New research shows that human brain waves might have another sense for detecting different magnetic fields. Normally, this is only seen in birds, fish and some other creatures, who use it for navigation, but scientists have thought that humans might have this magneto-reception.
Scientists exposed people to an Earth-strength magnetic field pointed in different directions, and they have found specific brain wave patterns that react to moving the field in a certain way. They reported their studies to eNeuro, an online publisher. In their findings, there is evidence that humans subconsciously react to the Earth’s magnetic field. They still do not know why or how our brain uses this information. During the experiment, 26 people sat down with their eyes closed in a dark, silent chamber lined with electrical coils. The coils changed the magnetic field in the chamber so that it stayed the same strength as Earth’s but the direction it was pointing could change. The test subjects wore an EEG cap that studied the electrical activity in their brains while the magnetic field moved in different directions, which mimicked the effect of someone turning in different directions in Earth’s unchanging field. They also had a control where the magnetic field didn’t move in the chamber.
Joseph Kirschvink, a neurobiologist and geophysicist at Caltech, studied alpha waves to see if the brain does in fact respond to changes in the magnetic field’s direction. Alpha waves normally dominate EEG readings while sitting but falter if the brain receives a sensory input. The changes in the magnetic field made the alpha waves act differently. If the magnetic field was pointed towards the floor (the Northern Hemisphere) or the field was turned counterclockwise so it turned from northeast to northwest, then alpha waves would dip by an average of 25%. This change is three times as strong as natural alpha wave changes in control tests. However, if the magnetic field turned to the ceiling (the Southern Hemisphere), there was no reaction.