At the turn of the 20th century, British physiologists Charles Scott Sherrington and Albert Sidney Frankau Leyton started poking around in the brains of anesthetized great apes in their lab at the University of Liverpool to see what would happen. While their work would never secure the necessary permits in any laboratory today, the data they generated is in every modern neurobiology textbook, albeit in simplified form.
The researchers examined the brains of 22 chimpanzees, three orangutans, three gorillas, and a handful of other animals under deep anesthesia induced by chloroform and ether. Applying mild electrical stimulation to the cortex, they revealed that the control of certain body parts was localized to particular brain regions—a hotly debated topic at the time.
“There had been a lot of arguments about whether functions are localized,” says Roger Lemon, a neurophysiologist at University College London. While cortical stimulation had been shown to elicit ...