Cortical comparisons

Abstract

Abstract Fossils tell us about the timing of cortical expansion but reveal almost nothing about the evolution of cortical maps, which requires comparative research on living species. Maps from many mammals would be ideal, but the field relies instead on data from a few, reasonably well-studied species. Tree shrews and galagos, because of their places on the Euarchontan evolutionary tree, are especially important for understanding cortical evolution in primates. It is also essential to dispel some misconceptions. For instance, neuroscientists sometimes treat broad regions of cortex, such as the prefrontal cortex or the posterior parietal cortex, as a single thing. Consequently, small and relatively simple cortical regions in rodents are wrongly equated with large, complex suites of areas in primates. Other discredited ideas include replica-in-miniature-, amalgam-, triune-brain-, and dual-origin theories.