Until the 1960s, scientists could study the brain’s electrical activity, but connecting a single neuron to a deliberate movement remained difficult. Edward Evarts changed this using implanted microelectrodes.
Evarts recorded individual neurons in the motor cortex of awake monkeys as they pulled a lever. He discovered that some neurons changed their firing with the timing and force of movement.
For the first time, researchers could listen to a single brain cell while an animal acted, linking neural activity directly to behaviour. The experiments involved invasive surgery, restraint, and trained primates—methods that also raise enduring ethical questions about the use of animals in neuroscience.
Last Updated on October 6, 2026 | Published: September 1, 2026