A few years ago it was "the dress." (Was it blue and black or white and gold?) Now, all of a sudden the internet is up in arms about an audio clip that, depending on whom you ask, either says "laurel" or "yanny."

A lot of people, it seems, are both bored and looking for something to argue about and/or fascinated by the fact that two rational, healthy people can perceive the world in two completely different ways. That includes scientists.

23 studies and counting...

Since #TheDress stormed the internet three years ago, no less than 23 studies have dug into why some people saw it one way and others completely differently, the British Psychological Society Research Digest blog reports. All this effort has produced some real, if technical, insights into the phenomenon. If you saw the dress as white and gold you might have greater "macular pigment optical density" in your eyes, for instance, or your brain may have a tendency to do more "top down" interpretive processing.

But the authors of a recent review of all this research also conclude that a great deal of mystery remains. "The fact is that researchers have failed to come up with a theory that can satisfactorily explain the dichotomic behaviour of the population when viewing said optical illusion," they write. Or, in other words, science still isn't entirely sure what's going on. BPS calls it "a lesson in humility."

... but human brains are still weird and mysterious.

So how about this latest auditory example of the phenomenon of people perceiving the same thing in wildly different ways? Does science have an explanation here? Experts have rushed to offer some, as Wired reports (the article also offers a deep dive into the origins of the meme for the curious. Short version: blame teens).

"The reason that the recording is so contested is likely because it's noisy, meaning there are lots of different frequencies captured. What you hear depends on which frequencies your brain emphasizes," the article sums up. "The higher frequency sounds in the recording make people hear 'Yanny,' whereas the lower frequencies cause others to swear they hear 'Laurel.' What you hear depends on what sounds your brain is paying attention to, your past experiences, and what you're expecting to hear." Differences between headphones and speakers, it adds, are probably adding to the confusion.

While the technical details are different, this explanation actually sounds a great deal like the explanation given for #TheDress. When faced with ambiguous information (e.g. a badly lit garment or a noisy recording) our brain does its best to puzzle out a coherent interpretation based on our prior experience and expectations. As these differ significantly from person to person, so too do their final impressions.

Of course, this latest internet flash frenzy is likely to drive as many new studies as the last one, so science will no doubt have more to say about the details of how our ears and brains process laurel vs. yanny in a few years. But chances are also fairly good all that research will probably come up just as short as all the effort to figure out #TheDress.

Human minds, in other words, are indeliably weird and complex. We don't so much perceive the world, as we construct it. And while science can tease out the factors contributing to how we piece together some particular part of the world, the fundamental strangeness of these experiences (and of other people's brains) is unlikely to be completely eliminated by science.

That means that even what you can plainly see and hear is, to some degree, subjective. As BPS suggests, knowing that should make you at least a little more humble about the certainty of your more complex knowledge and beliefs. 

Published on: May 17, 2018