Scientists from California have figured out a way to use brain activity measurements to reconstruct natural movies seen by an observer.
A team of neuroscientists at the University of California, Berkeley, have successfully reconstructed YouTube videos from brain activities of viewers who have just viewed them. The scientists believe that the feat could pave the way for reconstructing our dreams on a computer screen.
The team of researcher used functional Magnetic Resonance Imaging (fMRI) and computational models to decode and reconstruct visual experiences in the minds of test subjects.
Some of the members of the research team acted as subjects of the research and watched YouTube videos staying still inside an fMRI machine for hours at a time. They watched two sets of movie trailers while the blood flow in their visual cortex was measured by the machine.
Scientists then used the data to develop computer models of the reactions that could predict the pattern of brain activity that would be elicited by any arbitrary movies that were not in the initial set used to build the model.
After that, scientists used fMRI to measure brain activity elicited by a second set of movies that were completely distinct from the first set. Then, in order to reconstruct the movies in the second set of movies, they used the computational models to process the elicited brain activity. They found that patterns of brain activity matched certain features of the videos such as colors, shapes and movements.
The study published in Current Biology said that all the reconstructions were obtained using only each subject's brain activity and a library of 18 million seconds of random YouTube video that did not include the movies used as stimuli. The study was led by Jack Gallant, a UC Berkeley neuroscientist.
We built a model...that describes how shape and motion information in the movie is mapped into brain activity, said Shinji Nishimoto, lead author of the study. We need to know how the brain works in naturalistic conditions. For that, we need to first understand how the brain works while we are watching movies.
According to Gallant and his team of researchers, the discovery is an important step in the development of brain-reading technologies that could someday be useful to society. They believe that there is the possibility of decoding dreams and imaginations in the future with some sort of a brain-machine interface.
Watch the video:
The left clip is a segment of the movie that the subject viewed while in the magnet. The right clip shows the reconstruction of this movie from brain activity measured using fMRI.