community) is seen as essential. Though, I think this is starting to develop with more ongoing mindfulness drop in classes and one day or weekend retreats with access to the counsel of an experienced, genuine mindfulness teacher.
For me, as an aspiring mindfulness teacher, it’s something to think about carefully. So my humble advice to someone starting out with mindfulness – keep an open mind, don’t be alarmed if difficult feelings rear up, but do talk to a trustworthy mindfulness teacher about it and see if you can find a group of other mindfulness practitioners to link into and so find your own mindfulness sangha. I myself couldn’t survive without it.