New research suggests humans have a hidden ancient superpower -- or at least an unconscious sensory perception that we've yet to figure out how to use.
A number of animals, including migratory birds and sea turtles, have a geomagnetic sense that allows them navigate by tuning into the Earth's magnetic field. Now scientists from Caltech and the University of Tokyo have experimental evidence that humans also harbor a similar sense of magnetoreception.
"Aristotle described the five basic senses as including vision, hearing, taste, smell, and touch," explained Caltech geoscientist Joseph Kirschvink, in a release. "However, he did not consider gravity, temperature, pain, balance and several other internal stimuli ... geomagnetic field sensors should also be there representing not the sixth sense but perhaps the 10th or 11th human sense to be discovered."
Kirschvink and his colleagues built a special chamber designed to be isolated from radio frequencies, sounds, light and all other potential sensory stimuli. Participants in the experiment sat in silence in the dark for an hour while researchers measured their brain waves as the artificial magnetic field around the chamber was shifted.
The 34 study subjects consciously experienced nothing more than sitting in the dark. But the brain waves of many of them showed a different story, responding to the magnetic stimulation the same way brain waves respond to sights, sounds or touch.
"The fact that we see it in response to simple magnetic rotations like we experience when turning or shaking our head is powerful evidence for human magnetoreception," said study co-author Shin Shimojo, a Caltech neuroscientist.
The researchers found that the brain appears to not only detect geomagnetism, it also seems to have a pretty "smart" sense of the Earth's geomagnetic fields. The experimental data showed that the brain seems to be actively processing the magnetic information from our environment and rejecting input that seems obviously wrong.
When the researchers made the vertical component of the magnetic field point upward, which is the opposite of how we experience the Earth's magnetic field in the Northern Hemisphere, there was no corresponding change in brain waves. Basically, the brain appears to have self-filtered out information that it considers to be obviously in error. Repeating the experiment in reverse in the Southern Hemisphere could confirm this phenomenon.
A study detailing the results of the experiments is being published in the journal eNeuro on Monday.
The team believes that a likely explanation for how human magnetoreception works might involve a naturally magnetic mineral called magnetite, which has been found in small amounts in human brain tissue.
"As for the next step, we ought to try bringing this into conscious awareness," Shimojo said.
And just like that, Marvel's Magneto now has a more plausible origin story. Paging Professor Charles Xavier...