By: Linda Geddes | Weird dreams train us for the unexpected, says new theory | Neuroscience | The Guardian
AI inspires hypothesis that sleeping human brain might try to break its overfamiliarity with daily data
It’s a common enough scenario: you walk into your local supermarket to buy some milk, but by the time you get to the till, the milk bottle has turned into a talking fish. Then you remember you’ve got your GCSE maths exam in the morning, but you haven’t attended a maths lesson for nearly three decades.
Dreams can be bafflingly bizarre, but according to a new theory of why we dream, that’s the whole point. By injecting some random weirdness into our humdrum existence, dreams leave us better equipped to cope with the unexpected.
Freudian theory: Sigmund Freud believed that dreams represent “disguised fulfilments of repressed wishes”, and are composed of manifest and latent content. Manifest content refers to the sights, sounds and storyline of the dream, while latent content is the symbolic meaning behind the dream, representing the unconscious wishes of the dreamer.
Memory consolidation theory: Perhaps dreams are just replays of past events. We consolidate our memories during sleep, and according to this theory, dreams are the reflection of that. Certainly, there is some evidence that specific sequences of neural firing observed while we are awake are sometimes “replayed” during sleep.
Threat simulation theory: This posits that dreams are an ancient biological defence mechanism, which enable us to practice overcoming threats. Essentially, they provide the dreamer with a virtual reality environment in which to practice important survival skills.
Activation synthesis theory: Maybe dreams are just a random string of memories thrown together. If so, they may provoke us to make new connections, or trigger creative epiphanies while we sleep.
Empathy theory: Dreams may not have evolved with a function, but gain one when we share them with other people. Similar to sharing of stories, dreams may serve to build empathy between people.
Emotion regulation theory: This proposes that dreams are constructed from our emotional history, and may serve to help us process and regulate our emotions.