These days we have some theory about this. See Stuart Hameroff MD, a Professor of Anesthesiology and Psychology, and Director of the Center for Consciousness Studies at the University of Arizona.
To sum it up from my limited understanding: This disturbs the quantum coherance in the microtubelies in all cells (But mostly nurons) which is needed for consciousness to "limit" itself to a identity.
To sum it up from my limited understanding: This disturbs the quantum coherance in the microtubelies in all cells (But mostly nurons) which is needed for consciousness to "limit" itself to a identity.