When we sleep, the brain makes an effort to enhance in our memory everything we have learned during the day. Furthermore, recent research has shown that if a specific learning task is associated with a smell or sound, and it is reproduced during sleep hours, what has been learned is consolidated more strongly in our minds .
According to the results of a Northwestern University study published in Science , this can also occur with values and attitudes learned during childhood. For their experiment, the researchers focused on racial and gender biases. In essence, it was a kind of training in which the participants observed images of men and women of different races, and learned to associate them with characteristics contrary to social prejudices. In addition, a distinctive sound was paired with each “counter” exercise.
At the end of the test, the participants took a 90-minute nap. Meanwhile, they repeatedly heard the sound used during training and a different one repeatedly. The surprise for the scientists was that these people noticed, shortly after waking up, how their racial and gender prejudices had diminished considerably, a sensation that they had in mind a week later. The scientists were clear about why: auditory stimulation during sleep had made possible the reactivation of counter-bias learning .
For the study’s lead author, Hu Xiaoqing, “it is somewhat surprising that sleep-based intervention can have an impact that was still evident a week later.” The common expectation, he explains, is that a brief, one-time intervention is not strong enough to have a lasting influence. “But our results show how learning, even this type of learning, depends on sleep “, he adds.
Although it seems somewhat surreal, this and other recent investigations were already carried out in 1932 by the writer Aldous Huxley , when he embodied in his novel Brave New World the idea of “training” children during their sleep, so that later they would feel proud of their values and the caste to which they belonged.
