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.

****************************************

Voices and faces

I've blogged before about my difficulties with prosopagnosia (better known as "face blindness").  My ability to recognize faces is damn near nonexistent; when I do recognize someone, it's either through context or because I remember a specific feature or features (she's the woman with the blonde hair, green eyes, and lots of freckles; he's the guy with curly gray hair and a little scar on the forehead; and so forth).  This, of course, backfires badly when someone changes their appearance.  It's why I have an extremely poor track record of recognizing actors in unexpected roles, where makeup and costumes can dramatically change what distinctive features they may have.  I was absolutely flattened when I found out that Jim the Vampire in What We Do In the Shadows was played by none other than Mark Hamill, and that Peter Davison -- the Fifth Doctor in Doctor Who, a show I'm absolutely obsessed with -- played the suave French teacher Mr. Clayton in Miranda.

When I figure it out, it's often because the actor has a distinctive voice that even being in a different character can't quite hide.  I know British actress Zoë Wanamaker from three very different roles -- Quidditch instructor Madam Hooch in Harry Potter, the scheming Lady Cassandra in Doctor Who, and hapless mystery writer Ariadne Oliver in Agatha Christie's Poirot.  But in each role, she keeps a very distinct clipped, staccato cadence in her voice that, for me, is instantly recognizable.

So I'm above average at voice recognition, whereas I can't form mental images of faces at all.  Hell, sitting here right now, I can't picture my own face.  I know I have sandy blond hair, gray eyes, black plastic-framed glasses, and a narrow face, but it doesn't come together into any sort of image.  If I see a photograph of myself in a group shot, I often have a hard time finding myself, unless (1) I know where I was standing, (2) I recognize the shirt I'm wearing, or (3) there aren't any other skinny blond guys with glasses in the photo.

As I've mentioned before, to anyone local who is reading this; if I've walked past you on the streets of the village with a blank look, and not said hi, please don't take it personally.  I had no idea who you were, or that I'd ever seen you before.  I have no problem if you say hi and mention your name; in fact, I really appreciate it.  It's much less awkward to have someone say, "Hi, Gordon, it's Bill" than to have me standing there trying frantically to search for clues so I can figure out who I'm talking to, or worse, ignoring someone I actually like.

[Image licensed under the Creative Commons mikemacmarketing, Facial Recognition22, CC BY 2.0]

The reason this topic comes up is because of a puzzling piece of research in the Journal of Neurophysiology this week, that looked at the brain firing patterns in people when they heard famous people speaking (they used the voices of Barack Obama, George W. Bush, and Bill Clinton).  The test subjects were epileptic -- such studies often use epileptic volunteers who already have electrodes implanted in their brains to monitor their seizures, and the same technology can be used to study their other brain responses -- but were not prosopagnosic. 

The reason I say the research was puzzling is they found that very same part of the brain that seems to be miswired in prosopagnosia, the fusiform gyrus of the basal temporal lobe, was extremely active during the volunteers' attempts to identify voices.  Put a different way, the face-responsive sites in the brain are also involved with vocal recognition.

How, then, does one of those responses go so badly wrong in people like me, and the other one is largely unimpaired?

The current research is preliminary; identifying the site in the brain where a response occurs is only the first step toward figuring out what exact pathway the firing sequence takes or how it's mediated.  The parts of the brain have a remarkable degree of functional overlap, and this is hardly the only example of two seemingly related abilities working in very different ways.  

In fact, I can think of another instance of this phenomenon from my own experience.  I have near-perfect recall for music; my wife calls it my "superpower."  I hear a melody a couple of times, and I pretty much have it for life, and if it's in the range of my instrument, I can play it for you.  My ability to remember text, though, is mediocre at best, the main reason I gave up on doing community theater -- memorizing lines was painfully difficult for me.  It's hard to imagine why two different examples of recall involving sound would be so dramatically different, but they are.

So here, there's obviously something going on in the fusiform gyrus in face-blind individuals that interferes with visual recognition and leaves vocal recognition largely unaffected.  It'd be interesting to look at the electrocorticography for prosopagnosic volunteers.  (To use the technique in the paper, though, they'd have to find face-blind people who were also epileptic and had surgical electrode implants, which would be a small subset of a small subset of a small subset of humanity.  Kind of limits the possibilities for volunteers.)

In any case, it's interesting research, and I'm curious to see where it will lead.  We're only at the beginning of understanding how our own brains work, and the next twenty years should see some significant strides toward the maxim engraved on the walls of the temple of the Oracle of Delphi -- γνῶθι σεαυτόν (know thyself).

****************************************

Brains, mysticism, and melting faces

"Well, I saw it. I saw it with my own eyes."

You hear that a lot, in claims of the paranormal.   I was just sitting there, in my room, and the ghost floated in through the wall.   I was outside at night, and I saw the UFO zoom across the sky.  I was at the lake, and I saw ripples in the water, and a dinosaur's head poked out and looked at me.

In a court of law, "eyewitness testimony" is considered one of the strongest pieces of evidence, and yet time and again experimental science has shown that your sensory apparatus and your memory are flawed and unreliable.   It doesn't take much to confuse your perception -- witness how persuasive many optical illusions are -- and if you couple that with how easily things get muddled in your memory, it's no wonder that when eyewitness claims of the paranormal are presented to scientists, most scientists say, "Sorry. We need more than that."

A fascinating study published in the Journal of Neuroscience has put another nail in the coffin of our perceptual integrative systems, showing how easy it is to trigger someone to see something that isn't there in a completely convincing way.  Ron Blackwell, an epileptic, was in the hospital having tests done to see if a bit of his brain that was causing his seizures could be safely removed.  As part of the pre-surgical tests at Stanford University Hospital, his doctor, Dr. Josef Parvizi, had placed a strip of electrodes across his fusiform gyrus, a structure in the temporal lobe of the cerebrum.  And when the electrodes were activated, Blackwell saw Dr. Parvizi's face melt.

[image courtesy of the Wikimedia Commons]

"You just turned into somebody else," Blackwell said.  "Your face metamorphosed.  Your nose got saggy, went to the left.  You almost looked like somebody I'd seen before, but somebody different."  He added, rather unnecessarily, "That was a trip."

This study has three interesting outcomes, as far as I'm concerned.

First, it shows that the fusiform gyrus has something to do with facial recognition.  I'm personally interested in this, because as I've described before in Skeptophilia, I have a peculiar inability to recall faces.  I don't have the complete prosopagnosia that people like the late great science writer Oliver Sacks had -- where he didn't even recognize his own face in a mirror -- but the fact remains that I can see a person I've met many times before in an unfamiliar place or circumstance, and literally have no idea if I've ever seen them before.  However -- and this is relevant to Parvizi's study -- other human features, such as stance, gait, and voice, I find easily and instantly recognizable.  And indeed, Blackwell's experience of seeing his doctor's face morph left other body parts intact, and even while the electrodes were activated, Blackwell knew that Dr. Parvizi's body and hands were "his."  So it seems that what psychologists have claimed -- that we have a dedicated module devoted solely to facial recognition -- is correct, and this study has apparently pinpointed its location.

Second, this further supports a point I've made many times, which is that if you fool your brain, that's what you perceive.  Suppose Blackwell's experience had occurred a different way; suppose his fusiform gyrus had been stimulated by one of his seizures, away from a hospital, away from anyone who could immediately reassure him that what he was seeing wasn't real, with no one there who could simply turn the electrodes off and make the illusion vanish.  Is it any wonder that some people report absolutely convincing, and bizarre, visions of the paranormal?  If your brain firing pattern goes awry -- for whatever reason -- you will perceive reality abnormally.  And if you are already primed to accept the testimony of your eyes, you very likely will interpret what you saw as some sidestep into the spirit world.  Most importantly, your vehement claims that what you saw was real cannot be accepted into evidence by science. Ockham's Razor demands that we accept the simpler explanation, that requires fewer ad hoc assumptions, which is (sorry) that you simply had an aberrant firing pattern occur in your brain.

Third, this study has significant bearing on the stories of people who claim to have had "spiritual visions" while under the influence of psychoactive drugs.  One in particular, DMT (dimethyltryptamine), present in such ritual concoctions as ayahuasca, is supposed to create a "window into the divine."  A number of writers, particularly Terence McKenna and Rick Strassman (the latter wrote a book called DMT: The Spirit Molecule), claim that DMT is allowing you to see and communicate with real entities that are always there, but which only the drug allows you to experience.  Consider McKenna's account of his first experience with the chemical:

So I did it and...there was a something, like a flower, like a chrysanthemum in orange and yellow that was sort of spinning, spinning, and then it was like I was pushed from behind and I fell through the chrysanthemum into another place that didn't seem like a state of mind, it seemed like another place.  And what was going on in this place aside from the tastefully soffited indirect lighting, and the crawling geometric hallucinations along the domed walls, what was happening was that there were a lot of beings in there, what I call self-transforming machine elves.  Sort of like jewelled basketballs all dribbling their way toward me.  And if they'd had faces they would have been grinning, but they didn't have faces.  And they assured me that they loved me and they told me not to be amazed; not to give way to astonishment.

A generation earlier, Carlos Castañeda recounted similar sorts of experiences after ingesting datura root and psilocybe mushrooms, and like McKenna and Strassman, Castañeda was convinced that what he was seeing was absolutely real, more real in fact than the ordinary world around us.

My response, predictably, is: of course you saw weird stuff, and thought it was real.  What did you expect?  You monkey around with your brain chemistry, and you will obviously foul up your perceptual apparatus and your ability to integrate what's being observed.  It's no more surprising that this happens than it would be if you spilled a cup of coffee on your computer, and it proceeded to behave abnormally.  If you short out your neural circuitry, either electrically (as Parvizi did) or chemically (as McKenna and others did), it should come as no shock that things don't work right.  And those altered perceptions are hardly evidence of the existence of a mystical world.

In any case, Parvizi's accidental discovery is a fascinating one, and will have wide-reaching effects on the study of perceptual neuroscience.  All of which supports what a friend of mine, a retired Cornell University professor of human genetics, once told me: the 21st century will be the century of the brain.  We are, she said, at a point of our understanding of how the brain works that corresponds to where geneticists were in 1915 -- we can see some of the pieces, but have no idea how the whole system fits together.  Soon, she predicts, we will begin to put together the underlying mechanism.  And at that point, we will be starting to develop a complete picture of how our most complex organ actually works.

Brains, mysticism, and melting faces

"Well, I saw it.  I saw it with my own eyes."

You hear that a lot, in claims of the paranormal.  I was just sitting there, in my room, and the ghost floated in through the wall.  I was outside at night, and I saw the UFO zoom across the sky.  I was at the lake, and I saw ripples in the water, and a dinosaur's head poked out and looked at me.

In a court of law, "eyewitness testimony" is considered one of the strongest pieces of evidence, and yet time and again experimental science has shown that your sensory apparatus and your memory are flawed and unreliable.  It doesn't take much to confuse your perception -- witness how persuasive many optical illusions are -- and if you couple that with how easily things get muddled in your memory, it's no wonder that when eyewitness claims of the paranormal are presented to scientists, most scientists say, "Sorry.  We need more than that."

Just last week, a study published in the Journal of Neuroscience put another nail in the coffin of our perceptual integrative systems, showing how easy it is to trigger someone to see something that isn't there in a completely convincing way.  [Source]  Ron Blackwell, an epileptic, was in the hospital having tests done to see if a bit of his brain that was causing his seizures could be safely removed.  As part of the pre-surgical tests at Stanford University Hospital, his doctor, Dr. Josef Parvizi, had placed a strip of electrodes across his fusiform gyrus, a structure in the temporal lobe of the cerebrum.  And when the electrodes were activated, Blackwell saw Dr. Parvizi's face melt.

"You just turned into somebody else," Blackwell said. "Your face metamorphosed.  Your nose got saggy, went to the left.  You almost looked like somebody I'd seen before, but somebody different."  He added, rather unnecessarily, "That was a trip."

This study has three interesting outcomes, as far as I'm concerned.

First, it shows that the fusiform gyrus has something to do with facial recognition.  I'm personally interested in this, because as I've described before in Skeptophilia, I have a peculiar inability to recognize faces.  I don't have the complete prosopagnosia that people like the eminent science writer Oliver Sacks has -- where he doesn't even recognize his own face in a mirror -- but the fact remains that I can see a person I've met many times before in an unfamiliar place or circumstance, and literally have no idea if I've ever seen them before.  However -- and this is relevant to Parvizi's study -- other human features, such as stance, gait, and voice, I find easily and instantly recognizable.  And indeed, Blackwell's experience of seeing his doctor's face morph left other body parts intact, and even while the electrodes were activated, Blackwell knew that Dr. Parvizi's body and hands were "his."  So it seems that what psychologists have claimed -- that we have a dedicated module devoted solely to facial recognition -- is correct, and this study has apparently pinpointed its location.

Second, this further supports a point I've made many times, which is that if you fool your brain, that's what you perceive.  Suppose Blackwell's experience had occurred a different way; suppose his fusiform gyrus had been stimulated by one of his seizures, away from a hospital, away from anyone who could immediately reassure him that what he was seeing wasn't real, with no one there who could simply turn the electrodes off and make the illusion vanish.  Is it any wonder that some people report absolutely convincing, and bizarre, visions of the paranormal?  If your brain firing pattern goes awry -- for whatever reason -- you will perceive reality abnormally.  And if you are already primed to accept the testimony of your eyes, you very likely will interpret what you saw as some sidestep into the spirit world.  Most importantly, your vehement claims that what you saw was real cannot be accepted into evidence by science.  Ockham's Razor demands that we accept the simpler explanation, that requires fewer ad hoc assumptions, which is (sorry) that you simply had an aberrant firing pattern occur in your brain.

Third, this study has significant bearing on the stories of people who claim to have had "spiritual visions" while under the influence of psychoactive drugs.  One in particular, DMT (dimethyltryptamine), present in such ritual concoctions as ayahuasca, is supposed to create a "window into the divine."  A number of writers, particularly Terence McKenna and Rick Strassman (the latter wrote a book called DMT: The Spirit Molecule), claim that DMT is allowing you to see and communicate with real entities that are always there, but which only the drug allows you to experience.  Consider McKenna's account of his first experience with the chemical:

So I did it and...there was a something, like a flower, like a chrysanthemum in orange and yellow that was sort of spinning, spinning, and then it was like I was pushed from behind and I fell through the chrysanthemum into another place that didn't seem like a state of mind, it seemed like another place.  And what was going on in this place aside from the tastefully soffited indirect lighting, and the crawling geometric hallucinations along the domed walls, what was happening was that there were a lot of beings in there, what I call self-transforming machine elves.  Sort of like jewelled basketballs all dribbling their way toward me.  And if they'd had faces they would have been grinning, but they didn't have faces.  And they assured me that they loved me and they told me not to be amazed; not to give way to astonishment.

A generation earlier, Carlos Castañeda recounted similar sorts of experiences after ingesting datura root and psilocybe mushrooms, and like McKenna and Strassman, Castañeda was convinced that what he was seeing was absolutely real, more real in fact than the ordinary world around us.

My response, predictably, is: of course you saw weird stuff, and thought it was real.  What did you expect?  You monkey around with your brain chemistry, and you will obviously foul up your perceptual apparatus, and your ability to integrate what's being observed.  It's no more surprising that this happens than it would be if you spilled a cup of coffee on your computer, and it proceeded to behave abnormally.  If you short out your neural circuitry, either electrically (as Parvizi did) or chemically (as McKenna and others did), it should come as no shock that things don't work right.  And those altered perceptions are hardly evidence of the existence of a mystical world.

In any case, Parvizi's accidental discovery is a fascinating one, and will have wide-reaching effects on the study of perceptual neuroscience.  All of which supports what a friend of mine, a retired Cornell University professor of human genetics, once told me: the 21st century will be the century of the brain.  We are, she said, at a point of our understanding of how the brain works that corresponds to where geneticists were in 1912 -- we can see some of the pieces, but have no idea how the whole system fits together.  Soon, she predicts, we will begin to put together the underlying mechanism -- and at that point, we will be starting to develop a complete picture of how our most complex organ actually works.