Tricking your sense of perception is more common than you think

Do you remember the whole dress debate that set the world on fire in 2015?

Is it black and blue, or white and gold?

Well, it turned out basically that the lighting was really bad on this image, which led people to see it one of two ways.

basically the two ways people’s eyes saw it.

I had long known that our perceptions are fallible, but luckily for me, my eyes saw this dress correctly from the jump (it’s blue and black).

More recently I heard of another colour based quiz along the same lines of the dress:

Are these sneakers pink and white, or grey and turqouise?

Once again, bad lighting was the culprit. The sneakers are actually pink with white accents. The lighting is just really bad.

Last week, “Yanni vs Laurel”, aka the audio version of the dress debate, took the internet by storm.

I listened to that original clip, and I heard very distinctly a “laurel” and not even the faintest hint of a yanni. Well, as I kept digging (because honestly this kind of stuff fascinates me), I quickly found pitch-adjusted versions of the clip.

And wouldn’t you know it, when I listened to the down-pitched version, oh how that Yanni reverberated through my skull. I even found one clip where I could hear both at the same time. It was bizarre.

It turns out, the original clip actually IS saying laurel, but as the article linked above points out, the waveform and spectrograph for both names are extremely similar. It’s all about the pitch.

On a similar note, I also recently watched an episode of Smarter Every Day about talking backwards.

In order to “talk backwards”, you can’t just literally flip a word around and pronounce it the same way, you actually have to reverse engineer the sounds.

For example, if you flip “word” around, you get “drow”, and you’d be inclined to pronounce that either “der-ow”, or “der-oh”, but if you stop and think about it, “word” is pronounced more like “werd” not “woh-rd”, so if you say der-ow or der-oh and recorded it, and then played it back in reverse, it would not sound at all the same.

When you make a hard sound like a “d” (known as a “plosive”), you’re releasing a lot of air in a short burst, and it’s not really possible to reverse that (ie sucking a bunch of air back in suddenly). But there are tricks and ways around that, which the video gets into somewhat.

But basically, what you’re doing when you talk backwards, is tricking people’s ears. You have to recreate and simulate sounds close enough to what we’re familiar with to have them get properly interpreted.

It reminds me of how when you’re learning a foreign language, at first it’s all just this seemingly random sounds that don’t mean anything to us. Even if we never learn a second language, we do learn to recognize at least that someone is speaking a certain language by the accent, even if we can’t understand any of the words. For instance, if someone plays you a clip of someone speaking, you’d probably easily be able to tell if they were speaking Russian or German or Japanese even if you couldn’t understand a word of it.

But if you do start learning another language, slowly you start to attach meaning to the sounds (and combinations of sounds that make up words) and it becomes less random noise and more interpretable auditory information.

This is kind of also how babies learn to speak, they don’t initially have the fine motor control of their mouths to be able to perfectly mimic the sounds they hear, but instead they mimic a very basic facsimile (such as “da-da”) and refine it over time.

Anyways, I digress on that.

Now that we’ve seen some really good examples of tricking your visual perception, and also your auditory perception, I’m really curious if examples exist for all 5 of the primary senses.

As far as taste goes, I know of at least two examples — cilantro and marmite. 4–14% of people apparently taste cilantro as more of a soapy taste, rather than a tasty accent for your meal thanks to one specific gene. The same is also true of marmite.

Though that’s not a matter of your sense of taste being fooled, that’s actually hard wired into you. So is something like colorblindness. And there are lots of other cool peculiarities baked into each of us, many that we may never even realize.

So what’s left? Smell, and Touch.

A quick googling for “tactile illusions” yields this wikipedia article that lists a few.

Smell wise (aka olfactory illusions) seem to be rarer, or not well documented.

One thing you might not know is that if you smell gas (when there’s a gas leak), you’re not actually smelling the gas, you’re smelling a chemical that was added to the gas to make it so you can tell when it’s around you. This is both because it’s toxic so you don’t want to breathe too much of it in, and because it’s flammable so you don’t want to spark anything and blow yourself up.

This is common for gases like propane (which is often used for cooking), usually the smell added is that of rotten eggs, because it elicits a strong response from humans, we want to get away from it or at the very least, cover our mouth/nose.

That’s not so much a case of tricking our olfactory senses either though, as just a smart safety precaution. Somewhat akin to having an illuminated red “EXIT” sign so that if there ends up being an emergency, it’s easier for the people around to respond appropriately and quickly.

Now of course it’s not necessarily a bad thing to perceive something differently than other people, if we all perceived things exactly the same I imagine art would be a lot more homogenous and boring. If someone perceived differently than you, that’s a potential learning opportunity — for both.

I hope you learned something by reading this article!

So, until the next example of the dress, or Yanni vs Laurel springs up, stay frosty folx!