Ever had the creepy feeling someone was staring at you, only to turn around and discover it was true? Is it possible to ‘feel’ someone watching you?

Feel like someone might be watching you? Image credit: Seth Showalter via Tookapic

I see you

They say the eyes are the windows to the soul: eye contact is one of the most powerful forms of human communication. Unlike all other primates, human eyes make it extremely obvious which direction we are looking: the exposed white area around the coloured iris gives it away, even from a distance. In most other animals, the iris takes up almost all of the eye, or the area around the iris is darker. Either way, it’s very hard to tell which direction animal eyes are looking, which probably evolved as a way for predators to hide the direction of their gaze from potential prey.

From their very first days, babies prefer faces looking directly at them. And from an early age, our brains respond more to a face looking directly into our eyes than one looking away. We have a ‘gaze detection’ system – a network of nerves in our brains sensitive to whether someone is looking right at us, or just past us. Researchers suggest we have evolved to be so tuned into the direct gaze of other people because it forms the basis of human cooperation and social behaviour.

Sixth sense?

But what about the feeling of being watched? According to surveys, up to 94% of people report having experienced the feeling of being stared at, only to look up and discover it was true. If you’ve had the experience, you’ll know it can feel like ESP or a sixth sense. The phenomenon has also been the subject of plenty of research – the earliest paper I could find on the topic was published in 1898!

Early studies dismissed the idea, declaring that the feeling of being watched was simply a result of being nervous about what may be going on behind your back. There are also other straightforward possible explanations. It could be that in your peripheral vision, you’ve noticed the tell-tale signs of someone looking in your direction. We are enormously sensitive to body language. If someone’s body is facing away from us, but their head points towards us, it’s an immediate give–away they may be looking at us. At the very least, it makes us look up to get more information.

It may also be a self-fulfilling prophecy: if you’re nervous someone is watching you, you may start fidgeting. Your movement alone will make it more likely someone will indeed look at you. There’s also the possibility that as you sit on the train feeling like you’re being watched, the very act of you looking up from your phone makes the person opposite you look up too. When your eyes meet, you wrongly assume this person has been looking at you all along. Research has shown we are hard-wired to assume other people are looking at us, even if they’re not. The argument goes we evolved to think this way because it keeps us alert to danger and ready to interact.

But there’s also a far more intriguing possibility: perhaps your brain has detected someone else’s gaze without your eyes seeing a thing.

Your brain is watching

The evidence for this somewhat unnerving idea comes from studies involving people who have lost their visual cortex due to brain injury. The visual cortex is the part of your brain that processes visual information and maps your view of the world.

One fascinating study reported the experiences of a man who is ‘cortically blind’. Although his eyes are fully functional, and send information to the brain, his visual cortex was damaged by two strokes. As a result, he doesn’t have what we think of as sight. But what do our eyes take in beyond what our sight shows us? Quite a lot, as it turns out and it’s called blindsight.

Although this man (known as TN) can’t see, researchers showed him pictures of faces, some looking right at him, some looking away. At the same time, they measured activity in his amygdala – the part of the brain in charge of facial recognition and emotions. Even though TN couldn’t consciously see the pictures and said he couldn’t tell the difference, there was more activity in his amygdala when he was presented with a face looking directly at him. His brain knew when someone was looking right at him, even when he couldn’t consciously see it.

What an extraordinary trick our brains are capable of. As long as a person looking at us is within our field of view, we can sense it, without consciously noticing anything.

Perhaps this explains the creepy feeling of being watched, no supernatural explanation required.

Links and stuff

• Blindsight: seeing without knowing it
• Video of TN navigating a corridor full of obstacles
• The woman with a strange ‘second sight’
• The feeling of being stared at