What’s Its Like To Have Prosopagnosia Or Face-Blindness? (Medicine)

If you saw the same cashier at the grocery store today as you did yesterday, would you know? What about your boss? Would you recognize them if you saw them outside of the office? What about your mother? Prosopagnosia, more commonly known as face blindness, could make every one of these situations impossible. People with the condition have either some trouble or a total inability to recognize faces—and you could have symptoms without even realizing it.

Imagine you recently visited a pine forest. If you later saw a picture of a pine tree, would you know whether it was a tree you had encountered before? Most of us wouldn’t, since all trees of a given species look basically the same. This is a common way to describe the experience of prosopagnosia. People with this condition generally can’t tell one face from another; for them, walking through a crowd of people is like walking through a forest.

Prosopagnosia happens on a spectrum, with some people only having trouble differentiating between the faces of strangers and others having a complete inability to know whether what they see is a face or an inanimate object. It has been tricky for researchers to pin down exactly what portion of the population experiences face blindness, but it’s estimated at 2 percent, or roughly millions of people. Many of these people may not even know they have it.


The majority of face-blindness cases are what’s known as acquired prosopagnosia, since it forms from brain damage due to things like head trauma, stroke, or neurodegenerative disease. The rest of cases are so-called developmental prosopagnosia, and in these cases the condition occurred before the person developed normal facial recognition abilities, the way most people do by the time they’re teenagers. It could be, however, that acquired prosopagnosia only makes up the majority of cases because it’s very easy to tell a difference between the way you recognized faces before and after brain damage. Developmental prosopagnosia could be more prevalent than we think because many who have it don’t know it—faces have always been a struggle for them and the rest of the world never really talks about how much they rely on facial recognition, so it could be easy to assume everyone shares in their struggle.

Of course, everyone has trouble recognizing people from time to time. Prosopagnosia is more severe than that. According to faceblind.org, “One of the telltale signs of prosopagnosia is great reliance on non-facial information such as hair, gait, clothing, voice, and other information. Prosopagnosics also sometimes have difficulty imagining the facial appearance of acquaintances. One of the most common complaints of prosopagnosics is that they have trouble following the plot of television shows and movies, because they cannot keep track of the identity of the characters.” You can take a test to see if you have prosopagnosia here.

Visual Agnosia Is Why One Man Mistook His Wife For A Hat (Neuroscience)

We’ve told you about prosopagnosia, or face blindness, which is a condition that’s pretty difficult to live with. But the inability to tell people’s faces apart is a walk in the park compared to visual agnosia. Imagine having perfectly clear vision, but not being able to tell if you were looking at the person that you married or an article of clothing. Meet the man depicted in Oliver Sacks’s famous book, “The Man Who Mistook His Wife For A Hat.”

“About six inches in length. A convoluted red form with a linear green attachment … [It’s] not easy to say [what it is]. It lacks the simple symmetry of the Platonic solids, although it may have a higher symmetry of its own.” This is Dr. P, whom neurologist Dr. Oliver Sacks diagnosed with visual agnosia, attempting to describe … something. Do you have any idea what it is? Neither did he — until he took a sniff. “Beautiful!” he said, finally. “An early rose. What a heavenly smell!”

The thing about Dr. P and other people with visual agnosia is that they can see perfectly fine. They just can’t put what they’re seeing together into a coherent picture. That’s why Dr. P had no problem identifying geometric shapes, or describing the individual parts of a rose, but couldn’t identify how those parts added up to a beautiful flower.

That’s frustrating if you’re trying to buy Dr. P a romantic bouquet, or if you’re waiting for him to find his glove (which until he got it on, he described as “a continuous surface infolded on itself. It appears to have five outpouchings, if this is the word.”) But imagine if you’re his wife. There’s a pretty good chance he won’t recognize you at all. He might not even realize you’re a human being.

In the book’s titular incident, Dr. P attempted to lift his own wife’s head from her shoulders, believing that she was the hat that he had worn to his appointment. In Dr. Sacks’ words, “His wife looked as if she was used to such things.” We understand why she insisted he go in to see the doctor.

This isn’t the same thing as face blindness. People with that condition can recognize that something is a face, they just have a hard time telling faces apart.

Visual agnosia is the strongest expression of agnosia, an umbrella term for the inability to process sensory information. A person with this condition experiences the entire world in little bits and pieces and has to put them together on their own. If one of those pieces is particularly prominent, they might have an easier time doing so — you just need to see the chin to know you’re talking to Bruce Campbell.

But sometimes even recognizing one prominent feature can lead you far astray. In one experiment, Dr. Sacks showed Dr. P a photograph of the Sahara desert. There’s no way to know what, but something in the barren picture made Dr. P think of a river. From there, he began to “see” many other things — people dining on the river bank, expansive terraces, and even colorful parasols. It shows the danger of jumping to conclusions, but somebody with this condition doesn’t have many other options.

5 Of The Most Amazing Cases In Neuroscience History (Neuroscience)

The human brain is amazing. It can memorize a deck of cards, use echolocation to get around, and learn to identify musical notes just by hearing them. But for every story of a brain performing at its best, there’s an equally unbelievable story of a brain that just won’t follow the rules. From the archives of psychology, here are five times human brains behaved in unbelievable ways.


In the 1988 film “Rain Man,” Dustin Hoffman plays an autistic savant with an extraordinary memory. That character was inspired by a real man: Kim Peek, a “megasavant” who was estimated to retain 98 percent of everything he ever learned. Although he was born with severe brain abnormalities — not autism, as Hoffman’s character was — that made reasoning and physical coordination challenging, he had a superhuman ability to take in and retain information.

He could read two pages of a book at once and remember everything he read so that by the time he died in 2009, he had read as many as 12,000 books. How? Experts believe it may have been because he was missing his corpus callosum, the nerve tissue that connects the brain’s two hemispheres. Despite the fact that this made it difficult for Peek to brush his teeth or dress himself on his own, it may have led to a rewiring that helped each hemisphere gain other functions that it never would have if the two were connected.


Imagine if every face you saw morphed into the face of a dragon. That’s what this woman had experienced for her entire life. “She could perceive and recognize actual faces, but after several minutes they turned black, grew long, pointy ears and a protruding snout, and displayed a reptiloid skin and huge eyes in bright yellow, green, blue, or red,” write the authors of a 2014 Lancet paper about the phenomenon, which they called “prosopometamorphopsia.” Even worse, she regularly experienced hallucinations of similar faces coming toward her from the walls, electric sockets, and computer screens. It wasn’t until she was a teenager that she realized that most people don’t see faces this way. At 52, after decades struggling with depression and an inability to keep a steady job, she sought help from a neurologist, who put her on an Alzheimer’s drug that kept the symptoms at bay. At the time of the Lancet paper, she had kept the same job for the past three years.


If this one sounds familiar, it’s because it’s the title for neurologist Oliver Sacks’s famous compilation of clinical case studies. The titular tale is about a patient Sacks referred to as Dr. P, who had a condition known as visual agnosia. That meant that he could see just fine, and his other senses were intact as well, but he had a problem putting the details of what he was seeing into a coherent picture.

When given an object to identify, he’d say things like “a continuous surface infolded on itself. It appears to have five outpouchings, if this is the word,” to describe a glove, and “A convoluted red form with a linear green attachment,” to describe a rose. And yes, he did mistake his wife for a hat: Sacks recounted a moment when Dr. P was getting up to leave and attempted to lift his wife’s head off of her shoulders, believing that it was his hat. Luckily, his wife was used to such things.


In the 1870s, French-Canadian lumberjacks working in a forest in Northern Maine began to behave erratically. When they were startled, they’d jump, curse, yell, lash out, or even imitate the speech or actions of people around them. Sometimes, they’d mindlessly follow commands. All of it appeared to be involuntary, and only in response to a surprise or startle. To this day, no one is sure whether this condition was caused by problems in the nervous system or a psychological disorder, but these men were just some of the patients who have suffered from this “startle syndrome”; isolated populations throughout the world, including the “Ragin’ Cajuns” of Louisiana and the latah of Indonesia, exhibit similar symptoms.


This patient of famed neurologist Paul Broca was named Louis Victor Leborgne, but most people just called him Tan. That’s because he had a neurological condition that made him unable to speak, except to utter one word: “tan.” It’s not that he couldn’t communicate — that one syllable came with plenty of expressive hand gestures, not to mention variations in pitch and inflection.

He even appeared to understand everything that was said to him and responded as best he could. He was referred to Broca in April 1861 and died just a few days later, but the biopsy of his brain would change neuroscience forever. He had a lesion in the left frontal cortex — a region now known as Broca’s area, the center of language function in the brain. Today, Leborgne’s condition is known as Broca’s aphasia.

We May Finally Know How The Pyramids Were Built (Amazing Places)

It’s easy to see why people are so fascinated with the Egyptian pyramids. There are a lot of mysteries surrounding their construction. You probably don’t believe the conspiracy theories that say they were built by aliens, but they weren’t built by slave labor, either. So how did people 4,000 years ago create some of the largest, most iconic structures on Earth? We’re still not totally sure — but a new discovery could make it a whole lot clearer.

The oldest of the most famous pyramids in the world is also the largest. At 481 feet (146.5 meters) tall, it’s not called the Great Pyramid of Giza for nothing. It was constructed at the order of Pharoah Khufu sometime around 2560 B.C.E., although how it was actually constructed has been shrouded by history. Still, bit by bit, archaeologists have been able to explain various mechanisms behind the building’s construction. The stones themselves were mined from a quarry just south of the pyramid, and researchers believe that their journey across the desert was made easier by wetting the sand first. But that only explains how the stones got from one location to another, not how they were then lifted high into the air and deposited in an enormous triangle.

Researchers believed that action would have involved a ramp of some sort, and that’s a pretty fair guess. It’s not as if they had a five-story crane. But as for the actual evidence of such a ramp? Researches were coming up empty-handed. It’s a particular challenge because the ramp would have needed to be very steep — an incline of about 20 degrees or so — and that would have posed a significant challenge for a 2.5 ton stone. Now, a new discovery at a different quarry might shed light on how ancient people managed such a feat.

At Hatnub, another rock quarry located in Egypt’s eastern desert, an Anglo-French team found a very unusual ramp carved into the ground that hinted at some surprisingly advanced technological achievements. For one thing, it was pretty steep, but more significantly, it was flanked on both sides by staircases. These stairs were marked with recurring holes that could have contained wooden posts (which would have rotted away long ago). According to the mission’s co-director Yannis Gourdon, “This kind of system has never been discovered anywhere else.” What’s more, it’s dated to about 4,500 years ago, well before construction began on Khufu’s big legacy.

Roland Enmarch, another scholar who participated in the expedition, noted that the patterns of the post holes in the stairs suggested a particular kind of rope-and-pulley system. Similar pulley systems are well-documented in Greek technology, but this discovery predates those devices by some 2,000 years. Since this specific ramp is cut into the rock itself, it wouldn’t have been used to build the actual Great Pyramid. But it does suggest that the ancient Egyptians had a firm grasp on the kinds of simple machines that can be used to turn an impossible amount of hard work into just a whole lot of hard work.

Things That Game Of Thrones Can Teach Us About Science (Science)

It might be called “fantasy” for a reason, but it turns out that even some of the most magical elements of “Game of Thrones” — the super-popular book series that became a super-popular HBO series — has some roots in science. Even better, knowing how can teach us even more about how real-world science works. Here are five lessons you can learn about real science from the fantasy world of the Seven Kingdoms.


Wildfire is such a terrifying weapon that it’s no wonder that, according to Game of Thrones lore, its recipe is a closely guarded secret. It’s described as a volatile green liquid that catches fire easily and burns until its fuel is exhausted. It can ignite any material and will even continue to burn while floating on water.

It turns out that there have been real-life versions of something akin to wildfire throughout history. Most mysterious is probably Greek Fire, a liquid that seventh-century Eastern Roman armies would spray on enemy ships, where it would burst into flames on contact. Though no one is sure what it was made of, rumors have included everything from sulfur and liquid petroleum to quicklime, bitumen, and burning pitch. Centuries later, the sticky, long-burning liquid weapon known as napalm hit the scene, and its horrific destruction when in the hands American forces during the Vietnam war led to its outlaw (at least for its use against civilians) in 1980.

Of course, neither of those substances are green, and both burn with a boring orange flame. But it really is possible to make a liquid that burns with a green flame that ignites whatever it touches. Last month, Youtubers Nick Uhas and Trace Dominguez made their own version of wildfire with boric acid powder, methanol, and — what else? — glowsticks. The results were pretty jaw-dropping:

We Made REAL Game of Thrones Wild Fire! | Nickipedia


While most characters in Game of Thrones speak English, a few cultures speak languages wholly invented for the series. The nomadic horse warriors known as the Dothraki speak one such language, which (along with the Valyrian language) George R.R. Martin made up for the few phrases he included in the book series. But for the TV show, the producers needed more than just a few lines of these foreign tongues — and that’s why they turned to linguist David J. Peterson.

Languages like Dothraki and Valyrian are what’s known as constructed languages or “conlangs,” and Peterson is an expert conlanger who’s constructed languages for a number of shows on television. The brilliance of a language constructed by a professional linguist is that it uses the rules of linguistics, so understanding how Peterson constructed Dothraki or Valyrian can tell you more about how your own language works. Luckily, Peterson explained just that in a 2015 op-ed for the LA Times.


Of all of the fantasies that fill Game of Thrones, The Wall might be the most outlandish (and that’s saying something). The Wall is a 700-foot (200-meter) tall, 300-mile (500-kilometer) long fortification that divides the realm of the Seven Kingdoms from the no man’s land further north. Normally, to build something this tall requires a hollow steel skeleton, deep piles (aka stakes that keep it planted to the ground), and, oh yeah, an incredibly tall crane. Although there have been cultures who achieved such a feat without modern technology — the ancient Egyptians likely combined a ramp with a rope and pulley system to pile the bricks of the pyramids — no one past or present has ever done such a thing with ice. Trace Dominguez gets into the hypothetical challenges involved with building this monstrosity in the video below.

Could We Actually Build The Wall from Game of Thrones?


Hodor, a “simple-minded” servant of House Stark, was actually born with a different name, but people began calling him “Hodor” because that’s the only word he can say. It’s not that he can’t communicate — he’ll utter this word with varying emphasis — it’s just that he can’t actually use other words. The show eventually explains why, but there’s a real-life explanation as well: If Hodor existed in the real world, he’d likely be suffering from Broca’s aphasia. This condition is caused by a lesion in the language-centric region of the brain known as Broca’s area, and the first patient documented with the condition could also utter only one word. His name was Louis Victor Borges, but just like Hodor, people called him by the only word he could say: “Tan.”


Even if you’re not a Game of Thrones fan, you’ve no doubt heard the phrase “Winter is coming.” That’s uttered time and time again in the earlier seasons of the show because the story is set in a world that has long, unpredictable seasons — which means that winter could come at any time and last for years. George R.R. Martin has specifically addressed his fans’ desire to come up with a scientific explanation for the seasons: “I have to say, ‘Nice try, guys, but you’re thinking in the wrong direction.’ This is a fantasy series. I am going to explain it all eventually, but it’s going to be a fantasy explanation.”

Fantasy explanations aside, a number of scientists have weighed in on this with some pretty persuasive scientific explanations. For example, a planet’s seasons come from a tilt in its axis. The more tilted it is, the longer the seasons, which is why Uranus’s 98-degree tilt gives it 42 years of winter. It’s possible that the Game of Thrones planet has seasons of an unpredictable length because it has a “wobbly” axis that shifts its angle throughout its orbit. The strange seasons could also come down to a complicated Milankovitch cycle, the combination of quirks in orbit, axial tilt, and precession (the change in direction of the axis) that create their own change in weather and season.

The explanation could also just come down to climate science: Maybe the volcanoes of the Valyrian peninsula erupt every so often, filling the atmosphere with clouds of sulphuric acid that block out sunshine and create something akin to winter. While none of these explanations will ever come out in the show, they at least help us learn more about science in the real world.

Movie-goers Blink In Sync For An Eerie Reason (Psychology)

You blink 15–20 times per minute. If you watch a 150-minute movie, that translates to about 15 minutes worth of screen time. That’s a lot of Middle Earth to miss! (No wonder the Eye of Sauron never blinks.) Don’t worry though: Studies suggest that our brains have figured out a way to compensate.

For every few tenths of a second it takes to blink, there’s a gap in information that your brain has to fill in. Add that up to the amount of movie plot missed, and it’s a wonder we can keep the storyline straight. For a 2009 study published in the Proceedings of the Royal Society B, University of Tokyo researchers led by Tamani Nakano sought to figure out how moviegoers are able to fully understand a film when they lose about 15 minutes blinking. The researchers divided study participants into groups and played them clips from either a silent comedy, an aquarium film with no narrative, or an audiobook.

The results showed that the group watching the silent comedy blinked in near-unison about 30 percent of the time. The aquarium and audiobook groups had no such synchronized blinking. The researchers suspect that this was likely not a coincidence because the synchronized blinks happened during “non-critical” parts of the film, such as after action sequences or when the main character couldn’t be seen.

“We all commonly find implicit breaks for blinking while viewing a video story,” Nakano says. It just so happens that those breaks are surprisingly similar from person to person.

A few years later, Nakano hit upon why: When people blink during a film, they momentarily decrease activity in the attention-centric parts of their brains but increase activity in the default mode network. That’s the part that turns on when you stop paying attention and let your mind wander. “The results suggest that eyeblinks are actively involved in the process of attentional disengagement,” Nakano and his team concluded.

Movies aren’t the only time our brains find the perfect places to blink. Nakano has also found that blinks sync up during conversation, for instance. And in 2016, Nakano teamed up with psychologist and magician Richard Wiseman for a study they published in the journal PeerJ, which showed that people also synchronized their blinks when watching a magic trick. According to the study, those blinks happened most often “after a seemingly impossible feat, and often coincided with actions that the magician wanted to conceal from the audience.” Sounds pretty convenient to us.

The Rich Are Less Empathetic Than The Poor (Psychology)

Forget men coming from Mars and women coming from Venus — when it comes to life experiences, it can seem like the rich and the poor are from completely different solar systems. According to research, this isn’t in your imagination: your empathy for others changes with your social class.

Arizona State University neuroscientist Michael Varnum has studied this idea quite a bit. For a 2015 study published in the journal Culture and Brain, he and his team asked 58 participants questions designed to determine their social class, including those about their parents’ education, their income, and their perception of their own social status. They also asked participants to fill out a questionnaire that measured how empathetic they believed themselves to be. Then, participants each donned an EEG cap designed to measure their brain waves and looked at a series of pained and neutral faces.

Although those of higher socioeconomic status rated themselves as more empathetic — a finding that inspired Varnum to author a whole new study on the phenomenon — the EEG didn’t lie. It showed that the higher the subject’s status, the less their brain reacted to the pained expressions. According to the study, “these findings suggest that empathy, at least some early component of it, is reduced among those who are higher in status.”

Varnum published another study in 2016 that honed in on socioeconomic differences with mirror neurons, the neurons that seem to simulate the actions of others. It found something similar: those of lower socioeconomic status have more activity in their mirror neurons when watching people perform a task. Yet another study out of New York University found that when walking around a city block, higher-class people have a shorter “social gaze” — that is, the amount of time they look at the people around them.

Why would the well-to-do have less empathy for others than the poor? According to The Science Of Us, “It may be that growing up poorer means that you have to rely on others more; it may also mean that you live in a less-secure environment, so you need to attend to others to keep yourself safe.”

In the same way, money affords a certain amount of privacy and independence. Those without it spend more time riding on public transit, standing in line for necessities, and doing other things that put them in the presence of other people. A life spent around others requires good skills in social interaction.

On the flipside, Steve Siebold, a self-made millionaire and the author of “How Rich People Think”, considers this lack of external focus a virtue. “The rich go out there and try to make themselves happy. They don’t try to pretend to save the world,” he told Business Insider. “If you’re not taking care of you, you’re not in a position to help anyone else. You can’t give what you don’t have.”

We Probably Use Online Reviews Wrong (Psychology)

You’re on a road trip and getting hungry, so you decide to check restaurant reviews for the next town you’ll drive through. Slim pickings: there are only two spots that sound the least bit appetizing. One has two stars with 500 reviews; the other has two stars with only 25 reviews. Which is more likely to be a good experience? We’ll tell you right now: you probably chose wrong. According to research, most people do.

To examine how people use online reviews, researchers from Indiana University Bloomington and University of California, Los Angeles first had to prove what the best way to use them really was. They used a statistical model to find patterns in millions of reviews for products on Amazon. They found that there was no relationship between the number of reviews and the average rating — that is, a product with 5,000 reviews was just as likely to have two stars as to have five stars, and a product with five stars was just as likely to have 5,000 reviews as to have five.

Next, they recruited 132 people to look at pairs of phone cases, presented the way they would on an actual online store. After checking out the average user rating and the total number of reviews, they were asked to select which of each pair they would buy. Across the board, the participants chose the product with more reviews.

What’s wrong with that? The number of reviews isn’t a sign of how good a product is; it’s just an indicator of how accurate the average rating is. Statistically, a two-star product with 5,000 reviews is more likely to be of two-star quality than a two-star product with five reviews. That means that when faced with two low-rated products, you should choose the one with fewer reviews because that rating is more likely to be wrong. It’s no guarantee, but the odds are in its favor.


The problem people get into is judging a product — or restaurant, or hotel — by its popularity, not its rating. But plenty of things that are popular aren’t necessarily good (Smoking! Sleep deprivation! Smooth jazz!). As the motherly adage goes, if all your friends jumped off a bridge, would you? We tend to go along with the pack because of a concept called social proof. If we see all our friends driving Ford Pintos, we feel like we’d be missing out if we didn’t buy a Ford Pinto.

According to the researchers, this study says we all have a lot of learning to do. “Consumers try to use information about other people’s experiences to make good choices, and retailers have an incentive to steer consumers toward products they will be satisfied with,” says lead author Derek Powell of Stanford University. “Our data suggest that retailers might need to rethink how reviews are presented and consumers might need to do more to educate themselves about how to use reviews to guide their choices.”

Asymmetric Insight Is Why You’re Not As Mysterious As You Think You Are (Psychology)

Think about your best friend. How well do you know them? Do you know their favorite things, pet peeves, social tendencies? If they got the wrong order at a restaurant, would they choke it down or send it back? Do you think you could accurately predict how they’d act in any given situation? If they’re a good enough friend, the answer is probably yes. Now turn the tables. How well do they know you? Do you think they could predict your behavior just as easily? According to research, you probably don’t. Most people believe they see much more of other people than people see of them. That illusion is called asymmetric insight.

In 2001, researchers from the University of Illinois and Williams College performed a series of studies looking into how people’s perceptions of others compared to the perceptions they thought others had of them. In one experiment, volunteers were asked to think of a best friend and rate how well they believed they knew the person. The questionnaire included a series of illustrations of an iceberg submerged in gradually greater levels of water. The volunteers were asked to circle the one that represented how much of their friend’s “essential nature” they could see — in other words, how much of your friend’s true self is hidden beneath the surface?

Next, they filled out the same questionnaire a second time, this time indicating how much of themselves their friend could see. As you might guess by now, most people rated their friend’s iceberg as barely submerged but their own as mostly submerged. They believed they knew more about their friend’s true self than their friend knew about them.

In another experiment, volunteers were asked to complete words with missing letters — something like s–r, which could be star, spur, stir, and so on — then say how much they thought their responses said about their true selves. Most people thought it didn’t reveal anything at all. But when they looked at other people’s responses on the same exercise, they were suddenly full of descriptions: they were positive thinkers, they were vain, they loved nature, they were sleep deprived or in a dishonest relationship. One volunteer wrote, “He seems to focus on competition and winning. This person could be an athlete or someone who is very competitive.” And yet another experiment showed the same thing in ideological groups: liberals believe they know more about conservatives than conservatives do about liberals, and vice versa.

Asymmetric insight may sound like a harmless quirk, but it gets dark fast: If you see yourself and your group as nuanced and mysterious, but other individuals and outsiders as open books, it’s harder to take their perspective. You won’t walk a mile in someone’s shoes when you think you already know what their shoes feel like. That leads to conflict and hostility, not reasoned discourse and understanding.

This is just one shade in the rainbow of your own cognitive biases. You also tend to think everybody else thinks like you; that other people’s behavior is because of who they are, not their circumstances; and that ad campaigns only convince other people. Our brains are wired to hold ourselves above all others, and as a result, we’re full of biases that make other people look pretty bad.

But for the world to be a more reasonable place, we’ve all got to fight those tendencies. Luckily, you’ve got the first step covered: You know they exist. All it takes now is to remember that when the next conflict arises.

Eternal in Knowledge, Eternal in Contents..