Magnetic field and brain

Some animals use the invisible magnetic field that wraps around our planet as a natural navigation system. It turns out, some people might also be able to sense our planet's magnetic field, though it's not clear why. In a study published in March, a group of researchers scanned the brains of 34 people who were told to sit in a dark test chamber with an artificial magnetic field. Brain analysis showed that four of the 34 participants showed a strong reaction to a shift in the magnetic field from northeast to northwest — but not the other way around.

Those four individuals showed a decrease in a brain wave that indicated that the brain picked up a signal, likely a magnetic one. It's not clear why some people showed a response to the magnetic field, while others didn't, and it's also not clear how the brain detected such signals. But prior research has found that the human brain contains lots of tiny magnetic particles, which might have something to do with it, according to the researchers.
Source:livescience.com