Udhay, these studies may be new, but this is by no means a "new" subject.
Roman "aristocrats" (or otherwise well-educated people) shifted from Greek to Latin depending on who they were talking to - and what they were talking about. And there have been many similar situations, in all sorts of cultures, through the centuries and millennia.
It is not necessarily "unconscious". In a conversation with someone who shares two or three languages with me, we often shift instinctively, but quite deliberately, to whatever language or jargon best suits what we are saying.
Even when I am thinking or "mentally talking to myself" thoughts take shape in whichever language suits the purpose (within the limits, of course, of what I know).
I believe that understanding more than one language is a mind-opener. Cheers, Giancarlo
