These two podcasts, http://twit.tv/fib52, http://twit.tv/fib55, of an interview with Rahul Sarpeshkar discussing Ultra Power Bioelectronics provide a good summary of current knowledge on how the brain works. There is a decent understanding of how many areas computationally function. The biggest surprises were that the brain is a hybrid digtal/analog computer and something similar jpeg compression is in operation in the brains visual system