On August 14th, 2017 we learned about

Higher prices can have a positive effect on our perceptions

Think of the tastiest candy you’ve ever eaten. Think of the wrapper it came in, how it was presented, and importantly, the price you paid for it. It turns out, that candy could have tasted even better if you thought it was worth more money. Brain scans of people assessing wines have found that this preference for higher-prices isn’t just some kind of post-hoc rationalization to justify spending. Higher prices can trigger more activity in the brain’s reward centers, meaning your that candy that you bought for $1.00 would have been even sweeter if you thought it was worth a $1.50.

How to value vino

Candy prices are kind of predictable though, and unless a specialty shop is involved, it’s hard to be convinced that one Milky Way bar is all that different from another. Wine, however, is sold under many labels at varying prices, and so it was a great way to test how much prices influence people’s perception of quality. Volunteers then sipped wine through a tube while their brains were scanned in an fMRI so that their reactions to both fictional prices and real wine could be tracked. Unknown to the participants, the wines were identical in each round of sips, and the prices were randomly assigned, ensuring that the wine’s “actual” value was not the main factor in people’s perceptions.

As people sipped, they generally favored what they thought were the more expensive wines. This was true whether they thought they’d be paying for wine or being given it for free, indicating that a concern over their resources was not what made something tasty. People weren’t making the most of their available resources— they were instead enhancing the flavor of the wine with a price-based placebo effect.

Believing it’s better

Placebos are usually discussed in terms of health treatments, but the same underlying concept applies were. If a person thinks a pill will make them healthy, that can be enough to convince their body to recover. In the context of wine prices, the so-called “placebo marketing effect” was found to trigger physiological differences in people’s brains. Sipping pricier versions of a wine lead to more activity in the medial pre-frontal cortex and the ventral striatum, the former being tied to price-comparisons and the latter being involved in reward and motivation systems. As far as these people’s brains were concerned, pricier wine was honestly better.

There are limits to this, of course. Putting a $100 price tag on vinegar isn’t going to change anyone’s mind. But for wines, or candies, or anything else that we expect to have variable prices and quality, this can make a difference. It’s something to keep in mind when you make up your mind about a food or experience before you’ve tried it— like a four-year-old who doesn’t want to try a vegetable, you really can convince your brain that something you don’t want will be miserable to have in your mouth.

“So which would you rather have, a new kind of chocolate in a plain wrapper or one in a fancy box?”

“Is it a box I could keep?” asked my third-grader, “because if was going to be thrown away I’d take the smaller wrapper to make less trash.”

After many hypotheticals, I did eventually get her to pick the theoretically pricier chocolate over something cheaper, but the exchange felt like another reason this study was done with adults sipping wine.

Source: Why Expensive Wine Appears To Taste Better, Scienmag

On August 10th, 2017 we learned about

For a healthier hippocampus, consider playing more Mario

Is Mario better than Call of Duty? By and large, yes, but beyond the likely enjoyment of playing these games, researchers are finding that that Mario games, or at least the “3D platforming” games like Super Mario 64, may be better for the health of your hippocampus. You want a robust hippocampus for a variety reasons, starting with its role in managing your long-term memory and processing emotional information. As it turns out, exploring complex maps found in these platformers seems to boost the hippocampus, while twitchier action games like Call of Duty or Killzone seem to have the exact opposite effect, reducing the hippocampus in favor of other brain structures.

Learning styles matter

This study started with MRI brain scans of regular gamers, sorted by what kind of game they usually play. Test participants were also asked to navigate a virtual maze to see what kind of learning styles they generally adopted. This stage of testing found a correlation between people who predominantly played high-speed action games and response learning types. In the maze, this meant that these participants were more likely to navigate by memorizing and reproducing patterns of movement, even when those patterns become very repetitive. On the other hand, people who spent more time playing 3D platform games were more likely to be spatial learners, building more of mental map by noting landmarks and spatial relationships.

Researchers then wondered if there was some self-selection going on here. Maybe people who were naturally better at playing out wrote patterns liked the games that rewarded those skills more, and vice versa. To check, a second set of test subjects with less gaming experience were asked to play 90 hours of one type of game or the other, with brain scans being taken before and after to see if any structural changes took place as a result. Indeed, there was a change, but the exact change seemed to depend on just what kind of learner a player was to begin with.

Gameplay that reshapes the brain

Response learners showed a marked reduction in their hippocampus after 90 hours of Call of Duty, but an increase in their caudate nucleus. The caudate nucleus is a separate brain structure that’s associated with reward systems, impulse control processing environmental feedback. Researchers suspect that these action games require very little spatial processing but instead exercise functions found in this second brain structure. That would be fine, except the accompanying loss of gray matter in the hippocampus is slightly concerning, at least for response learners.

Spatial learners may play these first-person shooters very differently, as their brains didn’t show the same shift in resources from the hippocampus to caudate nucleus. Somehow they got a boost in their hippocampus playing both action games and 3D platformers. Response learners’ hippocampi also benefited from some time collecting stars and shines with Mario, making those games the safer option for both player types. So if your memory struggles with complex spatial relationships, Super Mario 64 may help (but the twitch-oriented Super Mario Run probably won’t.)

My third grader asked: What about Minecraft?

While not mentioned in this study, it would seem like the slow pace and sprawling, unmarked world of Minecraft would really give your hippocampus a workout. The paper didn’t list every game they compared, but Call of Duty is somewhat infamous for its linear maps that require very little thought to navigate, and so anything that you can actually get lost in is probably giving the gray matter outside your caudate nucleus a bit more stimulation.

Source: Why ‘Super Mario’ May Be Good for Your Brain, But ‘Call of Duty’ Isn’t by Dave Roos, Seeker

On July 18th, 2017 we learned about

Your brain bestows rewards when you cater to your curiosity

There’s a certain satisfaction in finding the answer to a question. You might call it a spark of excitement, a moment when things click, or even an epiphany, but studies of brain activity would probably call it dopamine. Researchers at the University of California, Davis were looking at the intersection of curiosity and learning, and found that not only does learning about questions that pique your interest help you retain information, but it also gives you the neurological equivalent of a lollipop as further reward for learning about the world.

Rewards and retention

The study started by finding out what volunteers were curious about. From a list around 100 trivia questions, each participant indicated which items they thought were interesting to find out about. Participants then reviewed the same lists, plus found out the answers, while having their brain activity scanned in an fMRI machine. When a question that had previously been indicated as a point of interest was answered, brain activity was punctuated with activity in the brain’s reward centers. Brains treated satisfied curiosity like a taste of candy or the receipt of money, complete with an extra dose of the neurotransmitter dopamine. Learning about these points of interest was a literally a pleasurable experience.

While volunteers were feeling good about learning that the word dinosaur means “terrible lizard,” their brain was doing other work as well. The hippocampus was active while the trivia questions were observed, indicating that participants’ brains were working on new memories. Appropriately, people were able to more easily remember the answers to questions they had been curious about later on compared to trivia that was of less interest. That’s not to say that you have to care about every topic you hope to learn about though, as a second aspect of the experiment found that other learning was taking place at the same time.

Incidental information

Mixed in with the all the questions and answers, random images of faces were also flashed in front of participants, without further explanation. Participants were later asked about those faces, and people who were feeling curious later remembered more of the faces than people who weren’t as engaged. Even though the faces were unrelated to the trivia questions, they were apparently remembered as part of the experience of learning. Researchers compared it to the way that you might remember banal circumstances surrounding an important event, like the food you were eating when you got learned some long-awaited news.

All this indicates that learning about things you’re curious about is much more efficient and enjoyable than topics you don’t care about. Of course, that’s not always an option, even for two-year-olds who won’t stop asking “why?” over and over. The backup may be to couple topics you’re excited about with slightly less interesting stuff, almost like a word problem on your favorite topic in an otherwise difficult math class. Satisfying your curiosity will hopefully be pleasurable enough to write other memories to your brain at the same time.

Source: What’s Going on Inside the Brain Of A Curious Child? by Maanvi Singh, Mind/Shift

On June 28th, 2017 we learned about

Mice map their world by scanning space with their whiskers

You’ve probably never tried to navigate through a dark room by bumping your face into things. At least not on purpose. Instead, you most likely extended your arms slightly, so that your fingertips could gently come in contact with objects as you walked along. With each bump or poke, you not only felt contact in a specific finger, but you also started building a conceptual map of the room. This somewhat clunky process may be just good enough to get you to the bathroom in the middle of the night, but it’s hugely important for an animal like a mouse. So much so that they even do it with their face.

Not every part of a mouse’s face is that useful for crawling through dark nooks and crannies though. Their eye’s aren’t great at focusing on objects close to their head, which means that a lot of information is needed from the mouse’s 24 whiskers along its snout. While lots of mammals rely on whiskers to help sense their local environment, researchers have found that the way mouse brains use that information goes beyond what your average cat or dog will do. Instead of just perceiving contact from a specific whisker, that input also triggers special structures in the mouse’s somatosensory cortex called barrel columns, which go on to start building mental maps of the mouse’s environment.

Sensing touch, as well as empty space

Researchers were able to watch this activity in multiple layers of a living mouse’s brain at once. Brain cells were cultured to be fluorescent when active, revealing a few stages of activity when a mouse brushed by a small stimulus on one side of it’s head. One layer of the cortex seemed to only keep track of which whisker felt something, much like you know which finger touches something when you can’t see it. The other layers took the movement of the whiskers as if they were scanning the space around that stimulus— even the empty space was providing some feedback, beyond the moment of contact. Humans scan spaces to build mental maps too, but most of our input comes from visual information. For a mouse crawling in the dark, the whiskers seem to be the more reliable source of data.

The next step is to see how much detail mice can really get from their scanning whiskers. Can they recognize specific objects? How is that information processed so that further actions, like hiding or pouncing, take place? The complete picture won’t just help with understanding how cool mouse faces are, but also to build a model of this kind of brain activity in all mammals. We know that our hands can do some to the work these whiskers take on, so seeing what a mouse brain “sees” may provide insight on human brain activity too.

Source: A mouse’s view of the world, seen through its whiskers by Robert Sanders, Berkeley News

On June 20th, 2017 we learned about

How Petal Huit could perceive and parse the thoughts of other people

Sciencing the Sisters Eight!

Book six of The Sisters Eight reveals that the anxiety-ridden Petal suddenly has a whole new set of worries in the world, because in addition to her own thoughts, she can now hear what’s happening in other people’s heads as well. The ability manifests very similarly to listening, as Petal needs to concentrate to pick out whichever voice she wants to hear, almost like trying to listen to a friend among the chatter of a crowded room. As with almost everything in her life, Petal isn’t happy about this development, even though eavesdropping on the minds of others ends up saving one of her sisters from danger.

Sharing one’s thoughts… sort of

Reading minds has been a fascinating concept for ages, in no small part to humans being social animals that depend on communicating with each other. Our anatomy has even evolved to better enable communication, and some of us can be quite skilled at reading subtle cues to learn more about a person than they intend to reveal. In some cases, these cues and an inclination for communication have been exploited in a series of techniques known as cold, warm and hot readings. A cold reading involves making general statements, like “You know someone named John” to a large crowd, allowing people to identify themselves as being a match for those statements. Hot readings are even more manipulative, where the supposed psychic is secretly given information about a person, then pretends to read their target’s mind by revealing it later. However, these forms of “mind reading” are more about the tricking an audience, and obviously a nervous seven-year-old like Petal would much rather hide under her bed than impress a large crowd.

Matching and mimicking

A form of mind reading that’s actually being explored by science is based around special brain cells that have been dubbed “mirror neurons.” These neurons have been found to activate when performing an action as well as witnessing someone else perform that same action. This neurological “monkey see, monkey do” concept was once thought to be the key to unlocking human learning on a grand scale, although now expectations are a little more refined. These brain cells probably do play a role in social learning, but they’re not the only influence on how we share information and experiences with each other. As far as Petal is concerned, mirror neurons have generally been tied to experiencing activity rather than inner cognition, and so they’re probably not how she’d listen in on the snarky comments her sister Rebecca might be thinking at any given moment.

Monitoring minds in real time

This doesn’t mean that reading the inner thoughts of another person is impossible though. It’s just that at this point you probably need some very powerful computers and embedded electrodes to do it. Volunteers’ brain activity was monitored while they looked at images of houses, faces or blank squares, and those patterns were analyzed to predict which type of visual a person was viewing at any given moment. With 400 millisecond exposures to each image, the brain activity was consistent enough that the computer algorithms could correctly identify what someone was seeing almost as fast as they could see it. While each of us might experience the world in our own way, it turns out that how our brains initially process stimuli is universal enough to be recognizable from the outside.

This suggests that Petal’s power is similar to this kind of pattern recognition, only with much better resolution and without the need for electrodes. If she’s able to somehow detect the electrical activity in different parts of another person’s brain, she could hypothetically know what that person is looking at. Other studies have found similar consistency in how our brains remember and sort our vocabularies, and the combination of these two types of activity could then be used to “hear” what someone is thinking. It’s always assumed that Petal hides under beds out of fear, but maybe that’s just a good quiet place to tune into other people’s heads.

Source: New Technique Allows Scientists to Read Minds at Nearly the Speed of Thought by George Dvorsky, Gizmodo

On June 18th, 2017 we learned about

How Durinda Huit’s finger-pointing induces intermittent paralysis

Sciencing the Sisters Eight!

In Durinda’s Dangers, it’s revealed that the second Huit sister can cause people to freeze for varying lengths of time by patting her leg, then pointing at them. It’s not something often seen among super heroes or magicians in fiction, but it certainly provides some utility, allowing Durinda to freeze would-be aggressors in their tracks without causing any permanent harm. The weird part is that the leg patting and finger pointing may not be affecting Durinda’s targets’ directly, but is instead turning their own brains against them.

As described in the book, Durinda’s targets freeze up instantly, and remember none of what happens around them until they unfreeze some time later. This indicates that their paralysis isn’t just affecting their motor control like a spinal cord injury would. Combined with the rapid and complete recovery, Durinda’s targets probably aren’t being damaged at all, especially considering most nerve damage is permanent without a lot of outside intervention. The most likely explanation is that Durinda’s pointing is simply putting people to sleep.

Sleeping out of schedule

While we all do a bit of tossing and turning at night, when it comes time for the Rapid Eye Movement (REM) sleep phase, we basically stop moving. REM is the sleep phase where you’re likely to be dreaming, and possibly encoding long-term memories, and it would be dangerous if we accidentally started acting out any of these thoughts. So the brain induces a sort of general paralysis to keep the wiggling to a minimum, and most dreaming is acted out only with a few twitches plus some… rapid eye movement.

Sometimes the order of operations doesn’t work out right though. Some people find that the paralysis is induced when their brain is still conscious instead of dreaming, a sleep disorder called sleep paralysis. It can be a frightening experience, as your limbs suddenly won’t move, you can’t lift your head, and worst of all, it feels like a weight on your chest is making it hard to breathe, even if you’re actually getting a healthy amount of oxygen. Sleep paralysis has been tied to other sleep problems, like apnea and narcolepsy, which may also help explain how Durinda’s power works.

A nod to narcolepsy

Narcolepsy is a neurological disorder that disrupts how the brain controls it’s sleep cycles, or circadian rhythm. People may feel sleepy all day, be wakeful at night, or even experience cataplexy, wherein they lose muscle strength and coordination for a few moments while otherwise staying awake. Sleep paralysis is also a symptom of narcolepsy, and so this package almost sounds like what Durinda’s finger pointing causes in her targets, as they basically have unpredictable symptoms of sleep (and more) during other activities. The catch is that Durinda’s targets are actually falling fully asleep, experiencing paralysis but without the limp muscles of cataplexy.

How a pointed finger can put someone to sleep is still a bit of a mystery. While she may be inducing some short-lived circadian rhythm disorder, it’s probably not an exact match of narcolepsy, as the roots of that disorder of generally thought to be tied to brain injuries, autoimmune problems, or genetic predispositions. Leaving some mystery intact, it still seems like Durinda’s power could be described as inducing a power nap, whether her target wants one or not.

Source: Narcolepsy Fact Sheet, National Institute of Neurological Disorders and Stroke

On June 18th, 2017 we learned about

How Annie Huit’s eight-year-old brain could grow up overnight

Sciencing the Sisters Eight!

From the perspective of an adult reader, the first “power” revealed in The Sisters Eight is a little… underwhelming? Annie, the oldest of the titular octuplets, realizes that she suddenly has the power to “think like an adult,” which she uses to help figure out mysteries, learn to drive a car, and keep her household running in the absence of the girls’ parents. Paying utility bills may seem pretty dull to anyone who regularly does so, but for the eight-year-olds in the story, it represents a task that’s clearly important while also slightly mysterious, and even Annie can’t explain how she knows what needs to be done next.

Double-time development

We never get a full explanation for what happens in Annie’s head either, but there are some scientific concepts that might serve as a model for her instant mental maturity. Our brains change a lot as we grow up, and so there are some concrete differences between an adult and a child’s gray matter. One process that starts before birth is called myelination, which is a way for the brain to insulate the connections between brain cells. A fatty coating called myelin wrapped around axons, the connective tissue to other brain cells, so that they’ll operate more efficiently. As electrical signals are passed from one cell to the next, the myelin keeps that signal strong and on the right track- without it, electrical activity is likely to move more slowly, sometimes failing to activate the next brain cell at all.

Another way a brain ups it’s efficiency as we grow up is to actually remove connections between brain cells in a process called synaptic pruning. Brain circuits that aren’t activated often, such as to differentiate speech sounds nobody in your local language is using, are basically culled from the brain at different phases of development. By getting rid of connections that aren’t in use, the brain makes the route for other activity clearer, and makes space for connections that might actually be part of a person’s experience.

If Annie’s power were to somehow speed up these processes, she’d suddenly find herself with a stabilized, efficient noggin. Learning a second language might get harder, but she’d probably be able to focus and concentrate in a way that other eight-year-olds couldn’t. However, to give her more of a grasp of the adult shoes she was stepping into, she may have also developed some new memories of activities she’d never actually experienced in her life.

Made-up memories

For nearly a decade, researchers have been finding ways to activate brain cells in order to build new memories with a technique called optogenetics. Mouse brains were monitored while they experience various stimuli, like a small shock when walking on a certain platform. The memory of that event was naturally encoded in the brain, and researchers noted which brain cells were used to accomplish that job. Because those mice had brain cells genetically engineered to be sensitive to light, lasers shined at the right brain cells could then reactivate the memory of the shock at will. What’s more, that memory could be activated in a neutral space, basically tricking the mouse into remembering that it had been shocked in that second location as well.

Annie’s Adventures didn’t leave room in the narrative for Annie to have lasers implanted in her head, but the concept may still explain how she understood what was needed to run her parentless household. We don’t know the exact triggering mechanism, but in addition to making her brain structure more like an adult’s, her memory cells could have also been activated to give her the knowledge otherwise acquired over years of experience.

Source: What Causes the Brain to Have Slow Processing Speed, and How Can the Rate Be Improved? by Heather Walker, Scientific American

On June 12th, 2017 we learned about

The visual details you perceive are probably the product of cultural priorities

Where you grow up can shape your politics, your preferences in food and culture, and even what you can see. Thanks to the fact that our visual perceptions of the world are heavily processed and edited by our brains, what we “see” depends a lot on what our brains think is worth seeing. This can lead to seeing things that aren’t really there, or perhaps being more sensitive to certain stimuli than others. Studies of people from who grew up in different cultures have been examining cases where people don’t exactly see eye-to-eye, and some clues are finally emerging to explain why such differences might develop in the first place.

One of these gaps was first officially noted in the 1960s, in the form of some failed optical illusions. The image in question is called the Müller-Lyer illusion, where two to three horizontal lines are presented close to each other in parallel. The only real difference is that each line has simple arrowheads pointed either away from each other or towards each other. It was assumed that everyone saw the line with inward-pointing arrowheads as being longer than its counterparts, but that proved to only be true to people growing up in Western cultures. People less anchored to European traditions, such as the Suku tribespeople from Angola, had no trouble recognizing that the horizontal lines were the same size. Somehow, their brains were never taught to misjudge those proportions, and the jury is still out as to what the basis for this difference is.

Lines versus written languages

A study comparing the perceptions of Americans and Canadians to people raised in Japan may be getting closer to unraveling these sorts of perceptual gaps. Test participants were shown a series of simple vertical lines arranged in a grid, then asked to pick out which segment was different from the others. When that difference was in one line’s length, North Americans were quicker to find a longer line, but slower to find a single shorter line, while Japanese participants showed no preference for either task. Japanese participants did seem to be less attuned to the lines’ angles, taking longer to find a line that was straighter than the others when they were all presented at a slight angle.

This might not represent any deep truth or change in mindset as much as a form of visual training. Our brains do their best to be efficient, and when certain stimuli are important to parse, our brains focus appropriately. When something isn’t reinforced as important, we can ignore it a bit. In the context of this study, researchers suspect that the writing systems that each participant was raised with trained them to notice certain visual details over others. Stroke length is more important in many Asian characters, whereas the angle of stokes in letters conveys meaning in Western scripts (as a crude example, many Japanese fonts don’t even include italic characters). This type of visual specialization might not explain all cultural differences in perception, but the underlying mechanism of how our brains selectively build our view of the world is likely to play a role in any context.

Source: You don’t see what I see?, Scienmag

On June 11th, 2017 we learned about

Working around your brain’s attempts at efficiency to improve your writing

Between her spelling tests, short fiction and book reports, my second grader is discovering how tricky proof-reading your own writing can be. Even though she honestly doesn’t know how to spell or decline every word correctly, she’s at a point where her brain is prioritizing what she wants to say over what’s actually been written. It’s probably a case where our brains are trying to help focus on what is really interesting at any given moment, but since noticing mistakes can be very helpful, it’s good to know when it’s happening and how to work around it.

Many errors are hard to spot not because they’re unrecognizable to the reader, but just because our brains are great at “fixing” reality for us. Blind spots in our vision can be “patched” with fabricated information. Words can be recognized as concepts, instead of carefully read. When it comes to something you’ve written, the framework of your ideas is probably important enough to hold your attention, and so minor holes or errors in your writing can be glossed over, especially after you’ve convinced yourself that you’ve written everything you need to.

Making the most of mistakes

Ignoring mistakes can become a problem, and not just for readers who might be confused by disjointed, incomplete or just misspelled prose. At a certain point, ignoring mistakes stunts the growth of your skills. A study Hans Schroder at Michigan State University had kids play a simple video game while monitoring how much they paid attention to their errors with electrode-lined caps. Kids who’s brains barely registered mistakes were more likely to continue making similar errors than kids who seemed to slow down to consider each error. These differences in attention were less than a second each, but researchers believe that kids who frame their mistakes as tools to enable their development, thinking referred to as a “growth” mindset, were quite successful at doing exactly that.

Writing is not reading

So how do you make the most of your typos, run-on sentences and tense disagreements? Even if rereading your document yields no corrections right after you right it, don’t worry— part of your brain probably caught something that could be better, and you just need to find ways to stop thinking about your ideas and instead focus on what’s actually on the page (or screen.) Some of the easiest ways to do that are to stop thinking like a writer, and shift the context of your reading to make your own words just a bit less familiar. That way, your brain will be more likely to investigate what’s there instead of what it thinks should be there.

A quick option is to change your font or coloration when you read, so that your work doesn’t look like the same document. Print it out, and edit with a pen in hand. Read your words out loud to really shift your mental context. Even better, have a friend read it out loud. Or, if you have the luxury of time, come back at a different time and do your editing after your brain isn’t carrying the same set of assumptions around.

Some of this may be overkill for a soon-to-be third grader, but even a book report isn’t likely to be perfect on the first pass.

Source: What’s Up With That: Why It’s So Hard to Catch Your Own Typos by Nick Stockton, Wired

On June 6th, 2017 we learned about

Macaque monkeys demonstrate how our brains sort through the faces we see

How long does it take you to identify a person’s face? If you’ve gotten a good view of someone, you’re probably not even aware of the work your brain is doing to recognize the shapes in front of you as a person’s face. Even if the process of piecing together the exact curve of a cheekbone, the texture of a forehead and the cleft of a chin can happen without you noticing, it’s only possible thanks to the specialized brain structures handling the task. Researchers have been honing in on the exact formula brains use to make sense of all these features, finding that as few as 50 attributes can be sufficient to help you spot your neighbor in a crowded room in the blink of an eye.

Putting the pieces together

Researchers have known for some time about a section of the brain called the fusiform face area, but to see it in action they watched the brains of macaque monkeys who were looking at photos. Fortunately, the specialized neurons that recognize faces evolved in a shared ancestor don’t get too picky about the species of the viewed face, and the monkeys’ brains responded to pictures of humans in the same way they would look at closer kin. As the monkeys looked at the pictures, the activity of just 205 neurons was closely monitored to see which specific sites were needed to parse a face. That recorded data was parsed into 50 types of visual data, such as face shape, distance between the eyes, or skin texture. To build a face in the brain, each of these attributes were basically analyzed by different neurons in parallel, then assembled into the rational image we consciously recognize.

Observing all this activity in the macaque monkey brains was important, but to see if that activity was functioning the way researchers hypothesized, a test was needed. The process was then reversed to see if it would created the expected result— in this case, a face that looked like the face seen in the photos. Activity from the monitored neurons was translated back into visual information, then assembled digitally. The faces synthesized from the monkey’s brain cells weren’t perfect clones, but they were close enough that you’d recognize the person in the image.

Special functions just for faces?

As visual, social animals, it’s not a shock that our brains, and those of the macaques, carry such a fine-tuned toolkit for spotting faces. If anything, the system may be too sensitive, forcing us to think of a face every time we see two dots above a line. For researchers, the next question is to see just how specialized this facial recognition is. When looking at objects that aren’t quite as exciting as a potential friend, mate or rival, do our brains sort things in the same way? Or does our brain recognize chairs or trees in a different way, putting facial recognition in its own category of perception?

Source: Photos of human faces reassembled from monkeys’ brain signals by Andy Coghlan, New Scientist