It may explain why some of us have a brilliant sense of direction, while others get lost all the time.

Many animals have the ability to sense magnetic fields: homing pigeons, turtles and even warthogs can sense which way is north.

But now scientists have discovered evidence for the first time that some humans may have a magnetic ‘sixth sense’ too - an built-in compass in that can pick up changes in magnetic fields.

The findings suggest that some of us may have an ability to navigate - and find the direction north.

Scientists have discovered evidence for the first time that some humans may have a magnetic ‘sixth sense’ too - an built-in compass in that can pick up changes in magnetic fields. This image shows scans that revealed the ability

In the latest study, published in the journal eNeuro, researchers exposed subjects to magnetic fields.

They then scanned their brains using electroencephalography (EEG).

In some individuals, the scientists at Caltech and the University of Tokyo found a change in brain waves that showed the brain was actively processing the information.

The researchers found a marked decrease in alpha waves in the brain when they exposed certain individuals to a magnetic field indicating ‘north’.

Alpha waves are given off when the mind is at rest. A dropping off occurs when the brain receives input from the senses.

The researchers write: ‘Our results indicate that human brains are indeed collecting and selectively processing directional input from magnetic field receptors’.

‘These data argue strongly for the presence of geomagnetic transduction in humans, similar to those in numerous migratory and homing animals.’

The authors say that evidence from the field of linguistics has indicated that humans may be able to pick up north by their senses alone.

For instance in many human languages - particularly among nomadic hunter gatherers - people use the cardinal points to locate things - north, south east and west - rather than ‘in front, back, left and right’

Many animals have the ability to sense magnetic fields: homing pigeons, turtles and even warthogs can sense which way is north. Experts scanned participants' brains using electroencephalography (stock image)

Some scientists have speculated ‘a human magnetic compass might be involved’.

In conclusion the authors write: ‘Given the known presence of highly-evolved geomagnetic navigation systems in species across the animal kingdom, it is perhaps not surprising that we might retain at least some functioning neural components, especially given the nomadic hunter/gatherer lifestyle of our not-too-distant ancestors.

‘The full extent of this inheritance remains to be discovered.’

But the authors warn that even if an individual can pick up magnetic fields, for most of us a lack of use has probably meant it is not very developed.

In addition, modern life is likely to play havoc with them.

For example, there are strong permanent magnets in headphones, most of which produce magnetic fields several times stronger than that produced by magnetic north.

The magnetic sense might work best in situations where other cues are not available such as at sea or in the air where disorientation is frequent, the authors suggest.