Update to 89-year-old motor homunculus model shows brain's motor cortex isn't as neatly organized as previously thought

For almost a century, budding neuroscientists have been taught that the headband-like strip of brain tissue over our ears that controls our movements, called the motor cortex, contains an orderly map of our bodies.

Brain cells concerned with moving each body part—from the tips of our toes to the tips of our fingers—are all laid out in sequence, as well as a large zone dedicated to our fabulously expressive faces and speech muscles.

That's the textbook account, anyway. ...