How many systems does the mammalian brain actually have, and what is each one really doing? Neuroscientist Bjorn Merker challenges conventional anatomical boundaries and proposes that the brain's major subdivisions, neocortex, cerebellum, basal ganglia, and brainstem, each perform a distinct generic function, running in parallel all the time rather than switching on and off. Subscribe for more from the Convergent Science Network podcast series. Bjorn Merker joins Paul Verschure and Tony Prescott for a wide-ranging tutorial on brain systems architecture. He begins by questioning how we define a system at all, showing that textbook divisions like midbrain and diencephalon dissolve under embryological and molecular scrutiny. Instead, he argues that genuine systems should exhibit redundant internal structure reflecting a generic function , as the cry ...