Can Humans Sense Magnetic Fields?

Derek will be locked in a chamber with rotating electric coils creating magnetic fields roughly the strength of Earth's magnetic field. He'll keep his eyes closed in pitch black darkness with no other stimuli for eight minutes to see if his brain detects the changing magnetic field.

Shin Shimojo is a professor in neuroscience and experimental psychology at Caltech. The research team has published a paper investigating whether humans have brain responses to magnetic fields.

The goal is to determine if humans have any brain response to magnetic field changes, moving beyond controversial behavioral studies to look for systematic responses at the neurological level.

• Modified Faraday cage designed to shield outside electrical effects • Contains a nested three-axis coil set that creates uniform magnetic fields in any direction • Does not block Earth's magnetic field, only redirects it slightly • No sound, vision, or tactile stimulation to isolate the magnetic field response

• Birds use magnetic field sense for navigation and homing • Bacteria, bees, salmon, turtles, rats, dogs, whales, and cats all have magnetic compasses • Dogs preferentially orient their bodies north-south when defecating • Dogs can be trained to locate bar magnets better than finding food treats

Magnetite crystals have been found in the brain that closely resemble those of magnetically active bacteria, suggesting a physical basis for magnetic field detection.

Neuroscience colleagues initially said the idea was hard to believe and impossible, while biologists and geophysicists suggested humans should have this ability like other mammals.

• Robin Baker's 1980s studies found significant results when blindfolded students identified their direction after convoluted drives • Princeton University could not replicate these behavioral results • This contradiction made the need for systematic neurological investigation clear

• Soundproof chamber designed to eliminate external sensory distractions • Contains a reclining chair for comfort during the experiment • Modified Faraday cage that shields electrical effects while allowing Earth's magnetic field through • Completely dark interior with no visual or auditory stimulation

Four square coils in three axes create uniform magnetic fields in any direction. The field can be smoothly redirected to simulate how a person might experience changes while moving in Earth's magnetic field without vestibular system contamination.

A cap with 64 electrodes measures electrical activity of the brain. The electrodes detect alpha waves, which occur around 10 Hertz when awake with eyes closed and indicate relaxation.

• Clockwise magnetic field rotations • Counterclockwise magnetic field rotations • Fixed magnetic field (no change) as a control condition • Each stimulus lasts approximately three seconds

• Dominant signal when awake with eyes closed • Occur at approximately 10 Hertz in most people • Indicate relaxation and sometimes drowsiness without sleep • Suppressed when brain detects sensory signals

Alpha wave suppression is measured as the signature of the brain detecting a sensory signal and moving attention toward it. When alpha amplitude drops, it indicates the brain has perceived something.

Determine if magnetic field rotation causes the amplitude of alpha waves to decrease, which would show that the brain is detecting the magnetic field stimulus.

The researchers are tapping into very subtle brain responses at the subliminal subconscious level, which requires eliminating all other sensory modalities and distractions.

One particularly sensitive subject showed a clear decrease in alpha power of at least three decibels after counterclockwise magnetic rotation, corresponding to approximately 50% reduction in alpha power.

• Counterclockwise rotation showed reduced but not pronounced alpha power response • Clockwise rotations showed clearer alpha power reduction over time • Results indicate he was moderately sensitive to magnetic fields, neither most nor least sensitive

The human brain has the ability to sense magnetic field changes, but this sense is implicit and subliminal, occurring at the non-conscious level of brain processing.

• This is the first step proving magnetic field sensing is not theoretically impossible in humans • Opens the possibility that ancestors may have utilized this ability for navigation • Sets foundation for future research on bringing this ability to consciousness and strengthening it

A surprising number of human languages lack terms like front, back, left, and right, instead using cardinal directions: North, South, East, and West. Native speakers refer to nearby objects using these cardinal directions rather than relative positions.

Individuals raised from early age in linguistic and social frameworks using cardinal reference cues may have developed associative links between geomagnetic sensory cues and daily life, potentially making them consciously aware of their magnetoreception.

People from cultures using cardinal directions would be very interesting to test to see if they can consciously utilize magnetoreception, unlike modern Western populations.

• The sense may be a non-functional relic from ancestors • Modern humans may not need magnetic navigation with technology available • Exposure to artificially created strong magnetic fields from airplanes, headphones, and MRI scanners might have impaired the ability

• Magnetic fields do not have special influence on human health • They do not cure disease or make people smarter • Telepathic communication through magnetic fields is not supported • The study rejects speculative ideas about magnetic field medical applications

The human brain and body can pick up on the physical stimulus of Earth's magnetic field at a neurological level, as demonstrated by alpha wave suppression in response to magnetic field rotation.

This finding is the foundation for future research because conscious behavior cannot occur without underlying neural activity in the brain.

Discovering that humans have magnetoreception ability, even at an implicit level, opens new avenues for understanding human neuroscience and potential navigation capabilities.