It sounds like some dystopian future where our behavior is altered whilst we sleep, but scientists have been able to show that levels of prejudice can actually be modified by influencing the way the brain learns during nap time.
A team from Northwestern University was able to show that unwanted attitudes, in this case gender and racial bias, can be persistently modified by training the brain during sleep. What’s more, these changes endured for up to a week after the experiment had ended. The researchers think that the ability to alter undesirable behavior could have potential for many situations, but that we need to consider the ethics of it first.
The study, published in Science, focused on the unconscious biases that many of us hold. These biases often impact the way we interact with others. To do this, the researchers used an ongoing online study called Project Implicit, which was created by Harvard scientists to track and test people’s implicit biases on a range of subjects, from race to sexuality to religion. What they’ve found is quite unnerving.
For example, Project Implicit data suggested that 80% of people have a bias against the elderly and that in general people have a preference for white faces over black. They also found that stereotypes that associate science with men more than women persist regardless of country, and surprisingly are highest in Scandinavia, which we often identify as having a more gender equal society.
Taking this one step further, using the Project Implicit online test, Northwestern researchers presented participants with pictures of faces paired with words that were opposite of widely held stereotypes. For example, they displayed pictures of women surrounded by words associated with math and science, and pictures of black individuals surrounded by pleasant words. Whilst they were doing this, the researchers also played distinctive sounds to the participants.
They then got the people to redo the online test, which showed that their biases had decreased. Next, they were asked to take a short 90 minute nap. During this phase, and unbeknownst to the participants, the researchers played the distinctive sounds back to them. After the kip, they found that the subject’s gender and racial bias scores had dropped by a further 56%, and that even a week later their bias scores were still down by 20% compared to their initial baseline.
“We call this Targeted Memory Reactivation, because the sounds played during sleep could produce relatively better memory for information cued during sleep compared to information not cued during sleep,” explains Ken Paller, lead author of the study.
The researchers believe this could have all sorts of applications outside stereotype bias, for example to help change habit-forming behaviors like smoking or unhealthy eating. However, other scientists warn that caution should be taken as people are in a vulnerable and suggestive state whilst sleeping. In a commentary on the research, two psychologists Gordon Feld and Jan Born advise: “Aldous Huxley's description of a dystopian “brave new world” where young children are conditioned to certain values during sleep reminds us that this research also needs to be guided by ethical considerations.”