What part of the brain do dreams come from?

In this article we will answer the question “What part of the brain do dreams come from?”. We will talk about research on the subject to find the answer to which part of the brain dreams come from.

What part of the brain do dreams come from?

Dreams form in the temporal lobe of the brain. This region is in charge of building, imagining and recreating memories.

Dreams occur during the REM (rapid eye movement) stage of sleep, the lightest and, in which, although we do not realize it, we quickly pass between sleeping and being conscious.

Dreams occupy 95% of the REM phase time

In the REM stage, the regulation between sleeping and waking is carried out by the reticular activation system, a circuit that goes from the brain stem, through the hypothalamus to reach the cerebral cortex.

It is the cerebral cortex, responsible for generating dreams, and which is very active while we are in the REM stage.

From there also comes the content of our dreams that, although they are fantasy, come from our own experiences. The fact that we see images when dreaming is in the activity of the visual cortex.

Another system that is activated during sleep is the limbic system.

We could say that our dreams are a composition created by different parts of our brain.

The limbic system, which regulates emotions, is active while we dream, and the amygdala, a structure responsible for feelings of fear and anxiety, contributes its own.

That is the reason why our dreams can be positive or turn into nightmares.

Dreams are not usually logical and there is a reason for this: the least active areas of the brain are those of the frontal lobes, precisely those in charge of reasoning, so the illogical can seem normal when sleeping, but strange once we wake up.

The brain on vigil

Maintenance of wakefulness is mainly due to the tonic activity of the catecholaminergic and cholinergic neurons of the activating reticular system. Histaminergic and peptidergic projections from the posterior hypothalamus also facilitate wakefulness. 

The activity of the sensory and sensory systems (visual, auditory) also contributes to the maintenance of wakefulness. 

Through the posterior area of ​​the bulb, where the blood-brain barrier is less active, some substances in the bloodstream such as adrenaline can contribute to the activation of the reticular system.

The brain in NOREM sleep

Serotonergic nuclei of the raphe of the brainstem, as well as the nucleus of the solitary fasciculus, the thalamic reticular nucleus, the anterior hypothalamus and nuclei of the preoptic area and the basal forebrain, are decisively involved in the genesis of slow sleep or NREM. Serotonergic neurons block motor activity and the intensity of sensory input. 

Other inhibitory neurotransmitters include adenosine and g-aminobutyric acid (GABA), as well as various peptides. 

The progressive deactivation of the activating reticular cholinergic system allows the appearance of recurrent thalamocortical rhythms that give rise to the “sleep spindles” and to the slowing of the EEG.

The brain in REM sleep

The regulation of REM sleep is even more complex, since physiologically antagonistic phenomena occur at the same time, such as a profound decrease in alertness with a state of EEG activation or intense motor inhibition with generalized hypotonia together with rapid eye movements and other phasic motor activities (different in the different species).

Dream Factory

As can be seen, dreams are the product of a joint work of different areas of the brain, each providing control of some function.

Depending on your activity, we may have a pleasant sleep or suffer from nightmares.

In their experiments, the researchers were able to locate the areas involved in the dream process with such precision that they could ‘guess’ the exact moment when the volunteers were dreaming.

They achieved this by observing the distribution of the different types of brain waves, generated in the various phases of sleep.

The “factory of dreams” would be just above the nape of the neck, at a fairly superficial point.

Researchers have called it a hot zone or posterior cortical hot zone.

“It is an area that becomes very active when we begin to dream,” explains Francesca Siclari, a neurologist at the Hospital of the University of Lausanne, among the coordinators of the research

.

Investigation 1

During the experiment, 32 volunteers volunteered to sleep in the laboratory, with electrodes attached to their heads, and to be awakened several times during the night, when the screens revealed interesting sequences.

Finally, they had to tell if and what they were dreaming at that moment.

In total, more than a thousand awakenings were caused and the dream activity was found to coincide with a reduction of the low-frequency waves, typical of sleep, in the hot zone.

The correlation between dreams and the decrease in these waves is so strong that, by looking at the traces of the EEGs, the researchers were able to guess whether that person was dreaming in 91% of the cases.

In this way they were also able to find out how much dreams really are: from the tests carried out, it turned out that this activity occupies 95% of the entire REM phase and 71% of the non-REM phase.

Hours and hours of “recording”, of which we only remember a few minutes.

Why do we forget dreams?

At present, it is thought that the production of dreams is associated with memories and the region of the hippocampus, an area located under the cerebral cortex, with an important role in memory.

• Landscapes and situations that we perceive in dreams are produced arbitrarily. All this is generated by our implicit memory, the same one that we use to do things automatically and that is responsible for relating abstract elements in our mind.

• Our memory works by association of ideas. Only when we associate something with a global situation can we remember it.

This is the reason why, when we dream, our brain constructs complex narratives and does not remember isolated elements.

Memories are formed, first, in the hippocampus, and then they are passed on to other parts of the brain, such as the neocortex.

This synchronization, which occurs in our conscious state, is not easy to occur during sleep. Therefore it is difficult to remember what we dream.

Investigation 2

In a test with 10 subjects, the ability to recall a dream was found to be related to increased activity during sleep in the prefrontal cortex, the area associated with memory.

Matthew Walker, a neuroscientist at Harvard Medical School and author of the book “Why We Sleep,” considers that different states of sleep serve to consolidate three different types of memories:

  • The spatial ones (which are formed by moving in a labyrinth or in a virtual city) –
  • Declaratives (which fix communicable knowledge with words) are consolidated, like the previous ones, during slow wave sleep –
  • Memories with a strong emotional component are developed and established during the Rem phase, the most active

The truth is that not everything is lost and history is full of problems solved at dawn.

After a dream, Dr. Otto Loewi woke up during the night and scribbled some reflections on a piece of paper.

The next morning he realized that he had written the basic concepts of the theory that would change the history of medicine: chemical neurotransmission.

Which he later demonstrated and for which he won the Nobel Prize in Physiology in 1936.

More recently, Larry Page, the co-founder of Google, said the idea of ​​a search engine with Google features came to him in a ‘lived’ dream, while Paul McCartney got the melody for the song “Yesterday” after dreaming it

Dreams really exist?

Another important point in Siclari’s research concerns the way the brain behaves during sleep.

In both REM and non-REM phases, an increase in high-frequency brain waves has been seen in normally active areas during the awake state, as if the person were actually experiencing what appears in their dreams.

“It is the proof,” says the neurologist, “that sleep is, for the brain, a real experience and not just something we invent when we wake up.”

According to the researchers, the fact that the dream experience has an observable neurological basis reinforces the theory that dreams can also be defined as experiences in which consciousness is active.

And if the activity in the hot zone is a spy on the brain’s ability to experience experiences despite sleep and immobility, the discovery could have medical applications as well.

In people with anesthesia or in a coma, Dr. Siclari says her study can provide new guidelines for evaluating consciousness. And it also means there’s something real about brain dreaming, and not something we imagine when we wake up.

FAQS: What part of the brain do dreams come from?

How long should the REM phase last?

This is when we dream, and if they wake us up, we remember them. A complete sleep cycle, from stage I to REM, usually lasts between 90-110 minutes, generally having five cycles throughout the night

What is the reason why we dream?

Experts, such as Sigmund Freud, argued that dreams exist to satisfy the desires that each person has, or that they can also be a faithful and symbolic reflection that takes over the mind, dreams and desires of the human being.

What is REM and Nomor sleep?

REM sleep is the most superficial stage of sleep; during it, the person can be easily awakened. During several hours of normal sleep, a person will go through various stages of sleep including REM sleep and the four non-REM sleep stages (shallow to deep sleep).

How many hours should a person sleep?

Younger adults (18-25 years old): 7-9 hours a day is your optimum sleep time. Adults (26-64 years): the same range of sleep needs is maintained as in the previous case. Older people (over 65 years): the healthiest thing for them is that sleep occupies 7-8 hours a day.

What are the benefits of deep sleep?

The body relaxes while we sleep, and this facilitates melanin and serotonin development. The effects of stress hormones (adrenaline and cortisol) are counteracted by these hormones and enable us to be happier and emotionally stronger.

References

Neurobiol Sleep Circadian Rhythms. 2018 Mar 1;5:68-77. doi: 10.1016/j.nbscr.2018.02.003. eCollection 2018 Jun. Sleep homeostasis and the circadian clock: Do the circadian pacemaker and the sleep homeostat influence each other’s functioning? Deboer T1.

Rados, R., & Cartwright, R. D. (1982). Where do dreams come from? A comparison of presleep and REM sleep thematic content. Journal of Abnormal Psychology, 91(6), 433.

How Do Brains Dream? (2019). Retrieved January 23, 2021, from Psychology Today website: https://www.psychologytoday.com/intl/blog/sleepless-in-america/201906/how-do-brains-dream

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