Researchers from MIT have determined that memories are stored in specific brain cells. This was found when triggering small clusters of neurons in the brain and asking test subjects to recall certain specific memories. They found that when these neurons were removed, subjects would be unable to recall said memories altogether. This is proof that memories are in fact physical rather than conceptual. They are now looking into how memories are encoded.
The Spotless Mind
The tests were conducted using optogenetics, a method that genetically manipulates cells by making them sensitive to light. By breeding genetically engineered mice with optogenetic neurons, scientists were able to trigger the modified cells using lasers instead of electrodes, which cannot be attached to neurons. Co-author Steve Ramirez says that “the more we know about the moving pieces that make up our brains, the better equipped we are to figure out what happens when brain pieces break down.”