Israeli scientists have found the strongest evidence yet that people can learn new information while they are sleeping, rather than simply strengthening memories already made.
Anat Arzi from the Weizmann Institute of Science in Rehovot, Israel played tones to sleeping volunteers before wafting smells of deodorant, shampoo, rotten fish, or dead animals past their noses. The smells triggered a sniffing reflex and the pleasant ones drew stronger sniffs. Then, when Arzi played the tones alone, the volunteers still sniffed, and more strongly to tones that had been paired with nice odors.
This conditioned response lasted through the night and into the next morning when the volunteers woke up. Although they still sniffed when they heard the tones, none of them were aware of what they had learned.
“This work is transformative in that it shows that humans can acquire information not only without awareness but also in a non-conscious state,” ...