5 Tricks You Can Try Right Now to Fool Your Senses
The best way to tell how your senses work is to use them. Go visit the park and approach strangers, your eyes wide open. “I’m testing out my vision!” you’ll say. “Now, hold still. Because next, I test my sense of smell!”
But there’s another way to uncover some more surprising facts about your senses’ inner workings. You just have to systematically go to each of your senses and break every one of them.
Push Your Eye to Flip Your Vision
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When light enters your eye, rays pass through a lens and end up sticking an upside-down image on your retina. You know this, if you’ve ever seen a diagram of the eye before, but this fact still feels weird. There’s no second step in which another organ flips the image the right way again. Your brain simply takes in a signal about that image, it understands that reality is the inversion of that, and you perceive the world accordingly.
One reason it’s so hard to come to terms with this setup is that there’s seemingly no way to prove it without getting out a scalpel. But actually, you can demonstrate it right now. You just have to be very careful because if you do it the wrong way, you may poke your eye out or even die. In fact, we can’t recommend you try this at all, so consider the following a description of what someone might do rather than instructions for what you should do.
You place a finger on the right corner of the lower eyelid of your left eye. That’s the corner close to your nose. Gently press it. “Gently” is the key word here — pressing too hard will drive your finger through your eye, into your brain and even through your rear skull, which is why you must only press very gently. A black spot will now obscure one corner of your vision, because you have temporarily disabled some rods in your retina.
But the black spot won’t appear in the lower-right corner of that eye’s field of vision. It will appear in the upper-left corner. That’s because your lower-right retina is getting light from the upper-left corner of the world, so your brain is now telling you that the upper-left is what has blacked out.
Voilà! You’ve now proven something scientists in the past could only prove by sticking a physical screen in the dissected eye of a dead yak.
Freeze Time Through Your Ears
For the following trick, you will need to yawn. That won’t be hard. Just thinking about yawning, or reading about yawning, may well make you yawn involuntarily. If that doesn’t do the job, go read one of our more boring articles, such as this one about socks.
You’ll also need to listen to music. If you don’t have a song queued up already, you can listen to this Blondie song being covered by a clown:
During your yawn, it will seem as though the song has briefly slowed down. This is a phenomenon called auditory chronostasis and illustrates how perception of time is always subjective.
The most famous way chronostasis plays out is when you spin your eyes to look at a clock and notice its hands moving more slowly than they actually do. Auditory chronostasis is the less-known aural counterpart to that.
Another way to demonstrate this is to listen to sounds entering each ear in turn. When you have to shift focus from one ear to the other, you will underestimate the length of the pause between the tones because your shift in concentration has changed the pace at which your brain moves forward in time.
Wine Shuts Down Your Nose
This next trick might be the toughest to pull off, because you will need a bottle of wine that smells bad. We know — most of our readers stock only the finest wines, but if you go through your entire collection, you might be able to find one that fits the bill.
Wine that has been corked will sometimes take on a gross musty scent, a condition that is hilariously known as cork taint. Wine scientists have spent centuries trying to figure out cork taint. In theory, cork is a fine substance, providing just the right balance of sealing the bottle off and allowing a tiny bit of airflow, and there’s no obvious reason that the cork should ever rot and smell musty when stored properly.
The bad smell is caused by a compound called 2,4,6-trichloroanisol (TCA). Surprisingly, however, TCA doesn’t actually smell bad. TCA doesn’t smell of anything. This chemical shuts down the channels in your body that take in molecules and create sensations of scent, and in the absence of any scent stimulus, your brain concludes, “Okay, let’s say this smells musty then.”
This may also explain various other times that something smells “off” without you smelling actual putrescence. The issue is that your nose shuts down, and your brain assumes the worst.
Taste Your Own Feet
Go get some cloves of garlic. We know you have some in your kitchen, even if you don’t have any wine — and if you don’t, you have problems far greater than anything in this article, problems that can only be solved by buying some garlic.
Rub those peeled cloves against the sole of one of your feet. Now, wash your hands (this won’t fully remove the garlic scent from them, but we want to limit your hands’ influence on the next part of the experiment). You can also put on socks and shoes now if you wish. In around half an hour, you will taste garlic in your mouth.
It’s not because garlic particles floated up and passed through your lips. Its because those garlic particles (specifically a compound called allicin) entered your bloodstream through your soles and traveled through your body and reached your mouth from the inside.
Oh, and if you’re wondering how you were able to taste garlic this way when taste buds are only capable of tasting sweet, sour, salty and bitter, that answer’s simple: Taste buds are capable of tasting far more than those. You always suspected as much, and when people insisted that all specific flavors are detected by the nose and not the mouth, you should have realized they were lying.
Scratching Turns Off Your Itch Receptors
Itching can be a useful sensation, and scratching can be a useful response. If an tsetse fly is crawling on your arm and preparing to bite, you might sense its presence as an itch, and scratching the area will chase the fly away.
On the other hand, when the itch is a symptom of something that’s no longer an imminent threat (a bite from a now-gone fly perhaps, or a rash), it’s useless. Scratching is also useless at treating the issue. So, why does scratching relieve the itch, given that it doesn’t cure the itch’s cause?
It turns out that your skin has specialized nerves called pruriceptors that sense itching. The very concept of a “sense of touch” is misleading, as it’s a blanket term for a series of very different senses all felt by skin — contact, pain, pressure, heat and more. When you scratch, you often don’t remove the stimulus behind the itch. But you stimulate your pain and touch receptors, and this new information overwhelms the brain and tells it to ignore the pruriceptors’ signals.
That relief doesn’t last. The sensations of pain and touch subside, and you sense the itch again. Stupid nerves. Well, you’re going to show them. You’re going to scratch ever harder now.
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