An open yearbookWhat mechanisms facilitate the creation of long-term memory? Repetition of brain patterns and rest are important for the memory consolidation process, according to research done at the German Center for Neurodegenerative Diseases (DZNE), in collaboration with the University of Bonn, Germany. The research, led by Nikolai Axmacher, a scientist in the Department of Epileptology with both organizations, used brain imaging to track brain activity during a series of memory tasks. The results indicate that the more frequently that the brain’s memory patterns are activated, the stronger the memory.

The study was based on two theories about memory. The first theory suggests that memories are stored in the brain gradually. That is, new data is temporarily stored and then “consolidated” into the long-term memory. Other studies have suggested that “reactivation,” when the brain “replays” a memory also plays a role.

For the research, they recruited ten healthy participants with an average age of 24 years. The participants’ brain activity was recorded for several hours as they went through two tasks and took breaks. In the first activity, the participants viewed a series of pictures. Each picture had a white square located somewhere on it. The participants were asked to memorize the square’s location. Later on, they did a second task in which they looked at the same pictures, but without the squares, and had to identify where the squares had been located.

The researchers used a pattern-recognition program to process the data. It compared the participants’ brain patterns in the first and second tasks to identify neuronal patterns used during initial memory encoding and in later memory access.

The findings indicate that memory performance is related to the replay of activity patterns in the brain. Axmacher explained the results, stating, “The more frequently a pattern had reappeared, the more accurate test participants could label the corresponding image. These results support our assumption that neural patterns can spontaneously reappear and that they promote the formation of long-lasting memory contents.”

The results also suggest that rest periods play an important role in the consolidation of memory.

This research is published in The Journal of Neuroscience.

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