DOSSIER - Vision and Dreams
Often complex, sometimes incomprehensible, our dreams continue to fascinate us. Many theories have tried to explain them, and that is not what we will do in this new dossier. What interests us here is to know what impact our vision has on our dreams. Much research has been done on this area and continues to be. So let's find out what it is.
Vision and dreams: bubbling brain activity
There are five phases of sleep . The fifth and final phase of sleep, which can be identified as deep sleep, is characterized by rapid eye movements . It also calls this phase the MOR.
The rapid eye movement (REM Rapid Eye Movement in English) is a neurological term used to describe a phenomenon occurring during this fifth phase of sleep. This fifth phase is better known as REM sleep . It is recorded using electroencephalography (EEG).
Dreams take place exclusively during this phase of sleep. But what happens during this one?
It turns out that the brain activity reaches a level equal to that which occurs when we are awake. It has been proven, with supporting research, that this brain activity during MOR is related to that which interprets visual signals while awake.
[ =] A study has even proved that humans are capable of having so-called lucid dreams. While this remains rare, we have been able to focus on subjects who had the possibility of knowing that they were dreaming.
The participants were instructed to tighten the fists at specific times of their dream. The researchers were then able to establish a link between eye movements and lucidity.
A strong link with our vision
There are many gray areas about dreams and, like any good scientific theory, not all scholars agree on the conclusions.
But they are unanimous on the fact that our vision plays a preponderant role in our dreams. Scientifically, as we have seen, these take place during this precise ocular phase . But there is another thing: if we can imitate the vision in our dreams and be aware of what we are dreaming, it is because it is the neurons of the primary visual cortex that are activated.
This role of vision does not end there. If our dreams are sometimes strange, even incomprehensible, they are the fruit of our emotions and our experiences. They are therefore strongly impacted by what we saw during the day.
Now, some researchers are trying to find out more by trying to obtain visual representations of dreams. Perhaps one day it will be possible to be able to view your dreams afterwards, as in some science fiction films. Researchers are also interested in the perception of colors in dreams. A perception that would be due, again, to our emotions.
It is therefore clear that, despite this deep sleep, our brain and our eyes have continuous activity. Paradoxical you say? In reality, to schematize, we must see this association as a projection of dreams. The signal sent by the brain is projected by our eyes in dreams. This allows us to "see" with closed eyes. Incredible, right?
What about the visually impaired?
Having understood all this, a question logically arises. If our dreams are impacted by our vision , and even more so if these are, for the most part, the result of what we have seen during the day, what about people who cannot see?
The first step is to separate people who have lost their sight during their lifetime from those who have been blind from birth. Today, it is widely recognized that the former can see in their dreams, since they had the perception of things.
So this would mean that those with congenital blindness should not dream. This is not entirely true. It was first recognized that blind people had fewer dreams than sighted people. And this seems to be correlated with the fact that their rapid eye movements are slower than those of sighted subjects.
Does this mean that they are unable to present visual content in their dreams? Studies have been conducted using alpha attenuation , an EEG frequency component of sleep considered to be an indicator of visual activity.
This study, in which congenitally blind participants were asked to draw the pictures of their dreams, showed results very similar to the group of sighted participants .
The two groups of subjects even presented strongly similar results regarding the graphical representation of dream imagery . The main difference between the two groups was in the rate of recall of dreams.
Blind people tend to remember their dreams less ( Only 27% vs. 42% for sighted) but they have visual content of their dreams and are quite capable of representing it graphically.
Vision yes, but not only
Explanations remain difficult to establish concerning this particularity, but some hypotheses stand out. Indeed, we know that our visual system being active before birth, it could be that the brain draws on these distant memories to allow this visual content.
The other possibility is of course the role of the other sensory faculties . Since our dreams are conditioned by our emotions and our feelings, it seems natural that all our senses are involved. If a sighted person "favors" sight because they have it, a blind person will rely on their hearing, smell, touch and taste to create emotions. And it is recognized that when meaning is lacking, others become stronger.
Our dreams remain mysterious and have not finished questioning us. Yet, thanks to scientific research, there is now no doubt that vision and dreams are clearly associated. In the future, it may be possible to unravel all the secrets. Meanwhile, whether we can see or not, they continue to fascinate us.