STAR-NOSED MOLES EXEMPLIFY THESE PRINCIPLES OF FUNCTIONALORGANIZATION The star-nosed mole with which weopened this chapter provides a clear example of these organizationalprinciples. Figure 15.9a,b shows side views of the cerebralcortex of an African hedgehog (Atelerix albiventris) and a starnosedmole. The hedgehog brain (Figure 15.9a) shows a localizationof cerebral cortical function typical of small and relativelyunspecialized mammals, with large areas devoted to visual andauditory functions, a primary somatosensory area (S1), and twosmaller somatosensory areas (S2, PV) below it. The cerebral cortexof the star-nosed mole (Figure 15.9b) has impressive differencesin size of the cortical representations. Both brains demonstratelocalization of function (like Figure 15.7), with particular areasperforming particular functions, and both brains show somatotopicmaps, with particular areas of the body projecting to particularplaces in the brain (as shown in Figure 15.8). The sizedifferences in the brain representations of the star-nosed molereflect the unimportance of vision and the importance of somatosensoryfunctions, particularly of the “star,” which has threesomatosensory representations that together occupy more areathan that devoted to the rest of the body (Figure 15.9c). Finally,the star-nosed mole shows evidence of plasticity in developmentof the brain; a few moles develop with 12 rather than 11 rays inthe star, and developing sensory neurons from the “extra” rayinduce a corresponding extra cortical representation to whichthey indirectly project!