This is the only place ive ever been able to find information about how science explains hallucinogens but i dont nessicarily like the website it comes from....

http://deoxy.org/psyguide.htm#5

"There is no question a certain degree of merit to this hypothesis. However, one could ask as well: are there perhaps latent functions in the brain that are turned on by hallucinogens? This point of view has not been well addressed by scientific research for the simple fact that, how can you look at something if you don't know it exists? If there are functions turned on by hallucinogenic drugs in the brain that do not normally operate in our usual states of consciousness, then scientists have nothing to compare these states to, and thus are affected by a blind spot. Still, though this question of turning on latent functions is not easily addressed in terms of scientific thinking, we shall see below that occult views provide us a basis to reasonably address this question.

In spite of any hypothesis scientists may provide as to the operation of hallucinogens in the nervous system, we must put this discussion in its proper perspective. Whatever scientists may profess to know about the activity of hallucinogenic drugs is colored strongly by the fact that the current scientific understanding of how the brain and nerve cells work is highly incomplete.

And this point leads us back to philosophy. Because, on one hand, scientists like to believe that the brain creates consciousness, but on the other hand, scientist have only a partial and incomplete understanding of how the brain works. This seems like putting the cart before the horse to me. It is possible that science will come to understand in very full detail how the operation of the brain leads to memory formation and other psychological phenomena. But the point is, they only have a partial understanding at this point. If you took a brain scientist (a neurologist, or neurochemist, or whatever) and sat them down and asked; "How does the brain create consciousness?" They'll either B.S. you with a bunch of details and never directly answer your question, or they will out right honestly admit that this question simply cannot be answered with current knowledge (if you can't dazzle 'em with brilliance, baffle 'em with bullshit!). So, the bottom line is, that science's contention that the brain creates consciousness is more belief and dogma than it is cold, hard, provable fact."