A new study suggests our brains do way more when we snooze than was once thought. We can even identify and categorize words while we’re sleeping.
Researchers used an electroencephalogram (EEG) to record the brain activity of 18 men and women as they completed a word classification task. The task involved listening to spoken words and then pressing a button using either the right or left hand to classify each word as being an animal (right hand) or an object (left hand).
The researchers placed each person in a dark room to complete the word classification tasks as they nodded off, and after they had fallen asleep — and the researchers recorded each person’s brain activity again.
The study found that people eerily could classify the words accurately while asleep. The same brain activity that triggered the left or right hand to push buttons when a person was awake occurred when the person was asleep too, even though the hand wouldn’t physically move during sleep.
“We show that the sleeping brain can be far more ‘active’ in sleep than one would think,” study co-author Sid Kouider, a cognitive neuroscientist at the Ecole Normale Supérieure in Paris, said in a written statement. “Far from falling [into] a limbo when we fall asleep, parts of our brain can routinely process what is going on in our surroundings and apply a relevant scheme of response.”
Future studies may determine whether we could take advantage of our brain’s processing ability and complete automated tasks while we’re asleep.
The study was published online in the journal Current Biology on September 11, 2014.