As we look at every person or object, specific neurons in our brain fire for each separate memory we store. It's hard to believe that billions of different neurons fire for each individual memory, but a professor at California Institute of Technology found ways to prove the theory of concept neurons. The professor, Christof Koch, argues that everyone has these so called "concept neurons", which help us remember things, especially people. He used new advances in brain surgery to perform his experiment. While two different subjects were under open brain surgery and still conscious, Koch placed images of actresses in front of the subjects. For one subject, a single neuron fired when images of Jennifer Aniston were placed in front of their face, but didn't fire when images of Jennifer and Brad Pitt were shown to them. The other subject's single neuron fired when pictures of Halle Berry were flashed in front of them. Another interesting aspect of the second subject was that the neuron also fired when the word "Halle Berry" was shown to them. This experiment at least brings into light how our brain stores specific memories with single neurons. I think with improved methods of research, we will continue to find out how our brain stores memories and recalls them. You can read more about concept neurons here.