According to a new study published Thursday in Science, prejudices against race and gender can be reduced through sleep.

Xiaoqing Hu, lead author of the study and a postdoctoral researcher at the University of Texas at Austin, worked to diminish implicit biases, which includes unconscious feelings of racism and sexism.

He made 40 participants to go through a bias-diminishing exercise. The participants who included male and female college students were asked specifically to make face and word pairings that went against implicit biases.

During the exercise, the subjects were cued up by special sounds. For example, every time one of test subjects clicked an association that reversed bias, a particular tone sounded in the background. There was a different tone for making a pairing that fought implicit racial bias.

After their testing, the subjects were asked to take a 90-minute nap and the sounds were played back to them.

Dr. Paller and his colleagues found the participants who heard the sounds while sleeping showed a reduction in bias. The researchers were able to lower their biases up to a week.

Sleep specialist Jan Born of the University of Tuebingen, who wasn't involved in the new study, showed promising results and how extremely powerful memory formation can be during sleep. However, he said there was more work left to do before the findings could make their way out of the lab.

He added, "This study shows that targeted memory reactivation can be used to 'implant' new memories that counter very deeply rooted memories of implicit attitudes. This is an impressive, novel finding, although, as a sleep researcher working in the same field of sleep-dependent memory formation, I personally was not too surprised".