Researchers from Ruhr-Universität Bochum and the University of Bonn have investigated which activity patterns occur in the brain when people remember or forget things. They were interested in how the brain replays and stores during sleep what it had learned before. The team recorded the brain activity of epilepsy patients who had electrodes implanted into their brain for the purpose of surgical planning. One result: During sleep, the brain even reactivates memory traces that it can no longer remember later on.
Dr. Hui Zhang and Professor Nikolai Axmacher from the Department of Neuropsychology in Bochum describe the results together with Associate Professor Dr. Juergen Fell from the Department of Epileptology in Bonn in the journal Nature Communications, published on 5 October 2018.
Learning task before afternoon nap
For the experiment, the test participants were given a series of pictures to memorise. They then took an afternoon nap. When looking at a picture, the activity in the brain shows a pattern that differs somewhat from picture to picture. The researchers were able to measure these differences in high-frequency activity fluctuations – called gamma band activity. They analysed brain activity not only during the learning task, but also during sleep. They then tested which images the participants could remember after sleep and which they could not.
Read more at Ruhr-University Bochum
Image: Hui Zhang and Nikolai Axmacher (Credit: RUB, Kramer)