Dreams have always been an interesting topic for scientists, especially those interested in how the mind works. Freud famously called dreams the royal road to the unconscious, and thought the contents of dreams could shed light on dreamers’ hidden thoughts and feelings. His book Interpretation of Dreams (read it here) spelled out how to interpret the presence of certain objects or actions in a dream, for instance, descending a ladder might represent sex or having your teeth pulled might represent, well, sex. Modern researchers have benefitted from the development of tools like EEG and fMRI to investigate what is going on in our brains while we’re dreaming, but the truth is we still don’t have a very good explanation for why we dream or what our dreams mean.
I had a good friend in high school who could vividly remember his dreams. Every morning in homeroom, he’d recount the details from his previous night’s sleep. A lot of the time, his dreams involved animals doing people activities, like penguins playing hockey or dogs working at a bank (maybe he watched Animal Planet before going to bed, I don’t know); sometimes the dreams were really mundane, like going to football practice or taking a test; and other times they were just bizarre, like the time he married his car. Maybe he embellished some of the stranger stories, but he had me totally convinced, and it’s not like there was any way that I could call him out or disprove him: “You say you had a dream where you met Han Solo and he gave you some pistachio ice cream? Liar! I was there too, and he gave the ice cream to the talking fish!”
As it turns out, a team of scientists in Japan just published a study in the journal Science claiming that they can use fMRI to see what people are actually dreaming about. Participants in the study literally got to sleep on the job: they were told to doze off while their brains were scanned. It wasn’t a good sleep, though, as the scientists woke them up every few minutes to ask what they’d been dreaming about. The researchers then systematically analyzed the participants’ dream reports, and noted the different objects that the participants described from their dreams. Later, the participants took part in another brain scan, but this time, they were awake and looking at pictures of the objects that they had previously described dreaming about.
The scientists then taught a clever computer program to use the participants’ brain activity patterns while looking at objects to predict their brain activity patterns while they were dreaming. 60% of the time, the program made an accurate prediction, which is significantly greater than chance - if I could pick football games as well as this program can predict dreams, I would be a very wealthy man (if, you know, betting on sports was legal and I had any disposable income available for gambling). So basically, if the scientists on this study knew what my brain was doing when I looked at pictures of dogs, they could monitor my brain while I slept and see when I was dreaming about dogs. Amazing? Or creepy?
Before you get too excited or concerned about this, though, take a deep breath: this isn’t like something from the movie Minority Report. Nobody is going to be reading your mind without your consent or projecting your thoughts on giant screens anytime soon. The dream-decoding program can only work after extensive training with brain images, and it can’t use data from one person to predict the dreams of someone else. And, though 60% accuracy is pretty good in statistical terms, in the real world, it isn’t nearly good enough to put much trust - from a legal sense at least - in the program’s predictions. Still, this is another important step toward understanding our dreams, and I’m certain there will be more in the near future as we develop new ways to study the brain.