Everyone's had it, that sensation of falling, wind in your hair, your stomach reliving your last rollercoaster ride, that split second of panic before waking. The symbolism of dreaming unites us like few other things. But do these images mean anything? And if not, what are they for?
Contemporary theories of dreaming have come a long way since Greek and Roman times, where dreams were interpreted as a supernatural communication, a kind of divine intervention that foretold the future. But dreaming remains one of the most controversial phenomena in modern psychology. While Sigmund Freud thought that dreams were a way for us to fulfill unconscious desires repressed from conscious awareness, others propose that they are merely epiphenomena - a feeble attempt at interpreting random signals generated by emotional and mnemonic structures in the brain. The most recent theory, and one that I find most compelling, argues that the dreaming brain acts as a virtual reality generator, helping us to learn about and make sense of the real world, road-testing its parameters in a closed environment. Though we might not fully understand the meaning behind dreams, we know a lot about the way in which we subjectively experience them. Decades of lab experiments and dream journals have revealed a hard truth: humans are more likely to experience fear than any other emotion when dreaming. One study found that fear accounts for 32% of all emotions experienced in our dreams, compared with just 6% for affection and eroticism. The most commonly cited themes include being chased, failing an exam, falling, having one’s teeth drop out, and being unable to find the toilet. Adding insult to injury, we’re more likely to encounter aggressive social interactions than friendly ones, with upwards of 40% of dreams containing at least one aggressive incident. So far this all seems to be painting quite a bleak picture: billions of brain cells mercilessly disrupting our all-important downtime. But does our waking behavior have any effect on what our minds get up to when we sleep? If so, it implies that we might be able to alter our dreams by changing our daytime activities. Scientists recently asked whether they could identify any meaningful relationships between waking life and dream content in a group of 587 university students. Amazingly, they found that individuals who were more mindful in their daily lives were less likely to experience negative emotions in their dreams. The researchers suggest that by being more mindful, we change the way in which the brain responds to stressful or anxious events in our lives. This, in turn might reduce the incidence of negative emotions in our dreams. We might guess that this is because individuals who are more mindful are also likely to have a smaller amygdala, a part of the brain associated with fear. But proving this theory is methodologically challenging. The required setup involves lying down in an MRI machine with a net of electrodes placed over the scalp. The MRI machine allows us to take detailed “snapshots” of the brain with the assistance of powerful magnets, while the net of electrodes allows us to infer when someone is dreaming. But if there’s one thing virtually guaranteed to give you bad dreams, maybe it’s sleeping in a small coffin-like chamber, while noisy machinery whirrs around you with a net of suction cups clinging to your scalp. Even if we can’t prove it conclusively yet, it’s a beguiling prospect: 10 minutes’ meditation in the morning wouldn’t just improve your day, but your night too.