The brain is the most complex organ in the human body, but for years, available technology greatly limited scientists interpretation technology greatly limited scientist interpretation of how the billions or neutrons act in concert to create complex behaviors. Recent advances in neuronal recording technology, however, along with the invention of the pentium processor based computer capable of digitizing the data at an a much higher rate than ever before, have enabled brain research to progress at an increasingly rapid pace.

By implanting up to fifty elecrodes, which recorded activity from neutrons in three different brain regions simultaneously, the study was one of the first to compare entie populations of neutrons from multiple areas of the primate brain. As the monkeys performed different visual search tasks, the researches compared the activity of neurons in the parietal and frontal corties. They found that in search trials where the item the monkeys were looking for was extremely obvious so called bottom up processing the parietal cortex reacted first, followed by the frontal cortex. In contrast, when the monkey  must actively search for the target so called top down processing the signal flowed in the opposite direction.