What is memory? This is a question that can only be truly answered on the biological and psychological level. Biologists have attempted to explain memory as the faculty of the mind by which information is encoded, stored, and retrieved. This process of doing so is connected to limbic systems. It is also the basis to ‘intelligence’; without memory it is impossible to recall past events, learn or develop language, or form relationships. Here biological explanations of memory cross-link to the psychological: What are bad memories? False memories? Why do we recall somethings and not others?
These are complex issues and it seems that even the established biological process by which memories are formed is not so clear cut. At a basic level, the brain is made up of two main types of cells: neurons and glia. Neurons form the biological basis of mental processes such as memory; glia have a supporting role (delivering nutrients, recycling molecules, providing electrical insulation, etc.). This is a simplified process, given there is a distinct difference between short-term memory; long-term memory; and memory-loss. However, it serves as a backdrop for the new Japanese-U.S. research.
The scientists have discovered that the brain “doubles up” by simultaneously making two memories of events. One of these memories is for the here-and-now whereas the other for a lifetime. This runs against the prevailing theory that all memories start as a short-term memory and are then slowly converted into a long-term one, with the hippocampus region of the brain being the place for short-term memory storage and the cortex functioning as the home to long-term memories.
Using mice, the researchers used new techniques to watch specific memories form as a cluster of connected brain cells in reaction to a shock. The BBC reports that the scientists next used light beamed into the brain to control the activity of individual neurons. By doing so they were able to switch memories on or off. Through this, the researchers showed that memories were formed simultaneously in the hippocampus and the cortex.
The findings came as a surprise to the researchers. One of the project heads, Professor Susumu Tonegawa is quoted by Futurism as saying: “This is contrary to the popular hypothesis that has been held for decades. This is a significant advance compared to previous knowledge, it’s a big shift.”
The study results are published in the journal Science, under the title “Engrams and circuits crucial for systems consolidation of a memory.”
