There you are, sitting front row of Miss Ryan's English class in your underwear, when in walks Chris Hemsworth holding a saxophone in one hand and a turtle in the other, asking you to play in his band. "Why not?" you say, taking the turtle before snapping awake in a cold sweat, the darkness pressing in as you whisper to yourself, "…WTF?" Decades – if not centuries – of psychological analysis have ventured to explain why it is our imaginations go on strange, unconstrained journeys while we sleep, with the general consensus being it has to do with processing experiences from our waking hours. That's all well and good, but seriously, do they have to be so … well, bizarre? Neuroscientist Erik Hoel from Tufts University has taken inspiration from the way we teach neural networks to recognize patterns, arguing the very experience of dreaming is its own purpose, and its weirdness might be a feature, not a bug.

Why we dream is one of science's most perplexing mysteries, but a neuroscientist in the US thinks he finally has the answer. Erik Hoel, a research assistant professor of neuroscience at Tufts University in Massachusetts, has taken inspiration from artificial intelligence (AI) for his theory. In a new report, he argues that the often hallucinogenic, nonsensical quality of dreaming is like throwing in new, unexpected data to a neural network. Professor Hoel calls this the'overfitted brain hypothesis' – and argues that it keeps human minds from'fitting too well to their daily distribution of stimuli'. This illustration represents the overfitted brain hypothesis of dreaming, which claims that the sparse and hallucinatory quality of dreams helps prevent the brain from'overfitting' to its biased daily sources of learning Neural networks are a subset of machine learning and are at the heart of deep learning algorithms.

Psychologists, neuroscientists and others have pondered the origin and role of dreams for time immemorial. Freud suggested that they were a way of expressing frustrations associated with taboos -- an idea that has long been discredited. Others have suggested dreams are a kind of emotional thermostat that allow us to control and resolve emotional conflicts. However, critics point out that most dreams lack strong emotional content and that emotionally neutral dreams are common. Still others say dreams are part of the process the brain uses to fix memories or to selectively forget unwanted or unneeded memories.