Well, I can’t imagine Avicenna introduced the term psychobiology – sounds a bit too modern for him!

I would assume that psychobiology is more about what can be phsyically demonstrated about psychological events, rather than just doing standard psychology experiments on ‘whole people’, so that pscyhobiology would really be a particular focus of neurobiology??

As for finding out more- try Googling! I found …
http://www.bps.org.uk/psybio/psybio_home.cfm

straight off. Wiki’s definition is sort of what I’ve assumed above, but a bit broader.

Have fun – it sounds like the sort of subject that will be prone to ‘babble’ plus ‘dead obvious’ but also some true kernels of insight as well. Tread cautiously! (but then, tread cautiously in any kind of science that is about human behaviours!!!!)(SO many of the prevailing paradigms are highly, highly subjective and culturally and historically dependent!)