The sixth sense of human being has been proved for the first time. What is the sixth sense of human being
4hw.com.cn: Recently, our 'sixth sense' has been confirmed by authoritative experts in the United States. The sixth sense mentioned here is not the sixth sense of women, so what is the sixth sense? Let's learn about it through this article.
The scientific community already knows that birds can use the geomagnetic field for navigation. In addition, scientists have found magnetic sensing ability in many species in nature, and the magnetic sensing ability of organisms has always been called biological 'sixth sense' in the industry. But as such an advanced human being, there seems to be surprisingly no evidence that we can sense magnetic fields. On March 19, a team from the California Institute of technology published a study on eneuro, which gave the answer: we can not only sense the magnetic field, but also the brain will respond strongly to the changes of the magnetic field. In the following article, the research team personally tells us the wonderful process of the confirmation of the 'sixth sense' magnetic perception in the human brain.
In the field of biological magnetic induction, there has always been a problem, that is, does human have the ability to sense magnetic field? Before, biologists have proved that some animals have magnetic induction. They believe that this ability can help bees, turtles and birds navigate. Scientists have been trying to explore whether humans are also magnetic sensing organisms. In the past few decades, some studies have shown that humans have magnetic sensing, but some studies have shown that they can not repeat and confirm these results.
Why is the repeatability of the results so poor? This is mainly because in the past, the presence or absence of magnetic induction was almost determined by the subject's behavioral response. As far as our daily feelings are concerned, even if humans have magnetic sense, it is either very weak in humans or hidden in the depths of the subconscious. Therefore, when subjects make behavior, their brains will misunderstand this usually vague feeling, and even ignore it directly. Therefore, the research team from California Institute of technology used another new method to detect human magnetic sensing ability, and recently they finally obtained the first neuroscience evidence that humans do have magnetic sensing.
Invisible but extremely important magnetic field
The magnetic field around the Earth continues to protect us from outer space radiation, which is why we can point with a compass. At present, the mainstream speculation in the scientific community is that the earth's magnetic field is generated by the movement of the liquid earth's core. But in fact, the magnetic field on the earth's surface is very weak, and the magnet of the refrigerator is about 100 times stronger than it.
Creatures on earth are exposed to the earth's magnetic field, which always exists. These magnetic fields have different densities and directions on different parts of the planet's surface.
Over the past 50 years, scientists have found that hundreds of species in bacteria and animals can sense and respond to the geomagnetic field. Some insects, such as bees, respond as strongly to geomagnetism as they do to light, smell and touch. There are more vertebrates that can sense magnetic fields. Biologists have found magnetic sensing ability in fish, amphibians, reptiles, birds and many mammals. Dogs can also find hidden magnets after training. Generally, animals with magnetic sensing ability will use the geomagnetic field to complete homing and migration navigation, and cooperate with other sensory systems.
However, many people still disagree with these findings, because there is no physiological mechanism to prove that organisms convert geomagnetic field into neural signals. Subsequently, Heinz lowenstam, an American paleoecologist, found that the cells of a shellfish can build some tiny crystals, which have ferromagnetism, that is, tiny magnetite particles. This is also the first time that biological magnet crystals have been found in living organisms. Later, scientists have also found such crystals in bacteria, various living organisms and even human brain tissues. This has shown that it is likely that the human brain has magnetic sensing ability, but this evidence alone is not direct enough.
In the latest study published in ennuro, researchers have created a new method to try to prove this impossible thing. The researchers reconstructed and obtained a new Faraday cage. The Faraday cage itself is used to demonstrate the principles of equipotential, electrostatic shielding and high-voltage live working. The improved Faraday cage includes a set of triaxial coils in which researchers can use the current of wires to create a highly uniform controllable magnetic field. The researchers asked 34 participants to sit in the modified test room and recorded their brain wave activity with electroencephalogram (EEG).
Schematic diagram of human magnetic receiving test room of California Institute of Technology
In daily life, when some people rotate their heads, such as nodding up and down or turning their heads from left to right, the direction of the geomagnetic field in the environment does not change, but its direction relative to the skull will change. However, the subject's brain did not respond to this change, because the brain may automatically ignore this change in the process of issuing a turn around command.
The subject sits in the Faraday cage facing north, and the magnetic field in the Faraday cage may rotate clockwise (blue arrow) from northwest to northeast, or counterclockwise (red arrow) from northeast to northwest.
In the modified Faraday cage, the researchers can change the direction of the magnetic field relative to the brain without any signal from the brain to move the head. It's like someone else turning your head or body, or you're sitting in a rotating car. In these cases, your body can still determine your position in space and the change of magnetic field by receiving signals from the vestibule. In the study, the process of changing the magnetic field is similar to these events.
Capture human magnetic signals
When the subjects' magnetic field in the Faraday cage was changed in the study, they did not have any obvious feeling. On the other hand, the subjects' EEG was not so calm. The data showed that specific magnetic field rotation could trigger strong and repeatable brain responses. In EEG, one is called alpha- ERD pattern, which occurs when an individual suddenly finds and processes a sensory stimulus. In this study, the subject's brain seems to have 'paid attention' to the unexpected change in the direction of the magnetic field, which triggers the & alpha; Wave reduction, which is typical & alpha- ERD mode. This has also become strong evidence that the human brain can feel and respond to magnetic field changes.
In addition, the subject's brain will respond only when the experimental magnetic field is in the same direction as the environmental magnetic field. For example, the experiment is carried out in Pasadena, California, where the geomagnetic field will pass through the human body at an angle of 60 degrees in the vertical direction. Then the subject's brain will respond only when the magnetic field is released in the Faraday cage, No matter how the magnetic field in other unnatural directions changes, the brain will not react. Researchers believe that this response is closely related to natural stimuli and may reflect a biological mechanism of natural selection.
Previously, other researchers have confirmed that the animal brain can filter magnetic field signals. They only respond to the magnetic field in their living environment, and automatically filter others that are too far away from the natural magnetic field. This decision is wise, because those unnatural magnetic fields are likely to come from magnetic anomalies - for example, magnetic fields generated by lightning attacks or magnet deposits on the ground.
Previous studies in birds have shown that once the geomagnetic field intensity deviates from the past by 25%, robins will stop using the geomagnetic field to complete biological functions such as navigation. This may also be the reason for the failure of previous human experiments. In the past, in order to prove that the human brain can feel the magnetic field, researchers thought that by increasing the intensity of the magnetic field, subjects could better feel the magnetic field. But in fact, in the process of increasing, the subjects have long directly ignored this part of the magnetic field, because it is too different from the natural environment.
In addition, this study also refutes other relevant electromagnetic induction mechanisms of human biological magnetic induction to a certain extent, indicating that human beings do not distinguish the direction through electromagnetic induction, which also denies the so-called 'quantum Compass' or' cryptochrome 'mechanism popular in the recent literature on animal magnetic induction. So far, the latest research has led us to speculate that humans not only have 'magnetic sensors', but also work normally to send signals to the brain, which is a previously unknown sixth sense in the human subconscious. In the future, more functions of human magnetic induction need to be further explored by scientists