How The Human Brain Separates, Stores, And Retrieves Memories

Researchers have identified two types of cells in our brains that are involved in organizing discrete memories based on when they occurred. This finding improves our understanding of how the human brain forms memories and could have implications in memory disorders such as Alzheimer's disease.

The study was supported by the National Institutes of Health's Brain Research Through Advancing Innovative Neurotechnologies (BRAIN) Initiative and published in Nature Neuroscience. Researchers worked with 20 patients who were undergoing intracranial recording of brain activity to guide surgery for treatment of their drugresistant epilepsy. They looked at how the patients' brain activity was affected when shown film clips containing different types of cognitive boundaries transitions thought to trigger changes in how a memory is stored and that mark the beginning and end of memory files in the brain.

The first type, referred to as a soft boundary, is a video containing a scene that then cuts to another scene that continues the same story. For example, a baseball game showing a pitch is thrown and, when the batter hits the ball, the camera cuts to a shot of the fielder making a play. In contrast, a hard boundary is a cut to a completely different story imagine if the batted ball were immediately followed by a cut to a commercial.