How does Serotonergic (5-HT2A mediated) Psychedelia work?
Brenton, the linked pdf is called "Multiple receptors contribute to the behavioral effects of
indoleamine hallucinogens". It goes into detail on a a few basic behavioral responses.  I don't know what your background is so if you need help understanding parts point them out to me and I'll give it a go.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3110631/pdf/nihms267079.pdf

https://docs.google.com/file/d/0B0JUrCVOms3MdzdlYmh0SnBmOHc/edit (I'm hosting the pdf on my Google Drive if you aren't able to see the link hosted by the NIH).