Memory formation: Learn better with the scent of roses

Those who learn with the scent of roses and breathe in the scent at night can learn better. A Freiburg research team observed this in an experiment. But why does the brain learn better together with scents?

What gets into the human long-term memory and what doesn’t? The brain has to constantly filter, make decisions. “This is where the scent comes into play,” says neurobiologist Jürgen Kornmeier from the Freiburg Institute for Border Areas of Psychology and Mental Health.

In the in the specialist magazine “Nature” In the study published, the study participants had to learn Japanese vocabulary. Those who learned together with the scent of roses and inhaled the scent at night did better in the later vocabulary test. All 165 test subjects received scented envelopes and learned a total of 40 words over three days. Only half of the study participants actually got the scent of roses. The other half only had scraps of paper in the envelope. The comparison between the two groups shows that those who had learned with the scent of roses were able to remember 8.5 percent more vocabulary on the vocabulary test.

Why the brain learns better with scents

“When we learn something, it’s always about the context,” says Kornmeier dem SWR. Fragrances can play a role in this. The vocabulary is linked to the smell when learning. This should enable the brain to store what it has learned better and retrieve it during the test. That’s why the study participants were also allowed to smell the scent of roses in the subsequent vocabulary test. In this way, the brain should be able to retrieve the information associated with the scent, in this case the vocabulary, more quickly.

Brain scans and earlier experiments with rats have shown that scents activate the brain particularly strongly. Above all, the hippocampus in the brain, the mediator between short and long-term memory, is activated by scents. According to the theory, information recorded at the same time then reaches deeper into the long-term memory.

Scent while sleeping improves memory

What the brain stores exactly is also decided during sleep. Previous experiments in the sleep laboratory have shown that during the deep sleep phase the brain rearranges at least part of what it has learned at night and decides which information goes into long-term memory. With the scent, the learning content of the day should be reactivated when the brain recapitulates what has been experienced and learned. “Then the probability increases that the learning content will be taken along in the consolidation process,” says Kornmeier.

Saving takes place especially in the deep sleep phase. If the brain has already linked information with the same scent during the day, the scent alone at night can help to store it in the long-term memory, according to the thesis. According to this, the same nerve cells are activated that have already fired in the waking state during learning.

Everyday fragrance effect

So far, previous studies have only observed the scent effect in the sleep laboratory. The fragrance was only presented during the deep sleep phase – out of concern that the fragrance could disturb the dream phases. “But we can present the scent all night and it still works,” says neurobiologist Kornmeier. This is the first time the scent effect has been observed in this form, not only in the laboratory but at home.

This makes the application more suitable for everyday use. Because in the Freiburg field study, the test subjects learned at home, not in an artificial setting, as is often the case with such tests, i.e. in the rooms of the research team.

Scent helps to achieve maximum learning

One thing is clear: the scent can only support. Nobody can do without the actual learning. But the scent does help when it comes to efficiency: it is particularly effective when there is little time to study, Kornmeier suspects: “Then it may be that the scent acts as a kind of booster.” Scents could help to reach one’s own learning maximum faster.

However, the use of a scent probably does not protect against forgetting. The scent effect could only be clearly observed in the first vocabulary test one day directly after the learning phase. A week or even a month later, the effect weakened significantly. The test results of the fragrance group were no longer significantly better than those of the others.

It’s probably not just the scent of roses that helps

Why actually rose scent? Most studies have examined possible learning effects with rose scent. “But that’s just a coincidence and is due to the original study,” says Kornmeier. The first study on the subject had experimented with the scent of roses. In order to be able to better compare our own results with this first study, the follow-up studies also used the scent of roses. “But I am firmly convinced that other scents also work. But of course this has to be shown in future studies.”

The smell of lavender, oranges or many other smells could help with learning, at least in the short term. However, the research teams are still only beginning to understand how the brain stores information in memory and processes it at night. One thing is clear: what smells good could at least help with the next vocabulary test or the next exam.