Evolution of cognitive function via redeployment of brain areas.

The creative reuse of existing neural components may have played a significant role in the evolutionary development of cognition. There are obvious evolutionary advantages to such redeployment, and the data presented here confirm three important empirical predictions of this account of the development of cognition: 1) A typical brain area will be used by many cognitive functions in diverse task categories, (2) evolutionarily older brain areas will be deployed in more cognitive functions, and (3) more recent cognitive functions will use more, and more widely scattered, brain areas. These findings have implications not just for our understanding of the evolutionary origins of cognitive function but also for the practice of both clinical and experimental neuroscience.