The Nobel Foundation · Public domain

A physiologist who, with Herbert Gasser, identified that nerve fibers come in distinct varieties carrying signals at different speeds depending on their diameter — a finding that gave neuroscience its basic vocabulary for how the nervous system transmits information. Using an early oscilloscope to record electrical activity in nerves, they established the relationship between fiber size and impulse velocity, work recognized with the 1944 Nobel Prize in Physiology or Medicine.