What did you dream about last night? Don't lie - science can tell! Researchers from Kyoto, Japan, have built a dream-reading machine that can pluck images straight out of your slumbering, dreaming brain:
As the fMRI monitored blood flow to different parts of the subjects’ brains, they drifted off to sleep; then, once the scientists noticed that they’d had entered stage 1, they woke them up and asked them to describe what they were previously seeing while dreaming. They repeated this process nearly 200 times for each of the participants.
Afterward, they recorded the 20 most common classes of items seen by each participant (“building,” “person” or “letter,” for example) and searched for photos on the Web that roughly matched the objects. They showed these images to the participants while they were awake, also in the MRI scanner, then compared the readings to the MRI readouts from when the people had seen the same objects in their dreams. This allowed them to isolate the particular brain activity patterns truly associated with seeing a given object from unrelated patterns that simply correlated with being asleep.
They fed all this data—the 20 most common types of objects that each participant had seen in their dreams, as represented by thousands of images from the Web, along with the participants’ brain activity (from the MRI readouts) that occurred as a result of seeing them—into a learning algorithm, capable of improving and refining its model based on the data. When they invited the three sleepers back into the MRI to test the newly refined algorithm, it generated videos like the one below, producing groups of related images (taken from thousands on the web) and selecting which of the 20 groups of items (the words at bottom) it thought were most likely the person was seeing, based on his or her MRI readings