From now on, reflections on where our lead us will no longer seem so hazy. Researchers from Harvard University have found preliminary evidence that dreams play a significant role. They prepare the brain for learning and memory retention.
A team of researchers led by neurobiologist Nghia Nguyen set out to understand how the dreaming process occurs at a neurobiological level and whether these moments of quiet contemplation are important for learning and memory.
Tested on Mice
It might be hard to imagine a dreamy mouse. Nevertheless, scientists have long studied the state of daydreaming in these rodents. In a recent study, the Harvard team discovered that when mice dream (or quietly reflect on what they saw earlier that day), their brains reboot in a beneficial way. Specifically, they become primed for memory and learning.
This hypothesis will need further testing in future studies. However, it is already clear that when mice are shown a black-and-white checkered pattern, they can visualize the image in their mind’s eye even after it has disappeared from view.
The study involved 13 mice, which were shown two different black-and-white images in a calm setting 64 times a day. Each image was displayed for two seconds. The experiments were repeated over several days. During this time, the team monitored the electrical activity of 7,000 neurons in the mice’s brains, including nerve cells from the visual cortex and hippocampus (an area closely associated with memory consolidation).
Each of the two images ultimately triggered different patterns of neural activity in the lateral visual cortex of the mice. This part of the brain is involved in recognizing objects and features of shapes.
The results showed that the mouse’s brain encodes each image using different patterns of neural activity. But what is particularly interesting is that after the images were replaced with a blank computer screen, the visual cortex of the mouse’s brain sometimes reactivated, stimulating a pattern of neurons similar to that of the distant image.
This brief reactivation of the visual cortex was often accompanied by sharp bursts of activity in the hippocampus. This indicates that the brain effectively encoded visual information despite the absence of a stimulus.
Subsequently, the brain’s activity when viewing the image became identical to the activity during dreams about that image. This suggests that dreams strengthen some neural connections while weakening others, creating a more efficient overall response to stimuli.
Conclusions Drawn by Scientists
The dreaming effect, where the visual cortex is engaged in visualizing an image that is no longer present, occurred exclusively when the mouse was unstimulated and in a calm, relaxed state. This was indicated, in part, by its small pupils, as reported by Science Alert.
This unstimulated dreamy state, according to the scientists, may have an effect similar to sleep, which consolidates memories and enhances learning.
According to neurobiologist Mark Anderman, a co-author of the study, dreams are extremely important for brain plasticity. Scientists believe that their findings may also apply to the human brain. However, this will need to be verified in future research.
The results of the study were published in the journal Nature.
At the same time, some scientists warn about the potential dangers that dreams may conceal. For instance, dreaming too much or dreaming about negative things could adversely affect a person’s cognitive abilities, such as attention and short-term memory.
Photo: pixabay.com
