The twilight (朦胧的) time between full wakefulness and being sound asleep may be packed with creative potential. Rumor has it that Thomas Edison, the famous inventor, used to prefer such moments between wakefulness and sleep. Supposedly, he used to fall asleep in a chair holding two steel balls. As he fell asleep, the balls fell into metal pans. The resulting sound woke him. Then, he could write down his inventive ideas before he fell into a deep sleep and forgot them.
Researchers tested Edison's method of developing creativity with 103 healthy people. Volunteers came to the lab to solve a tricky number problem. After doing the task 60 times, they earned a 20-minute break in a quiet, dark room. They relaxed in chairs, each holding a light drinking bottle, something like the steel balls that Edison used. Participants were told to close their eyes and rest or sleep if they desired. Meanwhile, machines monitored their brain waves. About half of the participants stayed awake. Twenty-four fell asleep and stayed in the shallow short stage of sleep called N1. Fourteen others progressed to N2, a deeper stage of sleep.
After their rest, participants returned to their number problem. The researchers saw a clear difference between the groups. People with a shallow early sleep were 2.7 times as likely to spot the hidden trick as people who stayed awake. Shallow sleepers were 5.8 times as likely to spot the trick as people who reached the deeper N2 stage.
Such differences in such experiments are rare, says Delphine Oudiette, a cognitive neuroscientist. "The results raise an interesting possibility. It may help people to learn to reach that twilight stage of sleep on demand. It seems Edison was onto something about the creative powers of nodding off. But don't put too much faith in his habits. He also is said to have considered sleep ‘a criminal waste of time'."
