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Scents can very simply help to better retain newly learned information during sleep, as researchers at the Medical Center - University of Freiburg show / Online experiment describes how the learning effect is particularly high / Publication in Scientific

Effortless learning during sleep is everyone's dream. It has been known for several years that odors can increase learning successif they are presented during learning and later again during sleep. Researchers at the Medical Center - University of Freiburg and the Freiburg Institute for Frontier Areas of Psychology and Psychohygiene (IGPP) have now shown that memory performance increases particularly when the scent is used for at least three days and nights. However, it was also shown that although scent facilitates learning, it does not prevent later forgetting. The study was published on February 9, 2023 in the Nature Group's open access journal Scientific Reports .

"We were able to identify conditions under which the supportive effect of scents works particularly reliably in everyday life and can be used in a targeted manner," says study leader PD Dr. Jürgen Kornmeier, Director of the Freiburg IGPP and scientist at the Department of Psychiatry and Psychotherapy at the Medical Center - University of Freiburg.

Rose scent during learning, sleeping and the final vocabulary test

For the study, first author and biology master's student Jessica Knötzele conducted an online experiment with 183 adult test subjects. The subjects were sent sealed envelopes containing either rose-scented granules or just paper shreds, along with detailed instructions on when and where to place the closed envelopes while learning Japanese vocabulary, sleeping and or during the final vocabulary test.

The vocabulary test results of the groups with scent in all phases (learning, sleep and test) were compared with test results in which only paper shreds were in the envelopes instead of scent during one or more phases. This study was carried out by Knötzele as part of her Master's thesis.

"The test subjects showed significantly greater learning success when the scent was used during learning, sleeping and during the vocabulary test," says Knötzele. The difference in scent-supported learning success even increased over the three days. "However, it must be said that although the scent helps with learning, it cannot prevent subsequent forgetting," says Knötzele.

Findings are suitable for everyday use

"It was particularly impressive that the scent also works when it is present throughout the night," says Kornmeier. "This makes the findings suitable for everyday use." This finding was already evident in our first study and has now been confirmed once again. Previous studies had always assumed that the scent should only be present during a particularly sensitive sleep phase. However, as this sleep phase can only be determined by a complex measurement of brain activity using an electroencephalogram (EEG) in a sleep laboratory, the finding was not previously suitable for everyday use. "Our study shows that we can make learning easier during sleep. And it is remarkable that our nose can help," says Kornmeier.

Original title of the study: Presenting rose odor during learning, sleep and retrieval helps to improve memory consolidation - a real-life study

DOI: 10.1038/s41598-023-28676-z

Link to the study: www.nature.com/articles/s41598-023-28676-z

Contact:
PD Dr. Jürgen Kornmeier
Institute for Frontier Areas of Psychology and Psychohygiene (IGPP)

and

Department of Psychiatry and Psychotherapy
Medical Center - University of Freiburg
Phone: 0761 207-2121
juergen.kornmeier@uni-freiburg.de