Sleep right after school

The best way for us to remember poems or math formulas is to try to sleep right after reading them.

Discovery News said that Bjorn Rasch and colleagues at the University of Basel, Switzerland recruited a number of volunteers to study the role of sleep in memory. They train volunteers to remember the position of cards in the grid line system. During the volunteer study, the team released a scent for them to smell. Many previous studies have shown that people often recall an event if they smell the fragrance associated with the event.

Scientists ask some volunteers to sleep, while others are awake when the training is over.

20 minutes after the volunteers slept, they and the awakened people exposed the scent again to activate the memory. The team waited another 20 minutes and woke up the sleepers. They asked both the sleeping group and the final group to do something else to disperse their thoughts.

Half an hour later, experts asked volunteers to recall the location of the cards during the training session.

The results show that, when there is no scent, all volunteers remember exactly 60% of the cards' position.

But when the scent was released, the correct memory rate of the final group was about 42%, only half of the 84% of the sleeping group.

'As expected of us, the procedure to re-activate memories when awakening made memory unstable. Conversely, if re-activating the memory during the period when people begin to sleep, the ability to remember will increase. The procedure also helps the brain increase its resistance to external effects during memory, 'the team concluded.

The team also used functional magnetic resonance imaging to monitor the brain activity of sleeping groups and consciousness groups. The results show that the activity of the human brain is completely different from the consciousness of the mind when both groups smell the fragrance. In the brain of consciousness, only the frontal area is active. In contrast, the outermost layer of the cortex and the hippocampus are activated in the sleeping human brain.

According to the team, releasing the scent when volunteers sleep helps their memories return to an unstable state, whereby it is strengthened or updated.