I haven’t seen anything official, but it strikes me as obvious that our brains would do weird things if you SEVER THE FREAKING LINKS THAT BIND THE TWO HALVES TOGETHER.
The brain is an organ designed for several things, among which is the ability to think. If you intentionally break it, it might start thinking in broken ways. That doesn’t mean we are “naturally” two different consciousnesses. At the resurrection, the brokenness will be restored and the person will be whole again.
