Scientists report that a single neuron in your brain responds when you see a specific person. The controversial notion is sometimes jokingly called the "grandmother cell," meaning that your brain has one cell that recognizes your grandmother. Cal Tech computational neuroscientist Rodrigo Quian Quiroga and his colleagues suggest that this may not be too far from the truth. In a series of recent experiments, they showed subjects a series of snapshots of animals, buildings, objects, and celebrities. The subjects were epileptics who had already been implanted with sensors to monitor brain-cell activity. From News@Nature.com:
Various pictures of Jennifer Aniston elicited a response in a single neuron inside the medial temporal lobe of another patient. Interestingly, images of her with her former husband Brad Pitt did not sway this cell, the authors of the paper report…
Quian Quiroga also found that a lone neuron in one subject responded selectively to various pictures of the actress Halle Berry – as well as drawings of her and her name written down. Other cells were found to respond to images of characters in The Simpsons or members of The Beatles.
The team thinks that these brain cells probably respond to a range of different items, but that this limited study didn't include all the various pictures that might make a particular cell light up.