deep brain stimulation and run wires to certain parts of the brain to help her to feel a lack of craving, feeling satiatation. it showed some promise. but as a clinical psychologist, i think what are the circumstances besides the physiology that are going on that can be affected. >> larry: back to the basics, cara. why does the brain do dumb things? >> wow. >> that's a question. >> that's a difficult question. >> that's a good one. >> i think we have a lot of -- the brain, as dr. drew was saying, is messy. it's evolutionarily messy. being higher order and higher thinking, mammals, the executive function can get in the way of the more unstable brain processes. we have a lot of cognitive biases and fallacies that we have to face every day. and one example would be a fallacy that a lot of people getting back to overeating will