Scientists at Caltech and the University of Tokyo have determined that many humans are able to unconsciously detect the Earth's magnetic field. The new study shows that human brain waves respond to changes in Earth's magnetic fields.
The research team led by geoscientist Joseph Kirschvink (BS, MS & # 39; 75) and neuroscientist Shin Shimojo of Caltech, as well as neuroeureneur Ayu Matani of the University of Tokyo suggest evidence of 39, a new human meaning that they call magnetoreception.
Their study is published by eNeuro magazine on March 18th. Scientists have studied the geomagnetic sense well because it is observed in migratory animals such as birds and sea turtles. Meaning helps their biological navigation system.
Despite extensive research on animal magnetoreception, scientists have not yet been able to determine whether humans also have this ability. "Aristotle described the five basic senses as including vision, hearing, taste, smell and touch," said Kirschvink, corresponding author of the eNeuro study and professor in Geobiology Nico and Marilyn Van Wingen.
"However, he did not consider that gravity, temperature, pain, balance, and many other internal stimuli that we now know are part of the human nervous system." Our animal ancestors maintain that the sensors geomagnetic field should also be present, which does not represent the sixth sense, but perhaps the 10th or 11th human meaning to discover. "
Maybe more sense to discover
The researchers used electroencephalography to record the brain activity of adult volunteers when manipulating magnetic fields. In the course of carefully controlled experiments, the researchers found a decrease in brain activity of the alpha band in some participants. 34 human participants from different ethnic backgrounds were tested.
During the session, participants received no stimulus; they simply sat in the darkness. However, despite the lack of knowledge or sign, many brainwaves had undergone modifications corresponding to the magnetic field manipulated around them.
"It's a classic, well-thought-out response, brain waves to a sensory input, called event-related desynchronization, or alpha-ERD," says Shimojo, professor of experimental psychology at Gertrude Baltimore and an affiliate faculty member. Tianqiao Institute and Chrissy Chen for research. Neuroscience at Caltech.
Research continues on various groups
The experiment was then replicated on the participants who responded strongly, this second study confirmed that these responses were tuned to the magnetic field of the northern hemisphere.
"Alpha-ERD is a strong neural signature of sensory sensing and the resultant change in attention, the fact that we see it in response to simple magnetic rotations, as we do when we are spinning or shuffling. the head, is a powerful clue to magnetorception.The great individual differences we have also found intriguing with respect to human evolution and the influences of modern life, "says Shimojo.
"As for the next step, we should try to sensitize that to consciousness." The team will continue its work to include other research groups. Future research could provide new insights into how humans and individuals have evolved to become this ancient sensory system.