This is how science explains near-death experiences: "The most widely accepted view is that they are hallucinations."

One of the great mysteries of science is what happens after death. There is no certainty about what happens, but we do have testimonies from people who have been close to death or clinically dead. These are called 'near-death experiences'.

Many of the testimonies tend to coincide with scenes such as a light at the end of a tunnel , the body levitating or flying, peaceful natural settings, or sensations of intense well-being. But what does science say?

Ken Drinkwater, a doctor of psychology at Manchester Metropolitan University, has researched the subject. He told the Mirror : "A near-death experience is a profound psychological event with mystical elements. It usually occurs in people close to death or during situations of intense physical or emotional pain, but can also occur after heart attacks or head trauma, or even during meditation and fainting. They are surprisingly common: a third of people who have been close to death report having experienced one."

"Common features people report include feelings of contentment, psychic detachment from the body (like out-of-body experiences), moving quickly through a long, dark tunnel , and entering a bright light," Drinkwater says.

The researcher states that neuroscientists Olaf Blanke and Sebastián Diéguez have proposed two types of near-death experiences. Type one, associated with the left hemisphere of the brain, presents an altered sense of time and impressions of flying. Type two, which affects the right hemisphere, is characterized by seeing or communicating with spirits, and hearing voices, sounds, and music.

"While it's not clear why there are different types of near-death experiences , distinct interactions between brain regions produce these distinctive experiences," Drinkwater continues.

"The temporal lobes also play an important role in near-death experiences. This area of ​​the brain is involved in processing sensory information and memory, so abnormal activity in these lobes can produce strange sensations and perceptions," the expert explains.

According to Drinkwater, "Scientific explanations for near-death experiences include depersonalization , which is a feeling of separation from one's body. Science author Carl Sagan even suggested that the stress of death produces a memory of birth, suggesting that the 'tunnel' people see is a reimagining of the birth canal."

But there are other explanations. Some researchers claim that the endorphins released during stressful events could produce something similar to a near-death experience, particularly by reducing pain and increasing pleasurable sensations. Similarly, anesthetics like ketamine can simulate characteristics of near-death experiences, such as out-of-body experiences.

"Researchers have also explained near-death experiences through cerebral anoxia, a lack of oxygen to the brain. One researcher found that pilots who experienced unconsciousness during rapid acceleration described characteristics similar to those of a near-death experience, such as tunnel vision," Drinkwater says.

"Lack of oxygen can also trigger temporal lobe seizures, which cause hallucinations . These can be similar to a near-death experience," he adds.

"But the most widely accepted explanation for near-death experiences is the dying brain hypothesis. This theory proposes that near-death experiences are hallucinations caused by brain activity as cells begin to die," the British researcher adds.

Since these occur in moments of crisis, this would explain the stories told by survivors. The problem with this theory, although plausible, is that it doesn't explain the full range of characteristics that can occur during near-death experiences, such as why people have out-of-body experiences.