Dreams are among our most personal experiences. They take place in such a deeply recessed part of our brains that we can barely remember them ourselves, let alone convey to others what we imagined at night.
But a new study out of Japan may portend a future in which dreaming is more transparent. The study, which was reported in Science Express on April 4, used fMRI technology to analyze brain activity and predict with surprising accuracy the types of visual images that three research subjects experienced during their dreams.
The researchers used an innovative method make to these predictions. First, they monitored neural activity in the visual cortex during the first stages of sleeping. Then, they roused their study subjects and asked them to retell their dreams. Later, they monitored their research subjects’ brain activity as they looked at a series of images. They found, consistent with previous fMRI research, that whether subjects were looking at a picture of a tree or dreaming about a tree, the same part of their brains tended to light up.
This concurrence allowed the research team to compare waking brain activity and sleeping brain activity and predict the images that their subjects had seen in their dreams. Overall, they were able to predict visual dream contents with 60 percent accuracy. And prediction accuracy increased under specific conditions. For example, the researchers made their most accurate predictions about images that subjects reported seeing during the last seconds of their dreams—because we tend to remember (and more accurately report) the things we dream right before we wake up.
It’s amazing, and a little disquieting, to imagine a future in which our dreams have the potential to be entirely legible to the outside world. At the same time, this study throws into relief the complexity of dreams, and suggests it will be a longtime, yet, before our recorded dreams become just another variety of media. Maybe fMRI technology can tell that you dreamed about an old man and a dog walking together through forest. But what did it feel like to be in that forest, and what did the dog mean? That knowledge would seem to be safely yours alone, if it belongs to anyone at all.
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Leon Neyfakh is the staff writer for Ideas. Amanda Katz is the deputy Ideas editor. Stephen Heuser is the Ideas editor.
Guest blogger Simon Waxman is Managing Editor of Boston Review and has written for WBUR, Alternet, McSweeney's, Jacobin, and others.
Guest blogger Elizabeth Manus is a writer living in New York City. She has been a book review editor at the Boston Phoenix, and a columnist for The New York Observer and Metro.
Guest blogger Sarah Laskow is a freelance writer and editor in New York City. She edits Smithsonian's SmartNews blog and has contributed to Salon, Good, The American Prospect, Bloomberg News, and other publications.
Guest blogger Joshua Glenn is a Boston-based writer, publisher, and freelance semiotician. He was the original Brainiac blogger, and is currently editor of the blog HiLobrow, publisher of a series of Radium Age science fiction novels, and co-author/co-editor of several books, including the story collection "Significant Objects" and the kids' field guide to life "Unbored."
Guest blogger Ruth Graham is a freelance journalist in New Hampshire, and a frequent Ideas contributor. She is a former features editor for the New York Sun, and has written for publications including Slate and the Wall Street Journal.
Joshua Rothman is a graduate student and Teaching Fellow in the Harvard English department, and an Instructor in Public Policy at the Harvard Kennedy School of Government. He teaches novels and political writing.