ABOVE: A computer rendering of electrode arrays implanted in the hand knob area of the brain
JAIMIE HENDERSON/STANFORD UNIVERSITY
In the 1930s, neurosurgeon Wilder Penfield and his colleagues put out a model for understanding how the brain controls movement that they termed the motor homunculus. The central idea was that different parts of a brain area called the precentral gyrus are charged with moving the hands, legs, face, and so on. While the idea was recognized as a simplification from the beginning, and has been further complicated by subsequent studies, it remains true in neuroscience that different areas of the gyrus specialize in controlling specific parts of the body.
One of those areas is the “hand knob,” which, as the name suggests, is a knobby region of the gyrus involved in hand and arm movements. It also has another, surprising function. A team based at Stanford University reports today (December 10) ...
