Aroma and pink memory

2007/04/20 Galarraga Aiestaran, Ana - Elhuyar Zientzia

• Biokimika
• Anatomia/Fisiologia

Scientists have known for a long time that odors influence memory.

The research has been published in the prestigious scientific journal Science and, for their interest to anyone, will surely be more interesting for students. Neurologists have conducted the experiment with medical students. Students were made to make a memory game on the computer, remembering the location of the cards that appeared on the screen.

During the exercise, the aroma of the rose was brought to the students with the mask they had for it. As the brain adapts very soon to the odors of the environment and stops perceiving immediately, the perfume came running to them.

Half an hour after the exercise the students went to sleep. In a specific phase of sleep, half of the students obtained the aroma of the rose to smell. The others slept without special odors. The next day they asked them where the cards were and those who had aromatic dreams remembered 97% of the locations. On the contrary, those who spent a night without a smell of pink drew 86% of the locations.

The difference is evident and with it they showed that an smell, in this case the rose, serves to reinforce the memory. But that wasn't enough, the researchers wanted to know the underlying mechanism.

Deep sleep

Some of the processes that take place during sleep are essential to preserve memories.

For neurologists, a part of the brain, the hippocampus, is like a notebook. Here are written the lived or learned of a day, until they “pass clean” or are kept in memory in the long term. These memories are lit during sleep and passed to the cerebral cortex.

The researchers knew that odors have a great influence on the hippocampus and suspected that during sleep they could help to strengthen memories, but not at any time: for example, in the REM phase of sleep, that is, in the time of dreams, odors have no effect on memory.

That's bad news for students: using the rose aroma to learn better at exam time is not easy. But, at least, they have announced when it is the right time to smell; it seems that the hippocampus works in a deep sleep phase and then you have to take advantage of it to give it steam. In this way, memories are kept firmly in the long-term memory.

Odors help to memorize what has been learned in the long term.

This is what the researchers did: the students slept with the electrodes placed in the head and, analyzing the waves, the researchers knew when there was a deep sleep. At that time, half of the smell received the same aroma as in exercise. They did not wake up by smell and the next day did not remember that at night the roses had been smelled. However, the location of the cards was perfectly remembered, 11% better than those that did not smell anything special.

It is clear that it is difficult to experience at home and also does not serve for any type of learning. The aroma of pink is useless, for example, to learn to play the piano or to ride a bike, since the hippocampus does not participate in the memory of the activities. However, German neurologists have taken an important step in the research on memory and learning.

Published in Deia.