Final answer:
Hermann von Helmholtz was the scientist famous for measuring the speed of nerve impulses in the brain, contributing to the field of neurophysiology.
Step-by-step explanation:
The individual known for measuring the speed at which impulses travel in the brain is Hermann von Helmholtz. Hermann von Helmholtz was a German physician and physicist who made significant contributions to various fields of science. In the context of neurophysiology, he is credited with measuring the speed of nerve impulses, providing early insight into the electrochemical processes that occur in the nervous system. His contributions to our understanding of the physiology of vision and hearing, among other sensory mechanisms, were foundational to the field of biophysics.