Brain Cells for Grandmother

For decades neuroscientists have debated how memories are stored. That debate continues today, with competing theories—one of which suggests that single neurons hold the recollection, say, of your grandmother or of a famous movie star. The alternative theory asserts that each memory is distributed across many millions of neurons. A number of recent experiments during brain surgeries provide evidence that relatively small sets of neurons in specific regions are involved with the encoding of memories. At the same time, these small groupings of cells may represent many instances of one thing; a visual image of Grandma's face or her entire body—even a front and side view or the voice of a Hollywood star such as Jennifer Aniston.