The likelihood that humans can detect the Earth’s magnetic field is a discovery of a new human sense. It is called magnetoreception.
A study presents the hypothesis that some humans are sensitive to the Earth’s magnetic field. This is relevant to a discussion about our relationship with animals because up until now we have almost exclusively discussed a sensitivity to the Earth’s magnetic field in relation to birds, other animals and domestic cats (my favourite topic).
There’s been a lot of discussion about how domestic cats find their way home. The best proposition is that they sense the Earth’s magnetic field and use it like a compass to navigate. I think that this current research published on March 18, 2019 in the journal eNeuro supports the hypothesis that domestic cats are sensitive to the Earth’s magnetic field.
The study suggest that the human brain is able to detect the magnetic fields which are used by turtles to traverse the oceans. Mole rats also use the magnetic field to navigate in total darkness. Protozoa are also apparently sensitive to it.
The planet’s magnetic field is created by molten iron churning beneath the earth’s crust. In the study, 34 individuals were subjected to an artificially created magnetic field. The scientists detected shifts in their brain behaviour patterns. This indicated that some of the participants were processing sensory information.
When humans are resting their brains are in a state of “alpha rhythm”. This decreases when the brain detects a stimulus. This is known as alpha event -related desynchronisation. Scientists believe that when this happens brain cells are being used to process incoming sensory information.
They believe that the Earth’s magnetic field creates the same changes to the brain indicating that it detects the magnetic field. Four of the participants demonstrated responses during testing.
The participants, however, said that they could not tell when magnetic field changes occurred. However, it seems reasonable to suggest that humans, who are after all human-animals, have retained this ability given the fact that they were nomadic hunters.
I’m writing this short article because, as mentioned, there is a question mark over how domestic cats navigate over considerable distances when returning home for instance. This hypothesis about humans supports the magnetic field sensitivity argument in my view.