I thought the author did a really good job of explaining how hallucinogens affect the brain biologically. However, I was left wanting to know more about the psychological effects of the drugs. Perhaps the most interesting comment of the paper had to do with the report that users' personalities can change. Personality is one of the qualities that is an integral part of my definition of consciousness. To be conscious is to be aware of self and others and the distinctions between the two.
Personality is that psychological distinction.
It seems like such a permanant thing and yet for anyone who has worked with brain damaged individuals, it can change drastically after the injury. Personality also feels like a really personal thing. We like to think that our personality is our own, sort of a psychological fingerprint. The subject of altered consciousness is really fascinating. It is so strange to me that you can change things as basic as who you are and how you perceive the world just by popping a pill.