From Stephen Pinker's "How the Mind Works"

" The computational theory of the mind is not the same thing as the despised 'computer metaphor.'  As many critics have pointed out, computers are serial, doing onet thing at at time; brains are parallel, doing millions of things at once.  Computers are fast; brains are slow.  Computer parts are reliable; brain parts are noisy. Computers have a limited number of connections; brains have trillions.  Computers are assembled according to a blueprint; brains must assemble themselves. ... Human thought and behavior, no matter how subtle and flexible, could be the product of a very complicated program, and that program may have been our endowment from natural selection.  The typical imperative from biology is not 'Thou shalt...,' but 'If...then...else.'"

                                         ~~~~~~~~~~~also~~~~~~~~~~~~