Scientists used to think that sleep boosts the brain by helping us consolidate memories and learn new things. But now a provocative latest study has shown that it may even prove helpful for us in reversing deeply rooted stereotypes against women and African-Americans.

This finding has significant implications in the case of the state of race relations in America, and the gender gap in math and science.

Study lead author Dr. Xiaoqing Hu, a postdoctoral researcher at the University of Texas at Austin told The Guardian, "These biases are well-learned. They can operate efficiently even when we have the good intention to avoid such biases. Moreover, we are often not aware of their influences on our behavior".

Researchers measured the disturbing biases. For the study, they recruited 40 white men and women of the age group 18- 30 years old and told them to complete a task known as the Implicit Association Test (IAT). This test measured their baseline gender and racial biases.

After this, the participants completed two 'counter-stereotype trainings'. These trainings involved looking at different faces-black and white, and male and female -paired with words on a computer screen.

Researchers asked the participants to press a button labeled 'correct' when female faces appeared next to science and math words, and when black faces were paired with positive words, including cheer, smile, or honor.

Two specific sounds were played when the participants identified these pairings quickly and accurately. One sound was for the 'women-science' pairing, and the other one for the 'black-good' pairing.

Participants took a 90-minute-long nap after the training. When they fell into a deep sleep, researchers played one of the two sounds repeatedly. After waking up, the participants again took the IAT.