What happens in our brain while we sleep?

Since the arrival of the Covid-19 pandemic, sleep has changed around the world, fundamentally in two ways

Since the arrival of the pandemic Covid-19 Sleep has changed around the world, fundamentally in two ways. For most people, this pandemic has meant a period in which The episodes of insomnia have increased, their sleep is more restless or fragmented, and there are more nightmares.

"This It is not surprising since many people have more anxiety about their future, fear of contagion or unemployment with this pandemic., as well as depression due to loneliness and the economic difficulties that we must face at this time," underlines Sidarta Ribeiro, a Brazilian neuroscientist, author of more than 100 scientific articles and 5 books, as well as professor of Neuroscience and vice director of the Brain Institute. from the Federal University of Rio Grande do Norte (Brazil).

With this, Ribeiro explains that While we sleep our brain recovers from the arduous activity of the day, cleanses toxins, replenishes biomolecules, produces hormones and restores neuronal connections. "Consequently, Memories are profoundly modified by sleep so that they are stored for posterity, are permanently erased, or mixed to generate new ideas. There are four different phases throughout a night of sleep, including rapid eye movement (REM) sleep, when sleep reaches a peak. REM sleep dominates the second half of the night and is very important for emotional processing and creativity," maintains this specialist.

For many people around the world, dreams have no function, he notes when, in his opinion, many do not even remember their dreams and much less talk about them with family, friends or colleagues. "However, dreaming is as natural as breathing and eating, and of great importance for the cognitive flexibility that underlies adaptation to challenges," warns the Brazilian neuroscientist.

Regarding how a dream is configured, Ribeiro indicates that they can be greatly affected by our attitude towards them: "In Western culture, the dream has been cornered and degraded, and when dreams are remembered, it is generally like an involuntary experience, something passive that happens to dreamers but is not caused by them."

On the contrary, he states that Among peoples who value and practice the art of dreaming, such as Native American and Australian populations, dreams are active and intentional opportunities to travel, solve problems, and learn something new.. "Dream shaping is a possibility every time you fall asleep, but it takes a lot of practice to take full control of your dreams, become lucid within them, and create scenarios and outcomes," he says.

Asked why we dream what we dream, Ribeiro acknowledges that dreams arise from the unconscious, that is, from the enormous collection of memories that we form, modify and transport over time.

"While dreams reflect the electrical activation of neurons involved in the encoding of specific memories, they also They are influenced by dopamine, a neurotransmitter that allows us to seek rewarding stimuli and avoid aversive ones., at the same time as a key mechanism for the production of desires and fears. Sometimes dreams simulate wishes or fears that become reality, and when that happens, we are truly amazed by them. On other occasions, however, dreams seem noisy and not very relevant," acknowledges the Brazilian scientist.

As for the why we only sometimes remember what we dreamed, states that during REM sleep, the neurotransmitter norepinephrine is not released in the brain. "As a consequence, it becomes very difficult to retain memories. When we wake up in the morning there is no norepinephrine available, the images from the last dream are faint and disappear quickly if we move, start a conversation or check email. "If one wants to remember their dreams well it is important to understand the key importance of producing a dream report before leaving bed," she highlights.

On the other hand, it highlights that, probably, we start dreaming since we are embryos inside our mothers' bellies. "From this moment on, whether during sleep or wakefulness, the dream never truly stops. However, just like the stars are always in the sky but cannot be seen during the day due to the overwhelming glare of the sun, it is difficult to notice dreams with your eyes wide open," he admits.