People say other people’s dreams are boring, but what if the problem is technology? As a sense-conveying device, human speech is subpar, prone to gaps, stutters and falsifications, intentional or otherwise. If you could just literally show someone your dreams—suck them out of your skull and toss them onto the nearest screen—people might not roll their eyes when you tried to talk about them. Dream-movies have of course been sci-fi fodder forever, but with so many sci-fi staples verging on (or already present in) reality, it’s worth wondering if we’re any closer to experiencing them. For this week’s Giz Asks, we reached out to a number of experts to find out.

This story was originally published on November 16, 2020.

Professor of Ophthalmology, Neurology, and Physiology & Pharmacology, whose research bridges perceptual, oculomotor, and cognitive neuroscience

There is no theoretical barrier to the possibility of accessing the contents of someone’s dream, and reading it out, and providing data—visual and emotional content. Our dreams are neural activity in our brain; there’s nothing special about them that doesn’t affect every other emotional or perceptual experience we have in our waking lives. There is no particular circuitry or brain region that is activated during dreams but not in waking life. The big caveat is not the technology, but the fact that we still don’t really know the neural code; we still don’t know how conscious experience is encoded in the brain. The limits that make it impossible to share dreams today are the same ones that make it impossible to say, download our consciousnesses onto a computer. It doesn’t matter how fast technology progresses if we still don’t really understand the underlying neurophysiology. We still can’t really decode experience. There are theories, but fundamentally we lack consensus. There’s still significant debate in the field about whether, say, the prefrontal cortex is critical for conscious experience. We’re really far behind—I think we’re talking about decades here, rather than years. But one day, if we do understand what’s going on with the biology, and the technology exists, there’s no reason why we couldn’t download our consciousnesses onto a computer and live forever—or, alternately, share our dreams. “It doesn’t matter how fast technology progresses if we still don’t really understand the underlying neurophysiology. We still can’t really decode experience.”

Professor, Psychiatry, Harvard Medical School, whose research focuses on sleep

“Ever” is a very long time, but I think the answer, at least for the lifetime of anyone visiting your website is, “Nah, not a chance!” Think about it—it’s almost impossible to share your thoughts with someone else verbally. As soon as you get started, twenty new threads open up, and you have to choose just one. But they’re all there as part of your “thoughts.” The best they’ve been able to do with fully awake individuals is put them in an fMRI scanner and figure out whether they’re looking at a face or a tool. On a more philosophical level, your thought, and your dreams, are always embedded in your overall memory networks and life experiences. You can’t “walk in someone else’s shoes” by just putting them on and hiking on down to the mall. “The best they’ve been able to do with fully awake individuals is put them in an fMRI scanner and figure out whether they’re looking at a face or a tool.”

Research assistant at the MIT Media Lab, whose work focuses on brain science

Like so much of science, the question is a door to more doors. To share dreams we have to first define them, draw some kind of boundary around the dream—is it the visuals that define the dream, is it sight we want to share? If so, does a co-occurring image of my mother in both of our minds satisfy the notion of a shared dream? I don’t think so. Dreams are an amalgam of memory, they’re internal explorations of our networks of meaning, they’re concepts always embedded in personal context. So the same sensory stimulus in two minds may be an entirely different experience. That being said, we could ask if we’re ever watching the same movie, even while awake and sharing a couch… philosophically it’s a messy question Practically, it’s less messy. There have been strides already at decoding the visuals from a dream using brain imaging. Others have shown we can communicate from within a lucid dream, using eye movements to communicate across states of consciousness. And our work at Fluid Interfaces has shown we can incubate specific themes in dreams. On the surface level, we are closing the gap between the personal space of the dreamscape and the outside observer. But I think that gap remains a kind of Zeno’s paradox, because ‘experience’ is always going to be there, pestering scientists even as we create objective tools to capture, observe and recreate the dream. We cannot share a whole dream without sharing a whole self. “To share dreams we have to first define them, draw some kind of boundary around the dream—is it the visuals that define the dream, is it sight we want to share? If so, does a co-occurring image of my mother in both of our minds satisfy the notion of a shared dream?”

Professor, Philosophy, University of York, whose research focuses on dreams, among other things

Research Associate, Philosophy, University of York

Besides the innocuous sense in which we communicate our dreams, there are at least two interesting senses of dream-sharing: to have the same dream (co-dreaming); and to view another’s dream, perhaps through advanced technology (dream-scanning). Examples of dream-sharing can be found in some contemporary African cultures, where one can ‘dream for’ another person, or even ‘triangulate’ (in dreams that relate messages from one party, through the dreamer, to a third). They also appear in ancient civilizations (Mesopotamia, Egypt, and Greece), including cases in which the same important dreams would occur in both patient and priest on the same night (symptoma). On the prevalent view in contemporary Western cultures, dream-sharing in these ways seems impossible, barring coincidence, suggestion, or dream-scanning. On that view, dreaming is a fundamentally private (sleeping) experience that can only currently be shared through (waking) communication: the experience itself occurs in isolation. Our research suggests that the prevalent Western view of dreaming is wrong. It doesn’t easily explain familiar sleep phenomena such as pre-cognitive (‘alarm-clock’) dreams; the incorporation of low-level perception and interoception into dream content; or even how common foods can cause bad dreams. Instead, we think dreams are constructed from a number of sources—cultural and social effects, bodily sensations, and perception—primarily as one wakes up. On this alternative view, there is no fundamentally private experience behind our dream reports. If we are right, dream-scanning wouldn’t reveal much. We predict that information one might gain from scanning the brains of sleeping people will only correlate very loosely with their dream reports because what people report dreaming is influenced by so many other factors, such as cultural norms and social expectations. There is hope for the other sense of dream-sharing, though. In principle, to initiate a ‘similar’ dream in more than one person one might try to induce the same physiological and environmental changes in those persons while they sleep. But differences in age, health, diet, social factors and cultural associations might still lead to differences in dream content, so one would have to pick one’s subjects carefully. “There is hope for the other sense of dream-sharing, though. In principle, to initiate a ‘similar’ dream in more than one person one might try to induce the same physiological and environmental changes in those persons while they sleep.”

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