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Artwork by Rodrigo Miguel Sepulveda Nunes aka Vile.
This list is just the tip of the iceberg of optical illusions that are floating around the online world. Some, such as the white-gold-black-blue dress, which went viral nearly a decade ago, have even taken the internet by storm.
You might vaguely remember something about a dress or have vivid memories of heated discussions about its color, but no matter how involved you were, if you were on the internet back in 2015, you definitely saw it.
#5
Fossavatn, Island. Haukur Sigurdsson.
If you’re wondering, ‘So, what was the color of the dress that broke the internet?’, the answer is… black and blue. To many people’s surprise, the garment, which many swore to be nearly as bright as the sun itself, was actually a shade way darker.
But despite the truth, more people saw it as white and gold, rather than black and blue, according to the poll on Buzzfeed that started this optical illusion craze.
The optical illusion-of-a-dress became so viral, everyone from celebrities to scientists voiced their opinions. In an interview with BBC, one of the latter, Professor of Color Science and Technology at the University of Leeds, Dr. Stephen Westland, suggested that the reason people saw the same dress so differently was the lighting.
“If it hadn't been taken under very strange lighting this probably wouldn't have happened because if you look at the manufacturer's picture, it is indisputably blue and black,” Prof. Westland told the BBC.
However, the professor noted that the way people see colors varies significantly, as does the way we name or interpret what color something is. “It is possible that people could literally be seeing different colors, but it's impossible to know what is in someone's head.”
Dr. Patrick Cavanagh, researcher of visual neuroscience and perception and co-founder of the Vision Sciences Lab at Harvard, noted that the viral dress was arguably one of the things that brought the general public’s attention to optical illusions.
In his paper on illusions, titled ‘Using Illusions to Track the Emergence of Visual Perception’, he noted that the Google search hits for ‘illusions’ went from just six million back in 2006 to a whopping 635 million in 2023. It’s safe to assume that tens, if not hundreds, of millions were the result of the dress going viral.
In the aforementioned paper, Prof. Cavanagh suggested that illusions arise when perception and cognition are in conflict – when there is a difference between what we see and what we think we should see. “This is not a mismatch between perception and what is physically out there; it is a mismatch between perception and what we think should be out there,” he wrote.
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The expert continued to point out that not all conflicts between cognition and perception are illusions, though. “I may have ordered a hamburger at the restaurant, but my vision says I received a hot dog; I saw my chosen card go back in the deck, but the magician just pulled it out of my pocket. In these cases, the conflict arises due to some external agent—human error or human sleight of hand.
“For an illusion, the trickster must be internal, our own brain, so that we cannot attribute the mismatch to anyone else and, more importantly, so we can use the mismatch to better understand the brain or teach about its principles. The illusion also has stability over time, ruling out other, less reliable tricksters such as hallucinations and delusions.”
Prof. Cavanagh noted that sometimes the conflicts between cognition and perception arise because of an external agent, such as a magician, for instance. Discussing how they use illusions in their tricks, magician Alan Hudson pointed out that magicians have been entertaining audiences with them for centuries. “From making objects disappear to reappearing in a different location, magicians have mastered the art of exploiting our perception and cognition with psychological tricks,” he wrote.
Hudson noted that the art of magic is all about making the impossible seem possible. “Magicians often rely on a range of psychological tricks to create their illusions. One popular technique is misdirection, where the magician diverts the audience’s attention away from their secret moves. By using a combination of verbal and nonverbal cues, magicians are able to manipulate our attention and perception.”