Color my world

When you think about it, color perception is really strange.

Just about all of us have wondered whether we all see colors the same way -- if, for example, what you see as blue is the same as what I see as yellow, but we both identify them using the same word because there's no way to know we're not seeing them the same way.  I've always thought that unlikely.  After all, with few exceptions (other than genetic or structural abnormalities, about which q. v.) our eyes and brain are all built on the same basic plan.  I guess it's possible that we each see the world's colors differently, but the most parsimonious explanation is that because the underlying structures are the same, we're all pretty much perceiving identical color palettes.

Of course, there's no way to know for certain, and I ran into two things just in the last couple of days that leave me wondering.

The first is a curious conversation I had with my friend, the awesome writer Andrew Butters, whose books -- especially the staggeringly good Known Order Girls -- should be on everyone's TBR list.  It started out with an amusing discussion of words that sound like they should mean something else.  One of Andrew's was ambulatory, which to him sounds like "someone who is so incapacitated they need an ambulance."  I personally believe that pulchritude should mean "something that makes you want to puke," and not what it actually does, which is "beauty."  And then Andrew mentioned that he always thought the color words vermilion and chartreuse were wrong, and in fact backwards -- that vermilion should mean a light green and chartreuse a bright orangey-red.

This struck me as really weird, because those two words have never given me that sense.  This may be because I've known them both since I was little.  I knew vermilion because I grew up a mile away from Vermilion Bayou, so named because the red mud of southern Louisiana stains the water reddish brown.  Chartreuse I knew because my grandma's employer, Father John Kemps, was an eccentric, bookish, cigar-smoking Dutch expat who was very fond of a post-meal tipple and loved chartreuse, the pale green herbal French liqueur from which the color got its name.

So I asked Andrew where his misapprehension came from.  He said he wasn't sure, but that perhaps the vermilion one came from the French vert (green); Andrew, like most Canadians, is English-French bilingual.  But where his thinking chartreuse should mean "red" came from, he had no idea.

What baffled me further, though, was when he pointed out that he's not alone in this.  There's a whole page on Reddit about thinking that vermilion and chartreuse are backwards, and an astonishing number of people chimed in to say, "Yeah, me too!"  So why those particular words, and not another pair?  Why not citron and azure, or something?

The second is that I'm finally getting around to reading Oliver Sacks's book An Anthropologist on Mars, which has to do with the intersection between neurological disorders and creativity.  The very first chapter is about a painter who was in a car accident that resulted in brain damage causing cerebral achromotopsia -- complete colorblindness due not to abnormalities in the cones of the retina, but because of damage to a region of the brain called the V4 prestriate cortex.  Afterward, he saw the world in shades of gray -- but with some distinct oddities, because pure white surfaces looked "dirty" or "smudged" to him, red looked black, and blue looked a pale gray.

This brought up an interesting discussion about how we see color in the first place, and that color perception (even within a single, normally-sighted individual) isn't absolute, but comparative; we assess the color value of a region by comparison to the entire visual field.  If the whole "what color is this dress?" thing that was going around a few years ago didn't convince you of that, try this one out:

Every one of these spheres is exactly the same color; they were, in fact, cut-and-pasted from a single image.  The only thing that differs is the color of the foreground stripes that cross each one.  But since your eyes judge color based on context, it's impossible to see them as the same even once you cognitively know what's going on.

Don't believe it?  If you go to the link provided, the article author (the wonderful Phil Plait) created an animation that cycles between the image with and without the stripes.  It's mind-blowing.

All of this circles around to the weird topic of synesthesia, which is a still-unexplained sensory phenomenon where people have a sort of cross-wiring between two senses.  Russian composer Alexander Scriabin was a synesthete, who experienced sensations of colors when he heard chords; C# minor, for example, looked a bright emerald green.  (If you want to find out more, the amazing book by Richard Cytowic, The Man Who Tasted Shapes, is still considered one of the seminal works on this odd disorder.)

I wonder if what Andrew (and the others with the vermilion-chartreuse switch) are experiencing is a form of synesthesia.  A former student of mine is a synesthete for whom printed letters (and whole words) evoke sensations of colors, so his word choices while writing took into account whether the colors were harmonious, not just that the words made semantic sense.  (I hasten to add that he was and is one of the most brilliant people I've ever known, so his synesthesia didn't cause his writing to lack any clarity to non-synesthetes like myself -- although it has been known to slow him down as he struggled to find words that satisfied both meaning and appearance.)  So perhaps the "vermilion = light green" thing comes from the fact that for Andrew and the others on the Reddit page, the word looks green irrespective of its association with an actual (different) color.

What I find odd still, though, is that so many people have those two particular color words backwards.  Synesthesia is remarkably individual; while one of its hallmarks is a complete consistency within a particular person (Scriabin always saw C# minor as green, for example), it varies greatly from person to person.  The fact that vermilion and chartreuse are reversed for so many people is just plain peculiar.

So there's still a lot we don't know about how exactly we perceive color, and maybe my "parsimonious" explanation that (other than those with colorblindness, synesthesia, and other visual disorders) we're all seeing colors more or less the same way fails to capture the complexity of the real world.  Wouldn't be the first time I've thought things were simpler than they turned out to be.  Maybe it's just my perception because I'm a non-synesthete with intact color vision.

But until we're somehow able to see things through someone else's eyes and brain, that's a limitation I can't escape except for in my imagination.

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Mechanical brain transplant

New from the "Well, I can't see any way that could go wrong, do you?" department, we have: scientists growing Neanderthal brain fragments in petri dishes and then connecting them to crab-like robots.

My first thought was, "Haven't you people ever watched a science fiction movie?"  This feeling may have been enhanced by the fact that just a couple of days ago I watched the Doctor Who episode "The End of the World," wherein the Doctor and his companion are damn near killed (along with everyone else on a space station) when a saboteur makes the shields malfunction using little scuttling metallic bugs.

The creator of the Neanderthal brain bits is Alysson Muotri, geneticist at the University of California - San Diego's School of Medicine.  He and his team isolated genes that belonged to our closest cousins, Homo sapiens neanderthalensis, and transferred them into stem cells.  Then, they allowed the cells to grow into proto-brains to see what sorts of connections would form.

Muotri says, "We're trying to recreate Neanderthal minds."  So far, they've noticed an abnormally low number of synapses (as compared to modern humans), and have speculated that this may indicate a lower capacity for sophisticated social behavior.

But Muotri and his team are going one step further.  They are taking proto-brains (he calls them "organoids") with no Neanderthal genes, and wiring them and his "neanderthalized" versions into robots, to make comparisons about how they learn.  Simon Fisher, a geneticist for the Department of Psycholinguistics at the Max Planck Institute, said, "It's kind of wild.  It's creative science."

That it is.

I have to admit there's a cool aspect to this.  I've always wondered about the Neanderthals.  During the peak of their population, they actually had a brain capacity larger than modern humans.  They clearly had culture -- they ceremonially buried their dead, probably had language (as they had the same variant of the "linguistic gene" FOXP2 that we do), and may have even made music, to judge by what appears to be a piece of a 43,000 bone flute that was found in Slovenia.

All that said, I'm not sure how smart it would be to stick a Neanderthal brain inside a metallic crab.  If this was a science fiction movie, the next thing that happened would be that Muotri would be in his lab late at night working with his Crab Cavemen, and he'd turn his back and they'd swarm him, and the next morning all that would be found is his skeleton, minus his femur, which would have been turned into a clarinet.

Okay, I know I'm probably overreacting here.  But it must be admitted that our track record of thinking through our decisions is not exactly unblemished.  Muotri assures us that these little "organoids" have no blood supply and therefore no potential for developing into an actual brain, but still.  I hope he knows what he's doing.  As for me, I'm going to go watch Doctor Who.

Let's see, what's the next episode?  "Dalek."  *reads description*  "A superpowerful mutant intelligence controlling a mechanical killing device goes on a rampage and attempts to destroy humanity."

Um, never mind.  *switches channel to Looney Tunes*

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Facing facts

"I'm sorry, but I have no idea who you are."

I can't tell you how many times I've had to utter that sentence.  Regular readers of Skeptophilia know why; I have a peculiar disability called prosopagnosia, or "face blindness."  I have a nearly complete inability to recognize faces, even of people I've known for some time.

Well, that's not exactly true.  I recognize people differently than other people do.  I remember the people I know as lists of features.  I know my wife has curly brown hair and freckles and an infectious smile, but I honestly have no mental image of her.  I can't picture my own face, although -- like with my wife -- I could list some of my features.

That system doesn't have a high success rate, however, and a lot of the time I have no idea who the people around me are, especially in a place where there are few clues from context.  I have pretty serious social anxiety, and my condition makes it worse, having put me in the following actual situations:

• introducing myself twice to the same person at a party
• getting a big, enthusiastic hug and an "it's been so long!" from someone in our local gym, and never figuring out who I was talking to
• having two of my students switch seats and not realizing it for three weeks, until finally they 'fessed up
• going to see a movie, and not knowing until the credits rolled that the main characters were played by Kenneth Branagh, Penelope Cruz, Judi Dench, Derek Jacobi, Michelle Pfeiffer, Daisy Ridley, and Johnny Depp
• countless incidents of my fishing for clues ("so, how's your, um... spouse, parents, kids, pets, job..."), sometimes fruitlessly

My anxiety has made me really good at paying attention to, and recalling, other cues like voice, manner of dress, posture, walk, hair style, and so on.  But when one or more of those change -- such as with the student I had one year who cut her hair really short during the summer, and whom I didn't recognize when she showed up in one of my classes on the first day of school the following year -- it doesn't always work.

One up side to the whole thing is that I do get asked some funny questions.  One student asked me if when I looked at people, their faces were invisible.  Another asked me if when I look in the bathroom mirror in the morning, I don't know that's me.  (It's a pretty shrewd guess that it is me, since there's generally no one else in there at the time.)

But at least it's not as bad as the dumb questions that my former students who are identical triplets sometimes get.  One of them was once asked by a friend how she kept track of which triplet she was.

No, I'm not kidding.  Neither, apparently, was the person who asked the question.

[Image licensed under the Creative Commons Randallbritten, FaceMachine screenshots collage, CC BY-SA 3.0]

In any case, all of this comes up because of some research that came out in the journal Cortex that tried to parse what's happening (or what's not happening) in the brains of people like me.  Some level of prosopagnosia affects about one person in fifty; some of them lose their facial recognition ability because of a stroke or other damage to the fusiform gyrus, the part of the brain that seems to be a dedicated face-memory module.  Others, like me, were born this way.  Interestingly, a lot of people who have lifelong prosopagnosia take a while to figure it out; for years, I just thought I was unobservant, forgetful, or a little daft.  (All three of those might be true as well, of course.)  It was only after I had enough embarrassing incidents occur, and -- most importantly -- saw an eye-opening piece about face blindness by Leslie Stahl on 60 Minutes, that I realized what was going on.

In any case, the paper in Cortex looked at trying to figure out why people who are face-blind often do just fine on visual perception tests, then fail utterly when it comes to remembering photographs of faces.  The researchers specifically tried to parse whether the difference was coming from an inability to connect context cues to the face you're seeing (e.g., looking at someone and thinking, "She's the woman who was behind the counter at the library last week") versus simple familiarity (the more nebulous and context-free feeling of "I've seen that person before").  They showed each test subject (some of whom weren't face-blind) a series of 120 faces, then a second series of 60 faces where some of them were new and some of them were in the previous series.  The researchers were not only looking for whether the subjects could correctly pick out the old faces, but how confident they were in their answers -- the surmise being that low confidence on correct answers was an indicator of relying on familiarity rather than context memory.

The prosopagnosics in the test group not only were bad at identifying which faces were old and which ones they'd seen before; but their confidence was really low, even on the ones they got right.  Normally-sighted people showed a great deal more certainty in their answers.  What occurs to me, though, is that knowing they're face-blind would skew the results, in that we prosopagnosics are always doubtful we're recalling correctly.  So these data could be a result of living with the condition, not some kind of underlying mechanism at work.  I almost never greet someone first, because even if I think I might know them, I'm never certain.  A lot of people think I'm aloof because of this, but the reality is that I honestly don't know which of the people I'm seeing are friends and which are total strangers.

One thing about the researchers' conclusion does ring true, however.  The subconscious "feeling of familiarity" is definitely involved.  My experience of face blindness isn't that I feel like I'm surrounded by strangers; it's more that everyone looks vaguely familiar.  The problem is, that feeling is no stronger when I see a close friend than when I see someone I've never met before, so the intensity of that sense -- what apparently most people rely on -- doesn't help me.

So that's the view of the world through the eyes of someone who more often than not doesn't know who he's looking at.  Fortunately for me, (1) at this point in my life I'm unembarrassed by my condition, and (2) most of the people in my little village know I'm face-blind and will say, "Hi, Gordon, it's Steve..." when they walk up, and spare me the awkwardness of fishing for clues.  (Nota bene: This only works if it actually is Steve.  Otherwise it would be even more awkward.)  But hopefully some good will come from this research, because face blindness is kind of a pain in the ass.

"Our results underscore that prosopagnosia is a far more complex disorder that is driven by more than deficits in visual perception," said study first author Anna Stumps, a researcher in the Boston Attention Learning Laboratory at VA Boston.  "This finding can help inform the design of new training approaches for people with face blindness."

Which would be really, really nice.

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In the blink of an eye

One of the things I love about science is how it provides answers to questions that are so ordinary that few of us appreciate how strange they are.

I remember how surprised I was when I first heard a question about our vision that had honestly never occurred to me.  You know how images jump around when you're filming with a hand-held videocamera?  Even steady-handed people make videos that are seriously nausea-inducing, and when the idea is to make it look like it's filmed by amateurs -- such as in the movie The Blair Witch Project -- the result looks like it was produced by strapping a camera to the head of a kangaroo on crack.

What's a little puzzling is why the world doesn't appear to jump around like that all the time.  I mean, think about it; if you walk down the hall holding a videocamera on your shoulder, and watch the video and compare it to the way the hall looked while you were walking, you'll see the image bouncing all over the place on the video, but won't have experienced that with your eyes.  Why is that?

The answer certainly isn't obvious.  One guess scientists have is that we stabilize the images we see, and compensate for small movements of our head, by using microsaccades -- tiny, involuntary, constant jitters of the eyes.  The thought is that those little back-and-forth movements allow your brain to smooth out the image, keeping us from seeing the world as jumping around every time we move.

Another question about visual perception that I had never thought about was the subject of some research out of New York University and the University Medical Center of Göttingen that was published in the journal Current Biology.  Why don't you have the perception of the world going dark for a moment when you blink?  After all, most of us blink about once every five seconds, and we don't have the sense of a strobe effect.  In fact, most of us are unaware of any change in perception whatsoever.

[Image licensed under the Creative Commons Mcorrens, Iris of the Human Eye, CC BY-SA 3.0]

By studying patients who had lesions in the cerebrum, and comparing them to patients with intact brains, the scientists were not only able to answer this question, but to pinpoint exactly where this phenomenon happens -- the dorsomedial prefrontal cortex, a part of the brain immediately behind the forehead.  What they found was that individuals with an intact dmPFC store a perceptual memory of what they've just seen, and use that to form the perception they're currently seeing, so the time during which there's no light falling on the retina -- when you blink -- doesn't even register.  On the other hand, a patient with a lesion in the dmPFC lost that ability, and didn't store immediate perceptual memories.  The result?  Every time she blinked, it was like a shutter closed on the world.

"We were able to show that the prefrontal cortex plays an important role in perception and in context-dependent behavior," said neuroscientist Caspar Schwiedrzik, who was lead author of the study.  "Our research shows that the medial prefrontal cortex calibrates current visual information with previously obtained information and thus enables us to perceive the world with more stability, even when we briefly close our eyes to blink...  This is not only true for blinking but also for higher cognitive functions.  Even when we see a facial expression, this information influences the perception of the expression on the next face that we look at."

All of which highlights that all of our perceptual and integrative processes are way more sophisticated than they seem at first.  It also indicates something that's a little scary; that what we're perceiving is partly what's really out there, and partly what our brain is telling us it thinks is out there.  Which is right more often than not, of course.  If that weren't true, natural selection would have finished us off a long time ago.  But that fraction of the times that it's wrong, it can create some seriously weird sensations -- or make us question things that we'd always taken for granted.

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Watch your tone!

You probably know that there are many languages -- the most commonly-cited are Mandarin and Thai -- that are tonal.  The pitch, and pitch change across a syllable, alter its meaning.  For example, in Mandarin, the syllable "ma" spoken with a high steady tone means "mother;" with a falling then rising tone, it means "horse."

If your mother is anything like mine was, confusing these is not a mistake you'd make twice.

A pitch vs. time graph of the five tones in Thai [Image licensed under the Creative Commons Thtonesen.jpg: Lemmy Laffer derivative from Bjankuloski06en, Thai tones, CC BY-SA 3.0]

English is not tonal, but there's no doubt that pitch and stress change can communicate meaning.  The difference is that pitch alterations in English don't change the denotative (explicit) meaning, but can drastically change the connotative (implied) meaning.  Consider the following sentence:

He told you he gave the package to her?

Spoken with a neutral tone, it's simply an inquiry about a person's words and actions.  Now, one at a time, change which word is stressed:

• He told you he gave the package to her?  (Implies the speaker was expecting someone else to do it.)
• He told you he gave the package to her? (Implies surprise that you were told about the action.)
• He told you he gave the package to her? (Implies surprise that you were the one told about it)
• He told you he gave the package to her? (Implies the speaker expected the package should have been paid for)
• He told you he gave the package to her? (Implies that some different item was expected to be given)
• He told you he gave the package to her? (Implies surprise at the recipient of the package)

Differences in word choice can also create sentences with identical denotative meanings and drastically different connotative meanings.  Consider "Have a nice day" vs. "I hope you manage to enjoy your next twenty-four hours," and "Forgive me, Father, for I have sinned" vs. "I'm sorry, Daddy, I've been bad."

You get the idea.

All of this is why mastery of a language you weren't born to is a long, fraught affair.

The topic comes up because of some new research out of Northwestern University that identified the part of the brain responsible for recognizing and abstracting meaning from pitch and inflection -- what linguists call the prosody of a language.  A paper this week in Nature Communications showed that Heschl's gyrus, a small structure in the superior temporal lobe, actively analyzes spoken language for subtleties of rhythm and tone and converts those perceived differences into meaning.

"Our study challenges the long-standing assumptions how and where the brain picks up on the natural melody in speech -- those subtle pitch changes that help convey meaning and intent," said G. Nike Gnanataja, who was co-first author of the study.  "Even though these pitch patterns vary each time we speak, our brains create stable representations to understand them."

"The results redefine our understanding of the architecture of speech perception," added Bharath Chandrasekaran, the other co-first author.  "We've spent a few decades researching the nuances of how speech is abstracted in the brain, but this is the first study to investigate how subtle variations in pitch that also communicate meaning are processed in the brain."

It's fascinating that we have a brain area dedicated to discerning alterations in the speech we hear, and curious that similar research on other primates shows that while they have a Heschl's gyrus, it doesn't respond to changes in prosody.  (What exact role it does have in other primates is still a subject of study.)  This makes me wonder if it's yet another example of preaptation -- where a structure, enzyme system, or gene evolves in one context, then gets co-opted for something else.  If so, our ancestors' capacity for using their Heschl's gyri to pick up on subtleties of speech drastically enriched their abilities to encode meaning in language.

But I should wrap this up, because I need to go do my Japanese language lessons for the day.  Japanese isn't tonal, but word choice strongly depends on the relative status of the speaker and the listener, so which words you use is critical if you don't want to be looked upon as either boorish on the one hand, or putting on airs on the other.

I wonder how the brain figures all that out?

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Remembrance of things past

"The human brain is rife with all sorts of ways of getting it wrong."

This quote is from a talk by eminent astrophysicist Neil deGrasse Tyson, and is just about spot on.  Oh, sure, our brains work well enough, most of the time; but how many times have you heard people say things like "I remember that like it was yesterday!" or "Of course it happened that way, I saw it with my own eyes"?

Anyone who knows something about neuroscience should immediately turn their skepto-sensors up to 11 as soon as they hear either of those phrases.

fMRI scan of a human brain during working memory tasks [Image is in the Public Domain courtesy of the Walter Reed National Military Medical Center]

Our memories and sensory-perceptual systems are selective, inaccurate, heavily dependent on what we're doing at the time, and affected by whether we're tired or distracted or overworked or (even mildly) inebriated.  Sure, what you remember might have happened that way, but -- well, let's just say it's not as much of a given as we'd like to think.  An experiment back in 2005 out of the University of Portsmouth looked memories of the Tavistock Square (London) bus bombing, and found that a full forty percent of the people questioned had "memories" of the event that were demonstrably false -- including a number of people who said they recalled details from CCTV footage of the explosion, down to what people were wearing, who showed up to help the injured, when police arrived, and so on.

Oddly enough, there is no CCTV footage of the explosion.  It doesn't exist and has never existed.

Funny thing that eyewitness testimony is considered some of the most reliable evidence in courts of law, isn't it?

There are a number of ways our brains can steer us wrong, and the worst part of it all is that they leave us simultaneously convinced that we're remembering things with cut-crystal clarity.  Here are a few interesting memory glitches that commonly occur in otherwise mentally healthy people, that you might not have heard of:

• Cryptomnesia.  Cryptomnesia occurs when something from the past recurs in your brain, or arises in your external environment, and you're unaware that you've already experienced it.  This has resulted in several probably unjustified accusations of plagiarism; the author in question undoubtedly saw the text they were accused of plagiarizing some time earlier, but honestly didn't remember they'd read it and thought that what they'd come up with was entirely original.  It can also result in some funnier situations -- while the members of Aerosmith were taking a break from recording their album Done With Mirrors, they had a radio going, and the song "You See Me Crying" came on.  Steven Tyler said he thought that was a pretty cool song, and maybe they should record a cover of it.  Joe Perry turned to him in incredulity and said, "That's us, you fuckhead."

• Semantic satiation.  This is when a word you know suddenly looks unfamiliar to you, often because you've seen it repeatedly over a fairly short time.  Psychologist Chris Moulin of Leeds University did an experiment where he had test subjects write the word door over and over, and found that after a minute of this 68% of the subjects began to feel distinctly uneasy, with a number of them saying they were doubting that "door" was a real word.  I remember being in high school writing an exam in an English class, and staring at the word were for some time because I was convinced that it was spelled wrong (but couldn't, of course, remember how it was "actually" spelled).

• Confabulation.  This is the recollection of events that never happened -- along with a certainty that you're remembering correctly.  (The people who claimed false memories of the Tavistock Square bombing were suffering from confabulation.)  The problem with this is twofold; the more often you think about the false memory or tell your friends and family about it, the more sure you are of it; and often, even when presented with concrete evidence that you're recalling incorrectly, somehow you still can't quite believe it.  A friend of mine tells the story of trying to help her teenage son find his car keys, and that she was absolutely certain that she'd seen them that day lying on a blue surface -- a chair, tablecloth, book, she wasn't sure which, but it was definitely blue.  They turned the house upside down, looking at every blue object they could find, and no luck.  Finally he decided to walk down to the bus stop and take the bus instead, and went to the garage to get his stuff out of the car -- and the keys were hanging from the ignition, where he'd left them the previous evening.  "Even after telling me this," my friend said, "I couldn't accept it.  I'd seen those keys sitting on a blue surface earlier that day, and remembered it as clearly as if they were in front of my face."

• Declinism.  This is the tendency to remember the past as more positive than it actually was, and is responsible both for the "kids these days!" thing and "Make America Great Again."  There's a strong tendency for us to recall our own past as rosy and pleasant as compared to the shitshow we're currently immersed in, irrespective of the fact that violence, bigotry, crime, and general human ugliness are hardly new inventions.  (A darker aspect of this is that some of us -- including a great many MAGA types -- are actively longing to return to the time when straight White Christian men were in charge of everything; whether this is itself a mental aberration I'll leave you to decide.)  A more benign example is what I've noticed about travel -- that after you're home, the bad memories of discomfort and inconveniences and delays and questionable food fade quickly, leaving behind only the happy feeling of how much you enjoyed the experience.

• The illusion of explanatory depth.  This is a dangerous one; it's the certainty that you understand deeply how something works, when in reality you don't.  This effect was first noted back in 2002 by psychologists Leonid Rozenblit and Frank Keil, who took test subjects and asked them to rank from zero to ten their understanding of how common devices worked, including zippers, bicycles, electric motors, toasters, and microwave ovens, and found that hardly anyone gave themselves a score lower than five on anything.  Interestingly, the effect vanished when Rozenblit and Keil asked the volunteers actually to explain how the devices worked; after trying to describe in writing how a zipper works, for example, most of test subjects sheepishly realized they actually had no idea.  This suggests an interesting strategy for dealing with self-styled experts on topics like climate change -- don't argue, ask questions, and let them demonstrate their ignorance on their own.

• Presque vu.  Better known as the "tip-of-the-tongue" phenomenon -- the French name means "almost seen" -- this is when you know you know something, but simply can't recall it.  It's usually accompanied by a highly frustrating sense that it's right there, just beyond reach.  Back in the days before The Google, I spent an annoyingly long time trying to recall the name of the Third Musketeer (Athos, Porthos, and... who???).  I knew the memory was in there somewhere, but I couldn't access it.  It was only after I gave up and said "to hell with it" that -- seemingly out of nowhere -- the answer (Aramis) popped into my head.  Interestingly, neuroscientists are still baffled as to why this happens, and why turning your attention to something else often makes the memory reappear.

So be a little careful about how vehemently you argue with someone over whether your recollection of the past or theirs is correct.  Your version might be right, or theirs -- or it could easily be that both of you are remembering things incompletely or incorrectly.  I'll end with a further quote from Neil deGrasse Tyson: "We tend to have great confidence in our own brains, when in fact we should not.  It's not that eyewitness testimony by experts or people in uniform is better than that of the rest of us; it's all bad....  It's why we scientists put great faith in our instruments.  They don't care if they've had their morning coffee, or whether they got into an argument with their spouse -- they get it right every time."

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Word search

I've always wondered why words have the positive or negative connotations they do.

Ask people what their favorite and least-favorite sounding words are, and you'll find some that are easily explicable (vomit regularly makes the "least-favorite" list), but others are kind of weird.  A poll of linguists identified the phrase cellar door as being the most beautiful-sounding pair of words in the English language -- and look at how many names from fantasy novels have the same cadence (Erebor, Aragorn, Celeborn, Glorfindel, Valinor, to name just a handful from the Tolkien mythos).  On the other hand, I still recall passing a grocery store with my son one day and seeing a sign in the window that said, "ON SALE TODAY: moist, succulent pork."

"There it is," my son remarked.  "A single phrase made of the three ugliest words ever spoken."

Moist, in fact, is one of those universally loathed words; my surmise is the rather oily sound of the /oi/ combination, but that's hardly a scholarly analysis.  The brilliant British comedian Miranda Hart had her own unique take on it:

Another question is why some words are easier to bring to mind than others. This was the subject of a fascinating paper in Nature Human Behavior titled, "Memorability of Words in Arbitrary Verbal Associations Modulates Memory Retrieval in the Anterior Temporal Lobe," by neuroscientists Weizhen Xie, Wilma A. Bainbridge, Sara K. Inati, Chris I. Baker, and Kareem A. Zaghloul of the National Institute of Health.  Spurred by a conversation at a Christmas party about why certain faces are memorable and others are not, study lead author Weizhen Xie wondered if the same was true for words -- and if so, that perhaps it could lead to more accuracy in cognitive testing for patients showing memory loss or incipient dementia.

"Our memories play a fundamental role in who we are and how our brains work," Xie said in an interview with Science Daily.  "However, one of the biggest challenges of studying memory is that people often remember the same things in different ways, making it difficult for researchers to compare people's performances on memory tests.  For over a century, researchers have called for a unified accounting of this variability.  If we can predict what people should remember in advance and understand how our brains do this, then we might be able to develop better ways to evaluate someone's overall brain health."

What the team did is as fascinating as it is simple; they showed test subjects pairs of functionally-unrelated words (say, "hand" and "apple"), and afterward, tested them by giving them one word and asking them to try to recall what word it was paired with.  What they found is that some words were easy to recall regardless of what they were paired with and whether they came first or second in the pair; others were more difficult, again irrespective of position or pairing.

"We saw that some things -- in this case, words -- may be inherently easier for our brains to recall than others," said study senior author Kareem Zaghloul.  "These results also provide the strongest evidence to date that what we discovered about how the brain controls memory in this set of patients may also be true for people outside of the study."

[Image licensed under the Creative Commons Mandeep Singh, Emotions words, CC BY 4.0]

Neither the list of easy-to-remember words nor the list of harder-to-remember ones show any obvious commonality (such as abstract versus concrete nouns, or long words versus short ones) that would explain the difference.  Each list included some extremely common words and some less common ones -- tank, doll, and pond showed up on the memorable list, and street, couch, and cloud on the less-memorable list.  It was remarkable how consistent the pattern was; the results were unequivocal even when the researchers controlled for such factors as educational level, age, gender, and so on.

"We thought one way to understand the results of the word pair tests was to apply network theories for how the brain remembers past experiences," Xie said.  "In this case, memories of the words we used look like internet or airport terminal maps, with the more memorable words appearing as big, highly trafficked spots connected to smaller spots representing the less memorable words.  The key to fully understanding this was to figure out what connects the words."

The surmise is that it has to do with the way our brains network information.  Certain words might act as "nodes" -- memory points that connect functionally to a great many different concepts -- so the brain more readily lands on those words when searching.  Others, however familiar and common they might be, act more as "dead-ends" in brain networking, making only a few conceptual links.  Think of it as trying to navigate through a city -- some places are easy to get to because there are a great many paths that lead there, while others require a specific set of roads and turns.  In the first case, you can get to your destination even if you make one or two directional goofs; in the second, one wrong turn and you're lost.

All of which is fascinating. I know as I've gotten older I've had the inevitable memory slowdown, which most often manifests as my trying to recall a word I know that I know. I often have to (with some degree of shame) resort to googling something that's a synonym and scanning down the list until I find the word I'm looking for, but it makes me wonder why this happens with some words and not with others.  Could it be that in my 64-year-old brain, bits of the network are breaking down, and this affects words with fewer working functional links than ones with a great many of them?

All speculation, of course. I can say that whatever it is, it's really freakin' annoying.  But I need to wrap up this post, because it's time for lunch.  Which is -- I'm not making this up -- leftover moist, succulent pork.

I'll try not to think about it.

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Face forward

Life with prosopagnosia is peculiar sometimes.

Better known as "face blindness," it's a partial or complete inability to recognize people's faces.  I'm not sure where I fall on the spectrum -- I'm certainly nowhere as bad as neuroscientist and author Oliver Sacks, who didn't recognize his own face in the mirror.  Me, I'm hampered by it, but have learned to compensate by being very sensitive to people's voices and how they move.  (I've noticed that I'm often more certain who someone is if I see them walking away than I am if they're standing right in front of me.)

Still, it results in some odd situations sometimes.  I volunteer once a week as a book sorter at our local Friends of the Library book sale, and there's this one guy named Rich who is absolutely a fixture -- he always seems to be there.  I've seen him and spoken with him at least a hundred times.  Well, a couple of weeks ago, I was working, and there was this guy who was behind the counter, messing with stuff.  I was about to ask who he was and what he was doing, when he said something, and I realized it was Rich -- who had shaved off his facial hair.

Until he opened his mouth, I honestly had no idea I'd ever seen him in my life.

Then, a couple of nights ago, my wife and I were watching the Doctor Who Christmas episode "Joy to the World," and afterward got to see a thirty-second teaser trailer for season two, which is being released next spring.  Well, in season one, there was this mysterious recurring character named Mrs. Flood (played by British actress Anita Dobson) whose role we have yet to figure out, and who has the Who fandom in quite the tizzy.  And in the trailer, there's a quick clip of an old woman in formal attire watching a theater performance through opera glasses, and until another fan said, "What did you think about the appearance of Mrs. Flood in the trailer?" I had no clue -- not the least suspicion -- that it was her.

So it's kind of inconvenient, sometimes.  When people post still shots from movies or television shows on social media, I usually not only don't know who the actors are, I have no idea what film it's from (unless there's an obvious clue from the setting).  And as I've related before, there are times when even my voice-recognition strategy hasn't worked, and I've had entire conversations with people and then left still not knowing who it was I'd been talking to.

The reason the topic comes up (again) is some research out of Toyohashi University of Technology that was the subject of a paper in the Journal of Vision last week.  The researchers were trying to figure out if humans have a better innate ability to filter out extraneous visual distractions when it comes to facial recognition than they do for recognizing other objects.  Using a technique called "continuous flash suppression" (CFS), they presented volunteers with fast-moving high-contrast images in one eye, and a target image in the other, then using an fMRI measured how long it took the brain's visual recognition centers to "break through" the distraction and recognize the target image.

If the target image was a face -- or "face-like" -- that breakthrough happened much faster than it did with any other sort of image.  And, interestingly, the breakthrough time was significantly slowed for faces that were upside-down.

We're wired, apparently, to recognize right-side-up human faces faster than just about anything else.

"Our study shows that even vague, face-like images can trigger subconscious processing in the brain, demonstrating how deeply rooted facial recognition is in our visual system," said Makoto Michael Martinsen, who co-authored the study.  "This ability likely evolved to help us prioritize faces, which are critical for social interaction, even when visual information is scarce...  [However] we didn’t consider factors like emotion or attractiveness, which can affect facial perception...  Despite this, our study highlights the brain’s incredible ability to extract important information from minimal cues, especially when it comes to faces.  It emphasizes the importance of facial features in both conscious and subconscious perception and raises interesting questions about how this mechanism evolved."

Naturally, I found myself wondering how face-blind people like myself would do in this task.  After all, it's not that we can't tell something is a face; it's that the visual information in a face doesn't trigger the same instantaneous recall it does in other people.  When I do recognize someone visually, it's more that I remember a list of their features -- he's the guy with square plastic frame glasses and curly gray hair, she's the woman with a round face and dark brown eyes who favors brightly-colored jewelry.  This, of course, only takes me so far.  When someone changes their appearance -- like Rich shaving off his beard and mustache -- it confounds me completely.

So I'm curious whether I'd be like the rest of the test subjects and have faster recognition times for faces than for non-face objects, or if perhaps my peculiar wiring means my brain weights all visual stimuli equally.  I'd be happy to volunteer to go to Japan to participate, if anyone wants to find out the answer badly enough to spot me for a plane ticket.

No?  Oh, well, perhaps that'll be the next phase of Martinsen et al.'s research.  I'm willing to wait.

Until then -- if I know you, and happen to run into you in the local café, keep in mind I may have no idea who you are.  It helps if you start the conversation with, "I'm _____" -- I'm not embarrassed by my odd neurological condition, and it's better than spending the day wondering who the person was who came up and gave me a hug and asked about my wife and kids and dogs and whatnot.

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Talking in your sleep

A little over a year ago, I decided to do something I've always wanted to do -- learn Japanese.

I've had a fascination with Japan since I was a kid.  My dad lived there for a while during the 1950s, and while he was there collected Japanese art and old vinyl records of Japanese folk and pop music, so I grew up surrounded by reminders of the culture.  As a result, I've always wanted to learn more about the country and its people and history, and -- one day, perhaps -- visit.

So in September of 2023 I signed up for Duolingo, and began to inch my way through learning the language.

[Image is in the Public Domain]

It's a challenge, to say the least.  Japanese usually shows up on lists of "the five most difficult languages to learn."  Not only are there the three different scripts you have to master in order to be literate, the grammatical structure is really different from English.  The trickiest part, at least thus far, is managing particles -- little words that follow nouns and indicate how they're being used in the sentence.  They're a bit like English prepositions, but there's a subtlety to them that is hard to grok.  Here's a simple example:

Watashi wa gozen juuji ni tokoshan de ane aimasu.

(I) (particle indicating the subject of the sentence) (A.M.) (ten o'clock) (particle indicating movement or time) (library) (particle indicating where something is happening) (my sister) (am meeting with) = "I am meeting my sister at ten A.M. at the library."

Get the particles wrong, and the sentence ends up somewhere between grammatically incorrect and completely incomprehensible.

So I'm coming along.  Slowly.  I have a reasonably good affinity for languages -- I grew up bilingual (English/French) and have a master's degree in linguistics -- but the hardest part for me is simply remembering the vocabulary.  The grammar patterns take some getting used to, but once I see how they work, they tend to stick.  The vocabulary, though?  Over and over again I'll run into a word, and I'm certain I've seen it before and at one point knew what it meant, and it will not come back to mind.  So I look it up...

... and then go, "Oh, of course.  Duh.  I knew that."

But according to a study this week out of the University of South Australia, apparently what I'm doing wrong is simple: I need more sleep.

Researchers in the Department of Neuroscience took 35 native English speakers and taught them "Mini-Pinyin" -- an invented pseudolanguage that has Mandarin Chinese vocabulary but English sentence structure.  (None of them had prior experience with Mandarin.)  They were sorted into two groups; the first learned the language in the morning and returned twelve hours later to be tested, and the second learned it in the evening, slept overnight in the lab, and were tested the following morning.

The second group did dramatically better than the first.  Significantly, during sleep their brains showed a higher-than-average level of brain wave patterns called slow oscillations and sleep spindles, that are thought to be connected with memory consolidation -- uploading short-term memories from the hippocampus into long-term storage in the cerebral cortex.  Your brain, in effect, talks in its sleep, routing information from one location to another.

"This coupling likely reflects the transfer of learned information from the hippocampus to the cortex, enhancing long-term memory storage," said Zachariah Cross, who co-authored the study.  "Post-sleep neural activity showed unique patterns of theta oscillations associated with cognitive control and memory consolidation, suggesting a strong link between sleep-induced brainwave co-ordination and learning outcomes."

So if you're taking a language class, or if -- like me -- you're just learning another language for your own entertainment, you're likely to have more success in retention if you study in the evening, and get a good night's sleep before you're called upon to use what you've learned.

Of course, many of us could use more sleep for a variety of other reasons.  Insomnia is a bear, and poor sleep is linked with a whole host of health-related woes.  But a nice benefit of dedicating yourself to getting better sleep duration and quality is an improvement in memory.

And hopefully for me, better scores on my Duolingo lessons.

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Dream songs

Last night I dreamed that our local mall had been converted into a giant used book store.  (Something I would entirely approve of.)  We were going to to go shopping ("we" being my wife, me, and our younger son, who lives in Houston but was apparently up for a visit) but we realized that a bunch of other family members were unexpectedly going to descend upon us, and for some reason we knew they were going to walk into our house without knocking, which our dogs would not appreciate, so we had to get home fast.  But while trying to get out of the mall we were hindered by a bunch of science-fiction cosplayers wearing silver body paint.

After that, it got kind of weird.

Dreams are a very peculiar thing, but they (and the REM sleep stage during which they occur) are ubiquitous in the brainier species of animals.  In fact, as I'm writing this, my puppy Jethro is curled up in his bed by my desk dreaming about something, because his paws are twitching and every once in a while he makes a very cute little "oof" noise.  But what would a puppy dream about?  Presumably the things that make up his waking life -- playing, chasing squirrels, swimming in our pond, eating his dinner.

You have to wonder if sometimes dogs, like humans, have weird dreams, and what they might make of them.

The function of dreaming is unknown, but what's certain is that it's necessary.  Suppress REM and dreaming, and the results are hallucinations and psychosis.  Aficionados of Star Trek: The Next Generation will no doubt remember the chilling scene in the episode "Night Terrors," where something is preventing the crew from experiencing REM sleep, and Dr. Crusher is in the makeshift morgue where the victims of a massacre are being examined -- and when she turns around, all the dead bodies are sitting up, still shrouded in their sheets.  She closes her eyes -- exhibiting far more bravery than I would have -- and says, "This is not real," and when she opens them, they're all lying back down again.

*shudder*

In any case, what brings up this topic today is far cheerier; a fascinating piece of research out of the University of Buenos Aires that looked at dreams in an animal we usually don't associate with them -- birds.  A team led by Gabriel Mindlin looked at a species of bird called the Great Kiskadee (Pitangus sulphuratus), a brightly-colored and vocal flycatcher found in much of Central and South America.  

Mindlin is one of the foremost experts in the physiology of bird song.  Birds have a unique apparatus called the syrinx that allows them to make some of the most complex vocalizations of any group of animals; not only can some (such as many wrens and thrushes) produce two or more tones at the same time, birds like parrots, mynahs, lyrebirds, and starlings are brilliant mimics and can imitate a variety of other sounds, including human speech.  (A lyrebird in a park in Australia learned to convincingly imitate a chainsaw, a car alarm, various cellphone ringtones, and a camera shutter.)

What Mindlin and his team did was to implant electrodes in the obliquus ventralis muscle, the main muscle birds use to control pitch and volume in vocalization, and also outfit some Great Kiskadees with devices to monitor their brain waves.  When the birds went into REM sleep, the researchers found that the OV muscle was contracting in exactly the way it does when the birds vocalize while awake.

The birds were singing silently in their sleep!

Singing in birds generally serves two purposes; mate attraction and territorial defense.  (As one of my AP Biology students put it, "they sing when they're mad or horny.")  It's more complicated than that -- science generally is -- but as a broad-brush explanation, it'll do.  Many species have different songs and calls for different purposes, each associated with a specific pattern of contractions and relaxation of the muscles in the syrinx.  Mindlin and his team used software capable of taking the muscle movements the electrodes detected and decoding them, determining what song the bird would have been producing if it was awake.  What they found was that the song their test subjects were dream-singing was one associated with marking out territories. 

"I felt great empathy imagining that solitary bird recreating a territorial dispute in its dream," Mindlin said.  "We have more in common with other species that we usually recognize."

So birds dream, and the content of their dreams is apparently -- just like Jethro -- taken from their own umwelt, the slice of sensory experience they engage with while they're awake.  (I wrote in more detail about the umwelt a while back, if you're curious.)  

On the other hand, how this accounts for my dream of silver-body-painted cosplayers in a mall filled with old books, I have no idea.

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