Researchers in Japan have found a way to "see" dreams using computers.
The researchers, based out of ATR Computational Neuroscience Laboratories in Kyoto, were able to train computers to recognize images that appeared in dreamers' minds during the early dreaming process.
In order to do this, the researchers placed three volunteers inside a magnetic resonance imaging machine that tracks blood flow to the brain, indicating neurons at work. By hooking the volunteers up to electroencephalograph machines, they recorded these neurons' electrical activity. When the volunteers fell asleep, the researchers woke them every six minutes to obtain a verbal description of what each volunteer was dreaming about. The computer then searched for links between brain activity and the images the dreamers described.
The result was that the computers were able to decode dreams with an average accuracy of 60 percent.
"It's very exciting work," said Dr. Brice Kuhl of NYU's Department of Psychology. "The authors used sophisticated neuroimaging techniques to 'read out' the contents of a participant's dreams based on patterns of activity in areas of visual cortex. These readouts were then compared to the participant's verbal descriptions of their dreams, confirming that the authors were impressively successful at decoding the contents of dreams."
"While I don't think the findings are necessarily surprising at a theoretical level, in that we had good reason to suspect that the images we dream about are related to activity in visual cortical areas (studies of memory and imagery have shown similar relationships), it represents a bit of a methodological breakthrough to be able to decode dreams in humans using noninvasive brain imaging techniques," Kuhl added.
Currently the computers can only detect basic objects that the dreamers visualize, such as "key" or "house." Researchers may not be able to use the technique to decode dreams that arise during REM sleep.
The study does, however, hold important implications for the study of dreams and brain function in general.
"Because not all of the information we dream about is readily remembered when we wake, this approach also offers the potential to 'see' what participants are dreaming about even when they will ultimately be unable to remember these dreams," Kuhl said. "Given our increasing appreciation for the relationship between sleep and memory, this approach also holds tremendous promise for relating brain activity during sleep to sleep-induced changes in memory."
The study was published Thursday April 4 in the journal Science.
