What happens when we dream is something that has fascinated and eluded philosophers and scientists alike for thousands of years. How do our ocular systems play a role in what we see in our dreams? Does this differ for individuals who are not sighted? A neurological study from Tel Aviv University may show how the brain’s visual system plays an integral role in the world of dreaming, while a separate study from the University of Copenhagen explores how sight and dreams are related in people with blindness.
The Tel Aviv University study is the first of its kind to examine brain cells during the dreaming stage. What scientists found was that the rapid eye movements (REM) that occur when we're dreaming are virtually identical to how our eyes function when we're awake and processing images. The research found that our eyes are responsible for "changing scenes" when it comes to our dreams and that the visual component of dreaming is far more complicated than scientists once thought.
The study also concluded that the neurons in our brain behave in a similar fashion whether we're seeing an actual image or simply imagining it in our mind. This means that your eyes aren't scanning images in your dream; they're reorienting your visual thoughts, serving as a kind of reset switch for whatever scene you're dreaming about.
According to Dr. Yuval Nir, one of the head researchers on the project, the effect is similar to how a slide projector functions: your brain sends a signal, and your eyes switch to the next slide in the dream.
This relationship could explain why blind people also move their eyes during REM sleep. Despite being unable to see images when they're awake, a blind person's brain can process acoustic and emotional information, which their eyes react to, indicating a change in scenery within the dream world.
While the study has provided a small glimpse into the human brain, one of the biggest questions remains: Why do we dream at all, and what larger mental and physical purpose does it serve? For Dr. Nir and his team of researchers, the answer to that mystery will likely remain the stuff of dreams.
The study from the University of Copenhagen explored the dream content of congenitally and late blind individuals to establish if there is a direct correlation between sight and dreams. The research discovered that, compared to the sighted controls, blind participants had fewer visual dreams. Interestingly, those with congenital blindness reported more nightmares than other study participants.
So what does that mean? According to this study, sight and blindness both play significant roles in how people dream. Those with sight will have more visual experiences in their sleep, while blind people will often experience more with their other senses, similar to their daily life.
Want to learn more about how your eyes work in your sleep? Visit this blog about rapid eye movement (REM) and how we can use it to our advantage.