Turku, Finland – Where does our brain go when we go to sleep? A super network at the center of the brain can help solve the biggest scientific mysteries – how does human consciousness work? Scientists in Finland have discovered a single central network developed with the same activity regardless of whether a person normally falls asleep or loses consciousness due to anesthesia.
Researchers at the University of Turku conducted two experiments that for the first time came up with a link between the natural mechanisms behind human consciousness and how people react during sleep. In one study people medically examined brain activity under anesthesia, while another looked at how subjects responded naturally when they were asleep and when they woke up.
In addition to using brain-imaging techniques, the researchers also asked a series of questions to awakened participants. This includes topics such as whether the volunteer is aware of their surroundings or remembers any of their dreams.
“A big challenge is to design a set-up, where the brain data in different states differ only in terms of consciousness. Our study has uncovered many previous conspiracies, and for the first time, reveals neural mechanisms within connected consciousness, ‘said Harry Schin, chief investigator in a university publication.
The unconscious comes in many forms
Researchers say that natural sleep and experimental anesthesia are powerful research tools in the study of human consciousness. In a previous study, scientists were placed in a state of unconsciousness as opposed to a state of consciousness. Whether a person is conscious or not is often defined by their behavior. For example, some believe that a person who lacks meaningful answers is unconscious. However, studies show that being responsive does not mean that a person is unaware of his surroundings and is not necessarily unconscious.
A person who does not respond may still be aware of their surroundings, meaning they are still “connected”, while the other may be unaware even though he is experiencing their inner world and is “disconnected.”
In a new study, scientists sought to identify “state-specific patterns” in brain activity by looking at “connected” and “disconnected” states of consciousness. They aim to find out the overall effects of anesthesia and sleep by comparing different doses of drugs and different stages of sleep.
“This unique experimental design was the main idea of our study and enabled us to discern changes in the state of consciousness from the overall effect of anesthesia,” explains first study and anesthesiologist Annlotta Sh Schein.
Which parts of the brain form the super network?
Researchers discovered networks in the brain connected to human consciousness. They did this by measuring the brain activity of adult males as they fell asleep and went under anesthesia through a PET scan. This is an imaging test that allows doctors to see how your brain is working.
The researchers woke up mid-experiment to interview patients and confirm their state of connectivity, or to make sure how much they were aware of their surroundings. They discovered a change in connectivity in the critical network that connects many areas within the brain.
These regions include the thalamus (which shares motor and sensory signals with other parts of the brain), the cingulate cortex (emotion formation and processing), and the angular nucleus (spatial cognition, memory retrieval and attention).
Rewriting common beliefs
The study found that when a volunteer regained consciousness, his or her attachment and blood flow decreased. This is the case for both sleep and anesthesia, suggesting that the changes correspond to the combination rather than the effects of sleep or medications.
“General anesthesia makes normal sleep feel more than traditionally considered. This interpretation, however, is consistent with our recent electrophysiological findings in other anesthesia studies, ”says Harry Schein.
“Because of the minimal delay between awareness and interview, the current results significantly add to our understanding of the nature of the anesthetic state. Contrary to popular belief, successful general anesthesia does not require a complete loss of consciousness, as the patient’s experiences simply disconnect from what is going on in the operating room. That’s enough, “explains Analotta Sh Schein.
The conclusion appears in the journal J Neurosis.
The report was contributed by SWNS author Laura Sharma.
