Why do we kiss our lovers on the lips? We could show romantic passion by rubbing foreheads, locking elbows, or by turning back-to-back and bumping butts. We could even mash our ears together. Legend ...

Sense receptors distributed over the body surface are represented in corresponding sensory maps in somatosensory cortex (S1). Like in Penfield's "Homunculus" illustration, their size in S1 is dictated ...