Scientists use brain scans to decode people’s dreams
It is hoped the experiment will lead to a much deeper understanding of the dream world and have important implications for psychotherapy and sleep research.
Yukiyasu Kamitani and his colleges at the ATR Computational Neuroscience Laboratories in Kyoto used functional magnet resonance imaging (fMRI) to scan the brains of three people as they slept.
When the scientist detected sleep patterns in the brain they woke the participants and asked them to describe their experience. The process was repeated at least 200 times for each subject.
The descriptions were then put into 20 broad categories such as: cars, man, woman, books and tools. Awake, the subjects had their brains scanned once more, while looking at pictures that represented the categories.
The data was then analysed by a complex computer program, which quickly recognised the signatures of brain activity that represents the images from the categories.
Finally, the machine used its knowledge to decode the dreams of the volunteers as they slept in the MRI machine again. Remarkably the computer identified images in the dreams with 60% accuracy.
Dr Robert Stickgold, a neuroscientist and dream expert from Harvard Medical School in Boston, described the study as ''stunning in its detail and success. This is probably the first real demonstration of the brain basis of dream content.''
Dr. Allen R. Braun, who studies the neural basis of language at the National Institute of Health, said that it is an important first step but the methods of the Japanese team might not work during deep sleep, characterized by rapid eye movement (REM sleep).
However, Kamitani and his research team are now trying to repeat the experiment during REM sleep and said: “This is more challenging because we have to wait at least one hour before sleeping subjects reach that stage. I don’t have a pet theory about the function of dreams knowing more about their content ands how it relates to brain activity may help us understand them.”
