Invasive
From Neural Wiki
Researchers can use electrodes to probe the activity of the brain in vivo (Latin term meaning while the brain is still inside the organism in question those non-biologists). Some rather amazing discoveries and experiments have been performed in this manner. Recently, using electrodes implanted in the brains of epileptic patients, scientists showed that certain neurons will respond to specific faces, such as Jennifer Aniston's [1].
[edit] Monkey work
As close evolutionary ancestors of humans, monkeys (and apes) are very good models for experiments designed to give clues about the human brain.
Dr. Nicolelis of the Duke University Medical Center has done remarkable work with monkeys, whereby electrodes implanted in the brain of a monkey could be used by an immobilized monkey to move a robotic arm. [2]
