“When the neocortex wants to do something, it sends a signal to the old brain, in a sense asking the old brain to do its bidding. For example, breathing is a function of the brain stem, requiring no thought or input from the neocortex. The neocortex can temporarily control breathing, as when you consciously decide to hold your breath. But if the brain stem detects that your body needs more oxygen, it will ignore the neocortex and take back control. Similarly, the neocortex might think, 'Don't eat this piece of cake. It isn't healthy.'' But if older and more primitive parts of the brain say, 'Looks good, smells good, eat it,' the cake can be hard to resist.” NeuroscienceJeff HawkinsA Thousand BrainsNeocortexBrain Stem Book:A Thousand Brains: A New Theory of Intelligence Source: A Thousand Brains: A New Theory of Intelligence