Brains facilitate survival and reproduction by making helpful links between sensory input and motor output. . . . Therefore, the basic design problem for a brain is to link each stimulus to the relevant response—that is, to get the important incoming information about the environment connected to the proper place(s) in the brain where relevant knowledge is stored and optimal responses are prescribed. . . . As the brain becomes larger and more com- plex, with more different sets of information stored in various places, the difficulty of this problem (of linking stimulus to optimal response) increases exponentially
#