For centuries, dreams have fascinated humanity, leaving us with lingering questions about why we dream and what purpose dreams serve. While various theories have been proposed over time, the mystery has remained largely unsolved—until now. New insights from neuroscientists are bringing us closer to understanding the function of dreams. According to a recent hypothesis published on May 14 in the journal Patterns, dreams may help our brains better generalize daily experiences.
Dreams, according to this groundbreaking theory, assist in broadening the brain’s perspective by avoiding overfitting to repetitive stimuli from our daily lives. As we go about our daily routines, the brain becomes highly attuned to specific patterns, much like artificial intelligence (AI) systems trained on a dataset. This new theory, however, suggests that dreaming serves to introduce randomness, allowing our brains to “zoom out” and gain a broader understanding of the world around us.
The theory, spearheaded by Dr. Erik Hoel, a research assistant professor of neuroscience at Tufts University, is known as the “overfitted brain hypothesis.” This hypothesis proposes that dreams correct errors caused by the brain’s overfamiliarity with daily life, helping it to better generalize and make sense of experiences. It’s an idea that has opened the door to an entirely new understanding of why we dream.
1. The Overfitted Brain Hypothesis: A New Way of Understanding Dreams
Dr. Erik Hoel’s overfitted brain hypothesis offers a new lens through which to view dreams. His theory argues that, much like AI systems, the human brain can become “overfitted” to specific stimuli, meaning it starts to expect and operate within the same patterns it encounters every day. As a result, the brain may struggle to generalize these experiences, making it difficult to adapt to new or unexpected situations.
In this view, dreams act as a corrective mechanism, introducing randomness to the brain’s processing. Dr. Hoel likens this process to how AI systems are trained. “There are many theories about why we dream,” Hoel says, “but I wanted to present one that takes the experience of dreaming seriously. It’s the very nature of dreams, in their strangeness and divergence from reality, that serves a biological function.”
This concept offers an innovative take on the age-old question of why dreams are often so bizarre. Rather than being random or meaningless, the strange, abstract nature of dreams is exactly what gives them their purpose.
2. Comparing the Human Brain to Artificial Intelligence
In his paper, Dr. Hoel draws an intriguing comparison between the human brain and machine learning models. Artificial intelligence systems are trained to perform tasks based on specific data. However, when these systems become too accustomed to a particular dataset, they begin to assume that the same patterns will apply everywhere. This phenomenon is called overfitting, where the AI performs well on the training data but struggles to adapt when presented with new, different datasets.
To combat this, data scientists often program a bit of chaos into the system. A common technique, known as “dropout,” involves ignoring certain data points during training. This forces the AI to focus on the bigger picture rather than getting caught up in minor details. In Hoel’s theory, dreams serve a similar purpose for the human brain, allowing it to generalize better rather than getting overly fixated on specific, repetitive stimuli.
He explains, “The brain inspired the original architecture of deep neural networks, so it’s no surprise that techniques used to prevent overfitting in AI bear some resemblance to what dreams may accomplish in our own brains.”
3. What Does This Mean for Our Understanding of Dreams?
With this theory in mind, the overfitted brain hypothesis suggests that dreams may help us achieve a more comprehensive and well-rounded understanding of our daily lives. Just as AI uses dropout to prevent overfitting, our brains use dreams to shake up the monotony of everyday experience, giving us a broader, more generalized view of the world.
Dr. Hoel goes on to describe how the brain crafts an unusual, distorted version of our waking lives during dreams. This phenomenon, he argues, acts as a biological “dropout,” helping us avoid becoming too attached to specific patterns and instead focus on the bigger picture. He writes, “It’s precisely the strangeness of dreams, their divergence from waking experiences, that gives them their biological function.”
4. Supporting Evidence for the Overfitted Brain Hypothesis
While the overfitted brain hypothesis is still in its early stages, there is already some evidence to support the idea. Research shows that people often dream about things they repeatedly experience while awake. For instance, if someone is learning a new task, their brain may dream about the task during sleep. According to Hoel, this suggests that the brain may be overfitting to the task during waking hours, and dreams serve to generalize this experience.
However, more research is needed to fully understand whether this is the primary purpose of dreams. Hoel emphasizes the importance of future studies that explore the differences between generalization and memorization in the brain, and how sleep deprivation might impact these processes. Such studies could shed further light on how dreams contribute to cognitive function.
5. The Concept of “Artificial Dreams” and Fictional Experiences
Interestingly, Dr. Hoel also speculates on the idea of “artificial dreams.” This thought came to him while considering the role of fictional works of art, such as movies, books, and virtual reality. He theorizes that these art forms might act as waking substitutes for dreams, providing the brain with the chaos it needs to prevent overfitting.
In particular, Hoel suggests that people might even create these external stimuli—books, films, and other forms of entertainment—as a way of staving off the effects of sleep deprivation. He argues that consuming fictional stories might help the brain achieve the same goal that dreams do: keeping life interesting by preventing overfamiliarity with daily experiences.
“Unlike AI, you can’t simply switch off learning in the brain,” Hoel says. “The brain is always learning new things, and that’s where dreams come into play. Dreams are there to ensure you don’t become too fitted to your model of the world.”
6. Dreams: The Brain’s Solution to Life’s Monotony
Dr. Hoel’s theory highlights the idea that dreams may exist to prevent the monotony of daily life from dulling our cognitive abilities. Without dreams, our brains could become stuck in familiar patterns, leaving us ill-equipped to adapt to new situations. As he puts it, “Life can be boring sometimes, and dreams help ensure you don’t become too rigid in your understanding of the world.”
In many ways, this theory of dreams aligns with the brain’s need to constantly evolve and adapt. By introducing randomness into our understanding of the world, dreams keep us from becoming too narrowly focused on the details of our day-to-day existence. They help us navigate a world that is ever-changing, ensuring we remain flexible in our thinking and open to new experiences.
7. A New Understanding of Dream Function
This fresh perspective on dreams offers a fascinating glimpse into the complexity of the human brain. Hoel’s overfitted brain hypothesis provides a biological explanation for why dreams are so strange and seemingly unrelated to our waking lives. The randomness of dreams is not a byproduct of sleep—it’s the brain’s method for expanding its understanding and keeping life from becoming too predictable.
Dreams, in this view, are an essential part of maintaining cognitive flexibility, allowing the brain to step back from the specifics of daily life and better understand the broader picture. As research into this theory continues, we may uncover even more clues about the mysterious role dreams play in shaping our perception of reality.
Final Thoughts on the Overfitted Brain Hypothesis and Why We Dream
The idea that dreams exist to prevent the brain from overfitting to the monotony of daily life offers a refreshing take on an age-old mystery. Neuroscientists like Dr. Erik Hoel are getting closer to understanding why we dream, and this new theory sheds light on how dreams might help us better navigate an ever-changing world.
As we continue to explore the function of dreams, the overfitted brain hypothesis provides a compelling explanation for the strange, abstract nature of our dream experiences. Future research may reveal even deeper insights into the role dreams play in helping us make sense of our lives, but one thing is certain—dreams are far more than just random, meaningless events during sleep. They are essential to how our brains learn, grow, and adapt.