This news release is available in Japanese.
Long-held social biases can be reduced during sleep, a new report suggests. It adds further support to recent research that has shown that memories can be selectively reactivated and strengthened during slumber. Scientists have known that sleep boosts memory formation by resuscitating faint neuron activity shaped during earlier periods, when an individual was awake. This process can be experimentally stimulated by giving a sleeping individual cues related to an earlier period of learning. Now, Xiaoqing Hu and colleagues extend these findings to show that this method not only works for recently learned information but also to influence implicit attitudes learned during childhood. The researchers focused on prejudices of race and gender. In a series of exercises designed to counter typical racial and gender biases, participants were shown pictures of men and women of different races. They learned to associate races and genders with opposing features (female faces with science-related words, for example, and black men with "good" words). A distinctive sound was associated with each type of counter-bias. The participants then took a 90-minute nap during which one sound, by random assignment, was repeatedly played to cue and reactivate a newly learned association. Shortly after waking, and again one week later, the researchers found that implicit social biases were reduced preferentially for the counter-bias training reactivated during sleep (but not for counter-biases not reactivated). Given the implications of this research for societal change, Gordon Feld and Jan Born say in a related Perspective, the study should inspire research to solve remaining issues of targeted memory reactivation during sleep so that its mechanisms are fully understood.
Article #14: "Unlearning implicit social biases during sleep," by X. Hu; J.W. Antony; J.D. Creery; I.M. Vargas; G.V. Bodenhausen; K.A. Paller at Northwestern University in Evanston, IL; X. Hu at University of Texas at Austin in Austin, TX; J.W. Antony at Princeton University in Princeton, NJ.