The human brain is capable of sensing the magnetic field?

For many animal species, such as migratory bird species and sea turtles, the magnetic field that surrounds our planet acts as a compass. But according to new research, the human brain can also sense magnetic fields.

According to scientistsów from the California Institute of Technology (Caltech) and the University of Tokyo, many people can unconsciously detect changes in the Earth’s magnetic field. The study, led by Joseph Kirschvink and Shin Shimojo of Caltech and Ayu Matani of Tokyo University, showed that human m wavesózgowe respond to controlled changes in the magnetic field.

Researchers say this is the first concrete evidenceód on the existence of a new human sense – magnetoreception. Their findings were published in the journal „eNeuro”.

Many animals have a sense of magnetoreception, so why not us? For example, honeybees, salmon, ¿ółows, birds, whales or bats use the geomagnetic field to help them navigate. It has long been thought that humans might have a similar ability. However, despite many studies, this has never been conclusively proven.

– Aristotle described five basic sensesów: sight, hearing, taste, smell and touch – mówi Kirschvink. – However, he did not consider gravity, temperature, bólu,równow and several other internal stimuli of theóIn, about whichówe know that they are part of the human nervous system. Our animal roots suggest that we should be capable of róalso to feel the magnetic field, which may represent no shósty, but perhaps the tenth or eleventh human sense of – adds.

To determine whether people sense magnetic fields, Kirschvink and Shimojo built an isolated chamber in which theórej they installed electromagnets that generate magnetic fields. The researchers asked the participantóin the study to sit for an hour in total silence and darkness. At the time, they made changes in the magnetic field in the chamber and measured m wavesózgowe participantów using electrodes placed at 64 locations on their heads.

In someóhe magnetic field was fixed in one direction in some experiments, while in others it was rotated. In still others, the chamber’s insulation was turned off and no magnetic field was generated, meaning that the participant was only exposed to the Earth’s natural magnetic field. Participants did not know whichóry experiment is ongoing.

The test was conducted with 34 peopleób of róThe different age groups and róethnic groups. During a given session, participants consciously experienced nothing more interesting than sitting alone in the dark. However, in many participantsóIn a study of the change in their m wavesózg correlated with changes in the magnetic field wokóthem.

The researchers focused primarily on measuring alpha waves in mózgu, które occur in the frequency range from 8 to 13 hertzów and are a measure of whether mózg is engaged, whether it is in resting mode. When the human mózg is uninvolved, the amplitude of alpha waves is high. When something attracts its attention, consciously or unconsciously, the amplitude of alpha waves decreases. It is also known that several other stimulióin sensory input, such as vision, hearing and touch, causes sudden drops in alpha wave amplitude in the first few seconds after a stimulus.

The experiments showed that in someórych participantóin which the amplitude of alpha waves began to drop immediately after magnetic stimulation, decreasing by up to 60 percent in a few hundred milliseconds, and then returning to baseline a few seconds after the stimulus.

– This is a classic, well-studied response of m wavesózg to sensory data, referred to as stimulus-related desynchronization or alpha ERD – mówi Shimojo. – Alpha-ERD is a strong neural signature of sensory detection and the resulting change in attention. The fact that we see this in response to simple magnetic rotations is evidence of human magnetoreception, she added.

Kirschvink mówi that it hopes this study can serve as a roadmap for other researchers interested in próbą repeatórows and extensions of the study. – Given the known presence of highly evolved systemsóin geomagnetic navigation in many speciesóin animals, it is not surprising that we could keep at least someóre functioning neural components, especially given the nomadic lifestyle of huntergatherersów-collectors of our not-so-distant ancestorsów. The full extent of this legacy remains to be discovered – evaluates.