Lucid Dreaming again. No, Co-Dreaming

I had an experience years ago when I was personally studying with a woman who was well-taught by a White Mountain Apache medicine woman.  At one point during my first year of study with her, while she was coaching me in dream work, I shared a dream I'd had the night before, with her in it.  She stopped me mid-sentence, and finished telling me about the dream.  We'd approached the dream subject from our own unique perspectives, had our individual experiences, but it was the 'same dream', essentially.  I've never forgotten how amazing that was.

Well, a few nights ago (years later, a totally different cirsumstance) it happened again.  As I was sharing a dream from the night before with my friend Marcia, and that she'd appeared in my dream, she suddenly got looked very pensive.  When I was finished, she told me of her own dream, and the unmistakable elements where we had shared the same dream.  Again, amazing.  It reminds me of when I was teaching some lucid dream workshops during the mid-1990's, and we'd end the class by saying, "See you in the dreamtime'.  I had one distinct experience then of sharing a dream with someone, where we both walked toward a blazing bonfire on the beach, conversed for awhile, and then went our separate ways.  Since it happened during the Friday night of a Friday and Saturday workshop, we were able to share the dream the next day.

Being a 'closet scientist', I wonder if there have been any scientific studies done on what the Australiam Aborigines call Dreamtime?  I wonder if, when people sleep together in close quarters, their brain waves come to be more in sync with one another?  Similar to women's menstrual cycles becoming in sync when they live together in a group?  And, because the brain wave of natural sleep is different than when someone is in hypnosis, what may the difference in the brain waves of one who is dreaming, and/or lucid dreaming, and/or co-dreaming?