New Study Identifies Individual Brain Cells in Process of Summoning a Memory
The New York Times ran an interesting article last week by Benedict Carey about a new study on the brain which may lead to a new line of research into Alzheimer's and dementia. In the study, which was just published in the journal of Science, scientists found that they can identify individual brain cells that are in the process of summoning a spontaneous memory.
The study involved placing tiny electrodes into the brains of 13 people who suffer from severe epilepsy. These electrodes allow doctors to identify the location of brain activity that result in epileptic seizures. In this case, the research subjects watched short film clips, during which researchers tracked brain activity. After a short period of time with some distractions, the researchers asked the subjects to think about the videos and to share what thoughts came to mind. The researchers found that the brain cells that were activated by the initial playing of the video became reactivated a few seconds before the person was conscious of the memory.
"The recordings, taken from the brains of epilepsy patients being prepared for surgery, demonstrate that these spontaneous memories reside in some of the same neurons that fired most furiously when the recalled event had been experienced," Carey wrote. "Researchers had long theorized as much but until now had only indirect evidence."
Why is this important? Carey explained, "This ability to richly reconstitute past experience often quickly deteriorates in people with Alzheimer's and other forms of dementia, and it is fundamental to so-called episodic memory - the catalog of vignettes that together form our remembered past." University of Pennsylvania professor Michael J. Kahana (who wasn't part of the study) is quoted in the article as saying, "The exciting thing about this (research) is that it gives us direct biological evidence of what before was almost entirely theoretical."