A person's fear of waking up during surgery is not so fantastic. Doctors from Finland we found out that we never completely lose consciousness under anesthesia.
The results of two studies on anesthesia were published by experts from the University of Turku. As physicians found out, partial consciousness remains even under a full anesthesia. "The brain during General anesthesia works more than we thought," said a practicing anesthesiologist at one of the clinics of Turku Harry Scheinin (Harry Scheinin).
Experts used the data of 47 patients who were under General anesthesia. Volunteers were administered one of two drugs widely used in surgery: dexmedetomidine and propofol. Participants received low doses of the drug, sufficient for loss of sensitivity. Volunteers who were under the influence of anesthetics shook or talked loudly with them, and also allowed to listen to a series of unpleasant sounds. Also, doctors monitored the brain activity of volunteers.
Having recovered, the majority of participants of experiment declared that they had vague dreams. According to physicians, echoes of the events with the person in reality reached consciousness of the person even under anesthesia. So, in one of experiments to volunteers allowed to listen to a series of sounds among which there were also those which they heard earlier under anesthesia. Judging by the EEG, the human brain reacted to the sounds heard earlier under anesthesia much faster than to unfamiliar sounds. That is, the brain processed acoustic information even under anesthesia.
In another experiment, volunteers under anesthesia were given to listen to the phases with bizarre endings, for example, "the bear walks on the moon" (instead of "the bear walks through the forest"). In some cases, the brain under anesthesia reacted to the unexpected word as if the person was conscious. However, when people woke up, they did not remember what they heard.
According to the researchers, all this proves that a person can not lose consciousness in full. The main thing that he loses under the influence of anesthesia — it's memories. However, as noted by experts, acquainted with the results of the study, in experiments, Finnish doctors used a fairly light anesthesia. To understand exactly how the human brain behaves with the usual doses of anesthetics for surgery, additional research will be required.