Scientists read dreams
October 23, 2012
Human brain scan (PET) (credit: Jens Langner/Wikimedia Commons)
Scientists have learned how to discover what you are dreaming about while you sleep, Nature News reports.
Researchers led by Yukiyasu Kamitani of the ATR Computational Neuroscience Laboratories in Kyoto, Japan used functional neuroimaging to scan the brains of three people as they slept, simultaneously recording their brain waves using electroencephalography (EEG).
The researchers woke the participants whenever they detected the pattern of brain waves associated with sleep onset, asked them what they had just dreamed about, and then asked them to go back to sleep.
The researchers extracted key words from the participants’ verbal reports, and picked 20 categories that appeared most frequently in their dream reports.
Kamitani and his colleagues then selected photos representing each category, scanned the participants’ brains again while they viewed the images, and compared brain activity patterns with those recorded just before the participants were woken up.
The researchers analyzed activity in brain areas V1, V2 and V3, which are involved in the earliest stages of visual processing and encode basic features of visual scenes, such as contrast and the orientation of edges. They also looked at several other regions that are involved in higher order visual functions, such as object recognition.
In 2008, Kamitani and his colleagues reported that they could decode brain activity associated with the earliest stages of visual processing to reconstruct images shown to participants. Now, they have found that activity in the higher order brain regions could accurately predict the content of the participants’ dreams.
“We built a model to predict whether each category of content was present in the dreams,” says Kamitani. “By analysing the brain activity during the nine seconds before we woke the subjects, we could predict whether a man is in the dream or not, for instance, with an accuracy of 75–80%.”
The findings suggest that dreaming and visual perception share similar neural representations in the higher order visual areas of the brain.
“It also seems to suggest that our recall of dreams is based on short-term memory, because dream decoding was most accurate in the tens of seconds before waking,” he adds.
Kamitani and his colleagues are now trying to collect the same kind of data from the rapid eye movement (REM) stage of sleep, which is also associated with dreaming.
Comments (8)
by Scoot
Did anyone else notice that when you glance away from the brain scan and look back the outer blue area seems to shrink?
by Dr.Pratt
Impressive!
by waxdrip
Dreams are like movies, so will scientists be getting Emmy’s in science non-fictions someday, too?
by IONE
No, but dreamers will! Oscars, Emmy’s and so on…. and more good stuff like that!
by melajara
This is the central subject of a very prescient movie Wim Wenders “Until the End of the World”. Globalization, Internet pervasiveness, tablets, a more scenic way of life, avatars and brain reverse engineering, all mingled in a touching story. A true masterpiece with a grand moral lesson: don’t be so absorbed in deciphering your own fantasies as to lose touch with the external world, and don’t forget that our next collective goal is to move on, from the intricacies/fallacies inhabiting our skulls to outer space!
by melajara
I forgot an essential info tidbit, it was a 1991 movie and some of the tech envisioned will be available only circa 2017: AGI cartoon avatars acting as personalized search bots deployed over the net (remember, in 1991, it was still just Arpanet and newsgroups available over monochrome vt220 terminals), phenomenal vision!
by MarkOates
Ooh, yea. This is a good one.
So right now, their model gives an accuracy of 75–80% on a simple topic/keyword. Not bad. We’ll be up in the 95% before too long and the topics will only become more specific.
I think in 30 years or so we’ll see the human brain to be surprisingly disappointing in its capacity – impressionable, impulsive, dependent, slow, and generally limited in making good decisions.
by MrFriendly
They are getting really good at this. Crazy.