It was thought that the brain processed stimuli the way large companies process orders. Neurons at the bottom of a chain of command bring in data and pass it up the line. The higher level neurons take the raw data and either match it up appropriate responses, or if more work is necessary, add a little more data and pass it higher. The brain responded to external sources of data. A new study indicates that the brain actually processes stimuli the way large companies implement policies: from the top down. High level brain cells form an expectation of certain data, and hand it down to the lower neurons.