What happens to our consciousness when we fall asleep? Study can solve one of the biggest scientific mysteries

TURKEY, Finland – Where does our brain go when we fall asleep? A supernetwork in the middle of the brain can help solve one of the biggest scientific mysteries – how does human consciousness work? Scientists in Finland have discovered a central nuclear network that has the same activity, regardless of whether someone goes to sleep normally or loses consciousness due to anesthesia.

Researchers from the University of Turku conducted two experiments that for the first time revealed the natural mechanisms behind human consciousness and how they relate to the way people react during sleep. One study examined brain activity of people who were medically anesthetized, while the other looked at how the subjects reacted while sleeping naturally and after waking up.

Along with the use of brain imaging technology, researchers also asked participants a series of questions when they woke up. These include topics such as whether the volunteer was aware of their environment or remembered any of their dreams.

‘A big challenge was to design a configuration where brain data differed only in terms of consciousness only in terms of consciousness. Our study has overcome many previous confusions and reveals for the first time the neural mechanisms underlying the connected consciousness, ”said Harry Scheinin, lead researcher, in a university statement.

Unconsciousness occurs in many forms

According to researchers, natural sleep and experimental anesthesia are powerful research tools in the study of human consciousness. In previous studies, scientists were stunned by the state of alertness versus a presumed state of unconsciousness. Whether someone is aware or not is often defined by their behavior. For example, some may assume that someone who does not have meaningful answers is unconscious. However, studies show that a person does not react does not necessarily mean that a person is not aware of his environment and that he is not necessarily unconscious.

A person who is unresponsive may still be aware of his environment, which means he is still ‘connected’, while another may not be aware but is still experiencing and ‘disconnected’ from his internal world.

In the new study, scientists wanted to identify ‘state-specific patterns’ in brain activity by looking at ‘connected’ and ‘disconnected’ states of consciousness. They were also aimed at discovering the general effects of anesthesia and sleep by comparing different doses of the drugs and different stages of sleep.

“This unique experimental design was the key idea of ​​our study and enabled us to distinguish the changes that were specific to the state of consciousness from the overall consequences of anesthesia,” explains the first study and anesthetist Annalotta Scheinin.

What parts of the brain does the super network consist of?

The researchers searched for networks in the brain related to human consciousness. They did this by measuring the brain activity of adult males while they fell asleep and came under anesthesia through a PET scan. This is an imaging test that allows doctors to see how your brain is functioning.

Researchers woke patients up during the experiment to interview them and confirm their state of connectedness, or how aware they were of their environment. They discovered that changes in connectivity are connected to an important network that connects several areas deep in the brain.

These regions include the thalamus (which shares motor and sensory signals with other parts of the brain), the cingular cortex (emotion formation and processing), and the angular gyri (spatial cognition, memory retrieval, and attention).

Rewrite general beliefs

The study found that these regions experienced less blood flow when one of the volunteers lost commitment and had more blood flow when they regained consciousness. This is the case for both sleep and anesthesia, suggesting that the changes correspond to the attachment rather than the effects of sleep or drugs.

‘General anesthesia looks more like normal sleep than has traditionally been thought. However, this interpretation agrees well with our recent electrophysiological findings in another anesthesia study, ”says Harry Scheinin.

‘Due to the minimal delay between the awakening and the interviews, the current results contribute significantly to our understanding of the nature of the anesthesia. Contrary to popular belief, complete loss of consciousness is not necessary for successful general anesthesia, as it is sufficient to simply disconnect the patient’s experiences from what is happening in the operating room, ”explains Annalotta Scheinin.

The findings appear in the journal JNeurosci.

SWNS author Laura Sharman contributed to this report.