Contrary to popular belief that the mind rests while we are sleeping, new research suggests that the brain is highly active when our eyes are closed – and can even classify words.
In the journal Current Biology, researchers from Cambridge and Paris have published a study which compared the brain’s behaviour in participants when they were awake and asleep.
When awake, the participants were asked to complete a word test, during which their brain activity was recorded via an electroencephalogram (EEG).
For the test, they were required to classify spoken words as either objects or animals by pressing a button in their left or right hand.
Next the participants had to lie in a darkened room with their eyes closed while continuing the word classification task in their head.
After they had drifted off to sleep – and were completely unaware and motionless – scientists tested the participants with a new set of words. This was to ensure the brain had to figure out the meaning of…