EEG Studies of Social Perception, Dr. James McPartland

EEG Studies of Social Perception, Dr. James McPartland


So I am the guy who was sat over there for the last four weeks who know has the pleasure of
talking to you about what I do. So I’m an assistant professor here at the Child Study Center and I’m the associate director of the Developmental electrophysiology laboratory,
which is run by Linda Mays and we kinda of pool our resources cause we all apply the same methods to study child development, both typical and atypical development. And we also all are kind of interested in social development for different kinds of reasons. And I should also acknowledge Michael Crowley, who is the other associate director of the DEL. So when we start a talk like this in the medical school, we make disclosures, we present everything that gives us a bias. So there’s the financial biases. These are the people who fund the research that we do. So I get money to do my research from a couple of different government institutes and I will soon from NARSAD. And I also get money from book sales. And then in this particular instance I want
to disclose a non-financial conflict of interest because we, all the presenters, you’ve heard us kind of gripe about this, it’s weird for us. What we do as clinical psychologists is show lots of pictures of people and we show you videos of people and they make things interesting. They keep the people who are listening to you awake, which is something that we all like. We can’t do that for this, but for me it’s a different situation because
every moment that I am speaking to an audience and showing them pictures of people who are
not my children, I am experiencing internal tension. So now I have the nice circumstance, where I have only the choice to show you pictures of people who’s right to consent I control. And so you’ll be seeing lots of Nora and Agnus in the next hour or so. So what I’m going to talk about today is the research that I have been doing here. I have been here since
2004. I first came here as a, as a clinical intern. I’m a clinical psychologist
and then I did a post-doc. And then I’ve been on the research faculty and the regular
faculty, since then. So I, I am very interesting autism and the way people
with autism process information because I think of autism as a social disorder. I am very interested in the way they process social information. And one of the best ways to study social information
processing is with faces. So we’re going to start off talking some about behavioral and brain specialization for faces. And then I’m going to talk a little bit about electrophysiology, about the method of electrophysiology because it’s not familiar to everybody and some of the things about it are a little idiosyncratic. I’m going to talk about face perception as a tool to understand autism and social development in autism and whether the problems that we see in autism are better
explained as a, a general information processing problem or some kind of specific problem, a specific problem to social information. And then I’m going to talk about some of the work
that’s going on now and some of the things that we have in store. And please do interrupt just because the cameras are rolling doesn’t
mean that you can’t ask questions, so please do. I, maybe I’ll try to be unclear so you have to ask questions. So when we think about autism, and this should all be familiar to you now, and when we think about autism as problem in three areas: so social problems, problems with communication and that can be lots of different kinds of problems with
communication. It could mean that you just don’t talk. It could mean that you have lots of language, but have problems communicating
with people, but mostly resolving, revolving around social communication. And then a third category that’s a, a, a lot more nebulous and less well defined. We describe this as rigid, repetitive behaviors
and interests. And this can be anything ranging from repetitive motor movements like hand flapping or being really insistent on a particular schedule or particular routine, so those kinds of things, so. And when we have problems in all those areas, we describe them as autism spectrum disorders. One of things that’s really crucial to think about when you think about autism is that it happens in a developing child. So autism isn’t just something that happens, right. It’s something that a person is most likely
born with, but then they carry that through them, through, carry that with them as they, they move through the world. And in that respect autism shapes the world the person lives in. So when whatever is different about their brain when they’re born, it’s also affected by a very different world that they live in. So there’s the kind of primary things that first shape the brain, but then there’s a secondary things that a person experiences as they move through
the world, as a person with autism. So if we think about typical social development kind of representing this course. So we come into the world really attuned to people. And I’m going to talk about, I know you are, you all are going to have a face, face development overload because Kasha talked about some of it already, but I’ll try to talk about some of
the facts that she, she didn’t touch upon because these are some of the things I think are really coolest about human development. But I’ll talk about, we cut, how we come into the world really paying
close attention to people and we remain that way. For most of us people are really what make
the world go around and we spend our lives thinking and learning
about people. We become social experts, but we can think about people, well, people with autism, for example, charting a different course, so kind of becoming expert in other things, so paying attention to things besides people, learning about those
things, becoming experts other things. What’s important to think about, about this kind of way of understanding autism, if we’re not saying the this is a brain that can’t do certain kinds of things, we’re saying it’s a brain that is paying attention
to the wrong kinds of information, which is a crucial distinction when we think about
the different kinds of theories that people have put forward to explain autism they can kind of grossly fall into two categories: the idea there’s something wrong with social
information processing or the idea that this is a brain that can’t handle the nature of processing of things that happen to be social. And by that I mean, for example, complex information, the idea that people with autism only have trouble
with social information because it’s complex versus there being something uniquely social about it. And so when we look at it this way we’re saying that this is a brain that can do many sophisticated,
many complex things, it just can’t do them with social information. And so, as a, a person is interested in development, when
we look at these, these pathways, right, we think of this person getting older at
they move along and we want to understand how we can trace it further back, right. If we think about this person the further they get down here the harder time they’re having with many of the things
that really matter in the world cause a lot of the things right now that matter in the world from having friends to, to checking out of a super market involve people and so one of the ways we study this is with faces because we can learn so much about faces very early in life and we can apply it throughout the lifespan. So it’s a good way for us as people interested in child development to try to get down to the brass tacks in terms
of where things start both in healthy social development and in terms of where things go awry in atypical social development. So let’s talk some about faces in typical social development. So we know that faces are probably thee
first way, I guess sound too, and some of my colleagues have interesting theories about the way sound could shape social development even within the womb, but conventionally faces are one of the first ways that we learn to interact with other people, that we about other people. and we also know a lot about faces, so developmental psychologists, cognitive neuro-scientists, neurologists have all done a lot of great
research to help us understand the way people approach faces, both in early infancy and throughout the lifespan. So it’s a really nice comparison for autism, which is we think it has something to do with social, social interaction that we think affects us very early
in life and that we think carries us, carries through lifespan, but we know very little about in terms of the neuro bases. And so faces are a nice way to kind of tap in to those areas that are, that have yet to be explained
in autism. So, just some of the, I guess I wouldn’t even call them facts, but you can call them factoids about faces, bless you, is that very early in life, so infants nine minutes old are more likely to look at faces or things that are, even things that are just like faces. So if you take a schematic face, just with two squares on the top and and one square on the bottom, kind of like two eyes and a mouth, but not even the right shape, just the configuration, infants are going to look at that more than other things. They are going to track it further. So if you move one across an infant’s field of vision, they’re going to follow it further. And this is compared to even an upside down one or a bull’s eye, you can take lots of things that you might be interesting, that you might think would be interesting to infants,
all the Fisher Price toys. Oh we’re going to have to take that out of the youtube cut, all the Fisher Price toys and a Toys”R”Us are not as interesting to most infants as, as faces. We also know that babies are more likely to smile at human faces. This is my older daughter doing her best pirate impression as a five-week-old. We know that, that again infants seem to enjoy looking
at faces, which is a great tool. So how many people in this room have ever interacted
with a really small baby, say a five-week-old baby? So if you do something to that baby and that baby smiles at you, what do you do? I’m sorry. You smile back. You do it again. I’ve spent over the past three years tremendous amounts
of time making stupid faces and stupid sounds to make this happen again. And so here is this little helpless baby that has this one tool they can use that can then control the behavior of an adult very effectively, right.
So what a great way to, to draw the kind of information that we need
to develop. If people talking to us and people smiling at us and making silly sounds it’s going to, what’s going to help us grow. It’s pretty amazing that human infants come into the world able to elicit that information from their environment. So by the second day very young children are able to recognize the
face of their mother and these have been very elegant studies controlling for whether a person has also
just given birth, so it’s not new motherness they’re recognizing. It’s not the scent of their mother they’re recognizing. It’s not her blondness or her burnettness or her
blue-eyed-ness. They’re recognizing the face of their mother by the second day of life. And in one of my, my favorite studies of all time, this is a study done by Andy Meltzoff who is at the University of Washington, who I was fortunate to study with as a
graduate student. And what Andy did was he partnered with a maternity ward in a hospital in Seattle and he found some parents who were apparently very, very motivated to help
science and they got his beeper number and when the baby was born and he was beeped and whether it was noon or whether it was midnight or whether it was three a.m. or nine a.m., Andy would zip down to the hospital and
that newborn baby would be put in a, a baby carrier and Andy would hover over the baby with a video camera behind him filming the baby but not filming Andy and then Andy would do things to the baby. He would stick out his tongue. He would pucker his lips. He would open his mouth, all while the video camera is recording the baby. So then he would take these videotapes back
to his research assistants and they would code what the baby’s face was doing and sure enough you were able to predict what face Andy had been making by looking at the baby. So, the youngest kids that they saw this happening
in were kids who were forty-two minutes old. So what’s so remarkable about this is that when we think about kind of the cliche of nature
versus nurture, there hasn’t been a lot of nurturing that’s happened in forty-two minutes, right. So these are kids who haven’t had a ton of time to learn about their own face. They haven’t had a ton of time to learn about other people’s
faces and yet they’re able to see what’s happening
there, understand what’s, what that is, what’s there is what I’ve got here and what that is doing I can do. And Andy really takes this as the, the basis for all social interaction, the idea he calls the “Like Me” hypothesis, the idea that children are born with a, with an internal and intramodal, and, and intramodal map, so that they can kind of map on what they see to their sense of their body. And he thinks that that’s from where social interaction
emerges. So then we also know that, we theorize the face processing also gives us a foundation for much more sophisticated social interaction skills. So does everyone know what theory of mind is? Who can tell me what theory of mind is? That is the idea that others have their own ideas and beliefs. Exactly. Right, that that other people have their own intentions, their own wants, their own needs, their own beliefs. And so, one of the ideas for the development of a
theory of mind and, and Simon Baron Cohen, who’s a very productive autism researcher has written eloquently about this, is that under, understanding other people’s faces and understanding other people’s eyes is the first way we can learn about other
people’s intentions. And by understanding other people’s intentions, we can then build the idea that their intentions aren’t necessarily the same as ours and that’s the basis of a theory of mind. So we’ve talked about these kind of early, these aspects of early development that are really precocious. We’re very good with faces before we’re very good with many other things and as we develop we see that the human brain has special ways of handling faces and this is evident through two lines of evidence. One line of evidence is processing strategies. So behavioral studies that I’ll talk about show us that we seem to handle information in a face differently than we handle most other kinds of information. And also brain studies through, through autopsies to intracranial recordings, through FMRI, and through electrophysiological studies, on the outside of the scalp we also find they’re special brain regions to handle faces. In terms of processing strategies, two things that are really robust findings in faces are the inversion effect and decomposition effect. So the inversion effect is really simple, when we turn a face upside down, it’s much harder to recognize. We’re all very good at recognizing faces. And it’s pretty remarkable when you think about. Right, so
so here’s a room full of people and you all look completely distinct to me, but it, but you also all have two eyes, a nose, and a mouth. I apologize if I’m mistaken about anybody. I’m assuming. But you, you all have this same set of features on your face, right. We all are kind of the same and yet we look totally different. If you think about carrots or apples, right, or monkeys, we have monkey researchers in the
room/ I have tried. I have done experiments where I use monkey faces, monkey faces are at least as valuable as ours, right. They’ve got different hair that might even make it a, a, better clue about telling monkeys apart, but I can’t tell them apart. Right, we’re really good at telling apart these things, these faces that are all pretty
similar, but we turn them upside down and we’re not much better at telling them apart than any, than anything else. Then there’s also a finding called the decomposition
effect, so even though we can know people’s faces very well, we’re very bad at recognizing facial features outside of the context of a face. So even though this is my younger daughter, Aggie, so even though I recognize her face very well, you know, pay, taking her eyes or her nose and putting them
outside the context of her face with another baby’s nose or eyes I’m not going do nearly as well as I would with the entire face. And so what these kinds of findings, the idea that faces upside down or faces in pieces are
much harder to process, it tells us that we might be encoding the information
in the face in a different way. So we think that most objects we encode in a piecemeal way, so kind of the idea that a monkey face or an apple or a carrot is really just the sum of its parts, but a human face isn’t. A human face is encoded as a whole using configural processing strategy. So we learn faces as a unit, recognizing their features with respect to one another. So the idea is that this is a really distinct processing strategy that we apply selectively to human faces and that we, we learn to use over time, that as we become experts in faces we start to apply this processing strategy. We also know that we have special parts of the brain to process faces. And the first evidence for this came from
the work of a neurologist and he found patients who could lose the ability to recognize individual faces, while still being fine at recognizing other things. So if they go to get their keys, they’re not going to pick up their co-worker’s keys, but they go to pick up their wife, they might pick-up their co-worker’s wife. So he, he, he looked at the brains of these people and he found that almost without variation this disorder was secondary to damage to certain parts of the cortex, part of the inferotemporal cortex. And most of the time it was on the right, sometimes it could be on both, but most of the time this was on the right. And so this was the first clue. Okay,
so maybe if people who get this part of the brain damaged lose this skill, maybe this part of the brain has something to do with the application of this skill. And so now we have a lot more elegant ways to
look at the brains and you’ll hear, I believe, next week from my colleague Kevin Pelphrey, who applies the method that’s named on this slide, Functional Magnetic Resonance Imaging. And what Functional Magnetic Resonance Imaging done, does, or FMRI, is lets us look at blood flow within the brain. So it tells us, when we have a person performing the task inside a FMRI magnet, we have a good chance sense of to where in their
brain blood is flowing and that gives a very good sense of the spatial resolution
of activity, so where in the brain things happen. So, in 1997, a paper was published, a very famous paper, a seminal work, the third author of the paper some of you may recognize. He is now faculty member in the department of psychology, Marvin Chun. And if I was allowed to show copyrighted information you would see a picture
of Marvin from that journal article with a little Fusiform Gyrus lighting up right next to him, but we can’t so we’ll just say, so instead this is another excuse to put a picture of my daughter. There she’s modeling a neuro-scientist-in-training t-shirt from a mentor of mine at, at Harvard, Chuck Nelson, who has done a lot of pioneering work in, in understanding infant brain activity using ERP. So, what they found from using FMRI is if you show people faces compared to many, many things, animal faces, places, hands, you saw this part of the brain selectively activated, so it’s the part of the brain called the Fusiform Gyrus, which they call the Fusiform Face Area. There’s a more nuanced story and than, than just the Fusiform Face Area that I’ll get into in a little bit. But now let’s talk a little bit about electrophysiology. I think that electrophysiology is
a little mysterious than some of the other methods that we use to study, to study brains, and to, to look at people’s behavior and things like
that. So when we talk about electrophysiology, we often talk about ERP, so ERP stands for Event- related Potential. Have you all heard of EEG before? So maybe you’ve heard about it because EEGs are used to clinically, so EEG is electroencephalaogram and that’s just a recording of the electrical activity that your brain produces. So all the time when we’re doing anything, as long as we’re alive our brains are producing a small amount of
electricity. And it’s noisy, lots of different things
are happening in that electricity. If I just show you a face and look at the electricity your brain is making, it’s going to be kind of confusing, and if I show you a second face, it might not look exactly like what we saw in
response to the first face, but what we can do is if we show you many, many faces, eventually what is the electrical activity that is
elicited specifically by that face is going to kind of emerge from the noise, right. So if I do the same thing many times, sixty times, a hundred times, eventually if I collapse all of those trials together and I average them, I’m going to get a decent enough to noise ratio that I will see the electrical truth. I’ll see the activity that is happening in response to this discrete event, this happening that is related to this event, this event-related potential. ERPs don’t reflect the refiring, the firing of a
single neuron, they reflect the firing of many, many neurons that are firing in synchrony. So it really gives us a window and a particular
time of brain activit.y The nice thing about ERPs is their timing. So I, I stressed before with FMRI that we get a very good sense of where in
the brain things happens, with an ERP we don’t. I think about ERPs almost like shadows, electrical shadows on the scalp. And so you know that a shadow has been cast and you can show two different kinds of images
and see whether the shadows are the same or different, but you really don’t know exactly where the light source is creating that shadow
or what exactly the size of the object creating that shadow is. So we have a very difficult time knowing exactly
where in the brain ERPs come from, but we can really pinpoint in a way that we can’t with other neuro-imaging methods the timing. So ERPs gives us millisecond resolution to understand differences in cognitive events in the brain. So the, the resolution of ERPs parallels
the resolution of actual brain processes. So we can get a sense of things like the timing of a response that we can’t get from other methods. Now when I say that we, we can’t really tell where in the brain things are coming from with ERP, that’s kind of a debated point. That’s certainly the conservative stance to take. As an ERP researcher, maybe I should come out kind of fighting a little bit and take a, a more aggressive stance because what we can do is a process called source localization, so if I have many, many points, data points on the scalp and I can measure the electrical activity of all of them, I can kind of test hypotheses. I can say well if I see a pattern of activity that is happening in response
to a face, I know for FMRI studies that Fusiform Gyrus is involved in faces, so I can kind of create a seed in that Fusiform Gyrus and see if electricity, if electrical activity propagating from there could potentially result in the pattern of activity I see on the scalp. So we can do that and that’s called source localization analysis and I’ll actually show you an example of
that later today. The problem is, is the inverse problem, and the inverse problem is really simply that for any given, because there could be more
than one source of electrical activity in the brain, for any given scalp distribution, there could be an infinite number of potential solutions inside the brain. So, we can get a sense of where things come from with a, with ERP where things come from in the brain, but it’s really not as, as robust as FMRI. And really we’re increasing starting to think
about them as complementary tools. Now we have the technology to be able to record ERPs inside FMRI magnets, so that we can look at both the timing and the, and the places in the brain where things happen. So what does an ERP look like? So this is a, a Geodesics sensor net. Im going to give lots of attention to the creators of this net because I’m using pictures from their
website. So this is electrical Geodesics. The director John Tupper is a close collaborator of ours. This is actually an updated version that they sent me several years ago, but basically the idea is you have many electrodes. This is a two hundred and fifty six electrode net. And so you see you could, all of those white things that
you see are plastic pedestals. Inside each one of those plastic pedestals, and you can kind of see it right there, is a small sponge. Inside that sponge is a small electrical censor, which is connected by all of these wires to an amplifier to boast the signal because it’s a really small signal, that’s why we don’t shock each other. And then that amplifier feeds to a computer that records the brain activity. The reason, who can guess, maybe it’s not a guess if you’ve been involved with an EEG, why would we want to have sponges in there? And I’ll give you a clue. Why don’t you wade in the surf during a lightning storm? Exactly right. And what kind of water best conducts electricity? I’ll give you another hint. We might, we would wade in a lake before we waded in the ocean in a lightning storm. Exactly. So we actually, so we soak all of these sponges in an electrolite solution. It’s actually potassium chloride not sodium chloride. And that helps pick up the electricity from the scalp. So this is a really nice technology. There’s different ways to record EEG. There’s the traditional way is to kind of scratch the scalp a little bit with like a needle and use a, an abrasive gel that kind of creates the contact. But this is a really nice solution, especially if you’re working with babies or has anybody, anybody familiar with the developmental disability sometimes associated with sensory sensitivities? Like throughout, let’s say hypothetically you’re sitting in a class about autism, right. So it’s a nicer solution for working with people with autism because it’s a little bit easier to tolerate than scratching someone’s scalp and using the gel base? The way you apply it is you just kind of stretch it
over a person’s head. And here’s a, a close up of what those electrodes look like and this
is from the newer version from what we call hydro cell net, which just have smaller sponges, sponges embedded in little cups that actually help things not dry out so fast, so so you can do longer experiments. So what’s, any questions about the technique or this hat or any of this stuff or any questions about anything I’ve talked about so far? Well how, you mean, how do you the experiment? It’s a really good question. Another woman? And to, well let me compound your question with a question. Professor McPartland, how do they do it when infants have such poor visual
acuity? And the answer is they probably do it with configuration, so infants see low spacial frequencies better, so they’re going to kind of see the dark spots. And so that’s even remarkable, right, it’s not like they’re saying my mom’s the one with the really salient crow’s feet. No, they’re recognizing my mom’s the one with
this configuration of eyes, nose, and mouth. My question is when do they encode the face? So obviously they have a test phase in this study? So do they encode it? You know, when do they encode the face before this time? It’s a good question. We couldn’t be sure, right. We, my guess would be, and this is coming both less from being a, a cognitive neuro-scientist, a child psychologist, a person who studies human development, and more from a father, is that when a baby is born and you put them to the breast to nurse or even if you don’t breast feed, you give them bottle that infant gazes so intently at a person’s face that, that’s probably how. And it’s really, I don’t, I don’t know the different theories
about what exactly, exactly happens, is happening in the brains of babies in the moments when they are born, but little babies are, can be quite ornery, but they’re generally pretty peaceful. It’s this period of kind of they call it, what do they, wakeful alertness right after infants are born, when they kind of look at everything and take everything in, so who knows, maybe they’re. But it’s a good question, but it’s not, it’s not known. We could look at it, I mean, we can use ERPs on very very early babies so who knows, I mean, you could look at response to a what’s happen, what’s happening and I guess
it would be pretty hard to look at because you need multiple trials, but we could record their response rates per. It could also be some kind of pairing right, so even though an infant’s seeing his or her mother’s face for the very first time, time, they’ve been hearing the voice for a long time, right. And so maybe it’s hearing, seeing this come with this familiar voice. But, it’s a good question. Any other questions? I’m so happy we got a question, right, mid-lecture. This is banner day for psychology 350. Any other questions, okay. So the nice thing about ERPs is really all you have to be able to do is to be able tolerate wearing a hat. So we can put this hat on very, very young
babies, and infants children, adults. When working with people with autism, we can put this hat on people with autism, who are much, much smarter than anybody in this room. We can also put this on people with autism who don’t have any language or who have ostensible cognitive impairments. So it really gives us a, it’s widely applicable in terms of studying brain function. So when we think about the way we do an ERP is we have a person wear this hat they sit in a chair in front of a, a TV monitor. It doesn’t have to be a TV monitor, we a, you can also do ERPs to auditory stimuli. In fact people have actually to try to, so I’ll talk about face perception today and all the faces I show you are, they’re not real faces. They’re pictures of faces on a computer screen. So people have reasoned, well, how can we be sure that people will treat the face on the computer screen the same way as a regular face. People have actually done experiments where they have a, a person behind, what’s it called, piezoelectric piece of glass, so when you turn charge, you can make the glass opaque or transparent. So they’ve actually done ERPs to real faces, but here we do ERPs to, to pictures on a computer screen. You make the same thing happen many, many, many times. One thing that’s really important about ERPs is making sure that you have some measure of a person’s attention because what if, you know, I do a study of face processing in people with autism and typically developing peers and I see differences, but what if the people with autism were all looking out the window during the course of the experiment, right. That could be the reason for different brain activity. And so it’s a very important you have some kind
of measure that person is paying attention. And so these are, these are images taken from
the website of the Locke lab led by Steven Locke, who’s really one of the pioneers of ERP, if any of you, of you are interested in, in reading more about the basis of ERP, I’d be happy to lend you his very excellent introductory books. What you can see is you have sort of ongoing EEG and then we have things that happen. So if you see here this is the first, let’s say, you know, he just calls it stimulus, but let’s say it’s the first face and then we see a response and then the second face and then we see a
response. And then so on to the nth face. And we see lots of different responses and then what we can do is take all of those responses and average them together. So if you see this one, this one, this one, they have some commonalities, right. For all of
them have some kind of dip here. There’s something else over here and then there’s something else over here. But when we average them all the different kinds of pieces of noise because lots of things are happening. You might be
blinking. You might be scratching your leg. You might be thinking about your homework assignments or what your going to do this weekend, but you’re not going to be doing all of those things in perfect synchrony with the presentation of each face each time and so when we only look at the activity that’s in perfect synchrony with the face, we eventually get an ERP wave form, which looks like this. So it’s a little bit smoother and yet it preserves the kind of features of each individual trial. When we think about ERPs there’s, this is the, the most basic way to analyze
them. There’s a now more sophisticated ways using multivariant statistics and I’m not going to talk about today, but we can think about ERP components
and an ERP component is really just the feature of an ERP wave form that we reason to be linked to some kind of
cognitive event. And the two aspects of an ERP component that we pay attention to are the amplitude, which is usually expressed in micro-volts, and that’s shown by that purple arrow there, and the latency, which is expressed in milliseconds, and that’s show by that, that green arrow there. So this would be a component and we would talk about its amplitude is how far down it’s going and its latency is when it peaks. When we talk about ERP components the way we refer to them is usually with a combination of one letter and a, a, a number or series of numbers and there are, for certain exceptions to this rule. But generally speaking we talk about things
being N or P, N meaning it’s a negative going electrical component, P meaning it’s a positive electrical going component. And then we can call it either an, like an N1 or an N2 reflects an ordinate value. So an N1 would be the first negative peak in a wave form. N2 would be the second negative peak in a wave form. We can also refer to it specifically with the timing of the peak and that would be, for example, we’ll talk about
today and N170. So N170 would a component that goes positive or negative? Come on, this is an easy one guys. That’s right, negative. And what will be the latency of N170? How does that, so N, so is a hundred seventy milliseconds fast or slow? That’s fast. A hundred seventy milliseconds is not a long time, right. So that’s one of the neat things about ERP. And that’s one of the reasons we’re going to talk about the N170 because it’s really, it, the first study that kind of talked about N170 was in 1996. One of my favorite studies of all time by a guy named Shlomo Bentin, who I believe actually did a post-doc here at Yale earlier in his career. And he found that when you show people lots of different
kinds of things you’ve got this negative spike at a hundred and seventy milliseconds that was largest and fastest to faces. It was a really robust finding. And what was so interesting about this to people, cause people, this had been looked at in other ways, but what was really interesting was to see that this happens so fast, that a hundred and seventy milliseconds after seeing a face your brain is treating that differently from everything else. So that was kind of news. So now since then there have been many,
many, many studies looking at the N170, all kinds of manipulations. What happens when you turn faces upside down? What happens when you do a, a photographic inversion of a face, so it looks like a photonegative? What does the N170 look like in little kids? What does it look like in people with autism? What does it look like in people with schizophrenia? So there’s been many, many studies of the N170. Some of the basic things to know about it are that it represents the, the earliest stages of face processing, maybe not not the earliest stage. There’s some evidence
that activity at a hundred milliseconds might also
individuate faces from other things or distinguish faces from other kinds of individual stimuli. We think that it represents structural encoding. So this is the stage of face perception in which your brain registers a face as a face, so not this is my mother or this is my best friend or this is my
neighbor, but just this is a face. The N170 is sensitive to inversion. Well, this is kind of neat. Remember when we talked about processing strategies and what happens when we turn a face upside down. Easier or harder to recognize? I’m going to keep you all awake. Harder to recognize. So we a, we might think, so if you were going to make a guess
about what would happen to a face-specific component, so we turn faces upside down, we stop treating them like faces, we turn faces upside down, what should happen to a face-specific ERP component? It should go away, right? We should, we would, we wouldn’t treat it as a face. Exact opposite. It actually gets bigger and it gets slower. And so that’s called the inversion effect. And so I mentioned that we can study ERPs in very young children. People have looked at face perceptions in very young children. So by three months we see specific activity elicited by faces. It happens later. So it’s kind of a, an amalgamation of activity distributed between an N290 and a P400. And then over time those seems to smear together. Both get faster. And we have the adult-like patterns by the
time a person is around fourteen years. So this is a, a face-specific component or, I should say, a face-sensitive
component, but we can also just look at other brain components and put faces into a paradigm in which other
things could be. So we could look at recognition memory for faces. We could look at the effect of salience for faces all I’ll talk about all those different kinds of things in some, in some of the ERP studies of autism that I’m going to talk about. So let’s move on and talk a little bit more about autism. What do we know about faces in autism? And I going to make a disclaimer right at the start, faces are now one of the most well studied, one of the most well studied areas of research in autism and I guess well studied, well studied gives an inappropriate connotation, cause well, well studied seems to suggest that, that they’re well understood and it’s the exact opposite. There’s been so much research in faces, but the research is really painted a confusing picture. And so I’m going to give you a story they can fit into one class today, but, but it’s a more nuanced story. And I’ll actually tell you about some of the work that we’re doing to shed light on those nuances at the very end of my lecture cause that’s one of our, our, our lab’s goals now is to try and understand well, why does some studies find certain problems with faces and other studies don’t? Why, why do we see this heterogeneity in face perception in autism? And it’s worth mentioning, it’s worth mentioning one of Dr. Clinton’s first slides showed the idea of an autism spectrum, right, so there were lots of people, all different
colors, under a rainbow. It looked like some kind of happy autism party. Was it, if we think about the that we diagnose autism, right, there’s a list of twelve symptoms. How many symptoms do you need to get a diagnosis
of autism, not even autism spectrum disorder, autism, the most severe diagnosis on the spectrum? Does anybody know? Six. Six. So, six of twelve. So you could theoretically have two children diagnosed with autism
with non-overlapping symptoms. So it makes abs, to mean, absolutely perfect sense that we would have heterogeneity in research studies of people with autism. So one of the really most robust findings in autism both clinically, and I’m, I’m sure many of you have noticed this now in your practicum places is that people with autism seem to approach faces in a different way. Before we had these really elegant studies that we have now, where we’re taking infants who are at risk for autism by virtue of having an older sibling with autism, and studying the development of the disorder in a prospective way, we use to study it in retrospective ways. So one way to study things retrospectively is using video tapes. And so my graduate advisor, Geraldine Dawson, and a person who was a graduate
student at the time, Julie Osterling, had this idea to look at first birthday parties. So it’s a nice experiment, right, but what do we want in an experiment? We want things to be well controlled, standardized as the same for everybody, and we can’t really do that with home videos, but for birthday parties the same kinds
of things happen at every birthday party, so we have a nice comparison to see how infants might be different. And also when we’re interested in things like social referencing, social referencing is the idea that you look to a, another person’s face to figure out what to make sense of some, what, how to make sense of something novel, and so what better situation to elicit social referencing in a one-year-old
child than for the first time in their life to take
out a, a piece of dessert, put it in front of them, and then set it on fire, right. Most kids have never had parents set their, their highchair on fire before. And so it’s a nice chance for students, for, for kids to try to figure out is this something good, is this something bad. And so what they did is that they looked at these
home videos and they found that first birthdays, and then in subsequent studies, even earlier, by six months, kids who would go on to be diagnosed with autism look different from kids who went on to develop typically and also kids who went on to have non-autistic developmental delays. We know that throughout the lifespan, people with autism have more trouble with recognizing faces, with interpreting emotional expressions, with maintaining eye gaze. That it’s really striking, I have encountered striking anecdotal examples. A fellow I worked with at the University of Washington was a, a man with high functioning autism and he’s interest, his preoccupation was food choices. And so in the halls of the building he would approach me and say Jamie, do you, do you like apple pie or do you like pumpkin pie? And then I would say I like, I like both and he said well, do you like them or do you love them. And he would kind of ask this series of questions to really get at your, your food preferences, but when I would see him outside of work I’d walk past him on the street he wouldn’t recognize me, he wouldn’t say anything, but then if I’d say hey how’re you doing, he would say do you like apples or do you love them? And so he, he needed a context for my voice to recognize me. We also see different processing strategies for faces in autism. We see a reduced inversion effect, so they don’t have the same decrement in performances when we turn faces upside down. We don’t see the same decomposition effect,
in fact, some studies have shown that they’re better at featured-based matching, especially if it revolves around the mouth. And so we infer that people with autism aren’t using this configural processing strategy that we’ve talked about. They’re approaching faces in a piecemeal way, the way most of us approach objects. You’ve heard someone speak much more eloquently than I would be able to about this already, but Dr. Clinton and Warren Jones and others have looked at the way people with autism look at faces and look at social information. And we know that people with autism look less at the eyes. They look more at mouths and things. When there’s three people interacting on screen, they have a harder time tracking those interactions. And they, they fail to follow attentional cues, things like a person pointing their finger on screen. From FMRI research, that actually happened here. Bob Schultz, another close colleague who has since moved on to the children’s hospital of Philadelphia to start the center for autism research there to produce another seminal paper at the child’s study center looking at this activity in the Fusiform face area. So we’ve talked about how Marvin Chun and Nancy Kin, Kanwisher found this hot spot in the brain for faces, well Bob looked at people with autism and saw how their brains activated to faces and he saw that this activity was, was reduced in people with autism, despite activity to objects looking very similar. So now let’s talk a little bit about ERP studies of face-related brain function in autism. so we’re going to talk about three different areas, so face recognition, emotion recognition, and structural encoding. And so first I’m going to talk about face recognition and this is work we that we did at the University of Washington as part of a study of early development of
children with autism. We did this work in three-year-olds and this was actually based very closely on a paradigm used in typical development, a paradigm created by Chuck Nelson. And so what we did is we showed children familiar and unfamiliar faces and this is the slide where someday when my daughters are old enough to log on to Youtube, they can still think that I’m a jerk, but at least they’ll know I wasn’t a hypocrite. So we, we showed them familiar and unfamiliar faces and familiar and unfamiliar toys. And we contrasted brain activity. So what’s the difference between a face and a toy in terms of, think about the developmental paths I talked about earlier, which path is for faces? The social path or the non-social path? Which path is for toys? The less social path, right. And so we have a nice kind of, a nice design where we can look at familiarity for social information and familiar, familiarity for non-social information. And we had a, a reason to, to have certain predictions based on typical development. We thought that in typical development we would see different, differential activity to familiar versus unfamiliar faces and objects because that’s what we’d seen before. When we looked at people with autism we saw something very different, so these are very young kids. These are three-year-olds. So I was there when we collected the data. It’s, I I cast a rosy picture about the applicability of ERP for studying a range of developmental
functional levels and a range of ages in autism, but it’s still really an adventure to try to do an ERP experiment with a three-year-old
person with autism who doesn’t have any language. It involves lots of energy, lots of toys, and lots of m&ms. And so what we saw is if we look at objects and these are both wave forms for people with, for the young children with autism, we saw this component, the P400, it’s called, and it’s associated with recognition. So we saw an enhancement to novel objects, and, relative to familiar objects. Now these are faces. So we the same, we see the same kind of peak, but what’s different between the faces and the objects? Right. And so we saw that when we look at the non-social information, they look just like their typical counterparts. For the faces they didn’t. They weren’t showing differential brain activity. And so, when this study came out one of the concerns was that we were saying that kids with autism don’t
recognize their mother, which isn’t the case at all. I was there. I was running these kids. They, they knew their mothers and they often ran to
them frantically when we tried to do the ERPs with them. They certainly recognize their mothers, but it’s telling us they’re using different mechanisms to do that. And that’s one of the things I think it’s really important
for us to learn about autism. What are the compensatory mechanisms? So in another aspect of social information processing that we’ve used ERP to study in very young children with autism, and these are the same group of three-year-olds, is emotion recognition. And so for this study we contrasted their brain responses to neutral versus fearful faces. And fear is a really useful emotion to use because fear is closely linked to
the function of the amygdala, which is, which is one of the social brain regions involved in autism. And how do you get a, what a, a eight-month-old child to show fear. You show her her older sister coming at her with one more sticker that she’s about to put on her face. So we show these three-year-olds neutral and fearful faces and to be clear, we did not show them neutral and fearful faces of my daughters. These were from a standardized series of faces, developed the Ackman’s series, they’re called, but we can’t show them for the purposes of this lecture. And again, so this is a different ERP component. This is, against, it’s not a face-specific component, it’s just kind of associated with salience. It’s called the negative slow waves. And in the typical kids we saw a big difference between the fearful face
and the neutral face. But what did we see in the kids with autism? Difference or no difference? No difference. And so one of the nice things about this study is
that ERPs are kind of abstract. Right, we do them in a, the lab. We can make guesses about how looking at pictures of emotionally faces versus neutral faces maps onto things that happen in real life, but it’s kind of a stretch. So what we did in this study is we also did this kind of response-to-distress task, where graduate students like myself played with the kids. We sat at a table. It was videotaped. And we had this hammering toy and so we would play with this hammering toy and we would pretend to hit our finger with the hammer and then we would pretend to cry and we would just cry from like a minute. And the video, and afterwards we’d look at the videotapes and determine what the kid did. Did the kid just think “Oh great, you know, this guy stopped playing with the hammer. Now it’s my turn”? Or would the kid look said? Would the kid pay attention to me at all? And this is one of the times I regret that we can’t show the picture because we have this, a great picture from that study, where I’m sitting there crying and a little three-year-old boy with autism is hammering
away, but his mother is looking at me, but it’s not a pathetic look. It’s a looking like what is wrong with you. So, and what we found was actually, so, if we, if we wanted to make a jump about how sensitivity, neuro-sensitivity to expressions, to emotional expressions, would map on to behavior, we might think of these things being connected. And that’s exactly what we saw. So a different component, the N300, it’s latency, how long it took happen was associated with the amount of time these children spent attending to feigned distress. So looking now at some different work. This was, again, work done at the University of Washington and this is work done in adolescents and adults with autism. We took that study done by Shlomo Bentin, the classic 1996 one, and looked at the N170 and people with autism. We should them upright and inverted faces . So I describe the N170, but I hadn’t shown you one. So this is an example of an N170. This is from fourteen typical, typical adolescents and adults. And what we see is that negative dip in electrical activity that happens around a hundred seventeen milliseconds, and this is associated with faces. And when we showed these same faces to the people with autism, we saw a different kind of response. The, it did, it wasn’t like it didn’t have an N170, but it was different from the typical counterparts. And I
should make clear that these people were just as smart as typical counterparts. They perform similarly on many non-social
behavioral measures. But they had a very different response and they’re response was actually something that we could only pick up with ERP. There’s a, they’re response was to be slower. So while most people have N170s around n, around 170, 180 milliseconds, the people with autism were much slower. Then we also looked at the inversion effect. So if we show them the faces upside down would we see a different response? And so this is the, what an inversion effect looks like in typical people. So you see a big, the red light is upside down faces, the blue line is the upright faces. And so what you see is a bigger, slower response to upside down faces and, in the kids with autism, the adolescents and adults with autism rather, we say some slightly different response. So we did see maybe a little difference in amplitude, but what was really salient was, again, the timing. So, whereas typical people slowed down when they saw an upside down face, people with autism there wasn’t any difference. The,
in terms of the timing, they’re upright were equivalent to their inverted faces. And that’s shown by the, the slope of these purple lines there, those, those purple lines are the inversion effect. So what we saw in these adolescents and adults were slower processing speed and insensitivity to inversion and, excuse me. Again we wanted to see if we could tie this to something, to some kind of behavioral measure that we could be sure was more ecologically
valid, or we could be optimistic was, was ecologically valid. And what we, so we administered a standardized test of face recognition. It’s part of a memory scale called the Wexler Memory Scale and we looked at how good people were at recognizing faces. And so again, despite being comparably intelligent,
people with autism made twice as many mistakes on a face-recognition task. And, moreover, these mistakes correlated with their processing speed. So how face a person showed this spike to a face was actually associated with how good they were at face recognition. So this was actually the first study to look at the N170 in autism, but since then there have been many studies
and what has emerged is that we see that across a number of studies there’s delayed latency
for faces. This has been found in children as young as three years of age. What’s very interesting is that the same effect has been found in parents of children with autism and in a very recent study by my colleague Joe McClearly in the, in the UK. He spent of it in ten-month-olds, who are at risk for autism, but haven’t been diagnosed. We’ve replicated in other studies the intensity to inversion and there have been other forms of atypicality. Some studies have found decreased amplitude. Some have found abnormal lateralization or patterns of activity at the scalp that are more characteristic
of younger children. And again as I said before, not all of these results are replicated across
all studies. It’s really a heterogeneous picture. And I’ll talk about some manipulations that we’re doing now, some experimental manipulations to understand more about why we see some effects in some kids and different effects in other kids. It seems like part of the picture you’re, you’re suggesting that kids process faces like objects. But it seems like in one of the presentations you were showing they don’t process faces like objects. They, they recognize objects better than they recognize faces. So, aren’t those two things kind of contradictory? Well, let me, let me go on to the next part as see if, I don’t think that faces are processed like objects. I think that faces may not be processed in a special way by people with autism. But it’s actually turns out that objects can also be processed in a very special way, which I’ll talk about right now. So what do we make of this? Do we think
that people with autism are just born with a hole in their brain in their face-processing regions? Do we think that they’re unable to do this kind of information processing in their brain? No. We kind of explain in a developmental way. So we know that faces are processed in special ways. We know that the, the specialization associated with face processing happens over time. So what if people with autism come into the world less drawn to other people and therefore they fail to, to pay attention
to people and they fail to become face experts. So if we think about our path towards social expertise culminating in face expertise, we could think about people with autism failing to
chart that course. And so we published this and we called it the social
motivation hypothesis. And the idea is that the problem in autism is really decreased social motivation, which leads to inattention to faces, which leads to a failure develop expertise and then that’s reflected in the, the atypical specialization we see both in terms of brain and behavior. But there’s an important presumption here, and this is something
that been very interesting to me that I’ve studied over the past couple of years here at Yale is, is this piece. I started off today talking about how we have different explanations for autism and it, it might be a social problem, but social information could all just be a red herring. Maybe it’s a problem with complex information processing. And we know that the development of expertise is something that requires complex information processing. So what if people with autism just have a problem developing perceptual expertise? So how can we look at that and what is perceptual expertise? So when we talk about perceptual expertise it’s the idea that as we become really good we get a lot of experience distinguishing among things that are very
similar like faces or, if you are a monkey expert, like monkeys we start to treat them different. So we start to treat the faces, we start to treat those objects or those non-face things the way we treat faces. We starts to see signs of holistic processing. We start to see inversion effects. We start to see activity in the fusiform gyrus, and most relevant to us, we start to see enhanced N170 amplitude. One thing that hasn’t been studied yet what, well, isn’t, isn’t will understand it yet is to what piece your affective experience plays in. So I have there a, an example of a car and a bird and those are both things that have been studied in neuroscience research to show expertise effects. When a person gets really good at individuating among birds or different kinds of cars, they get a bigger N170 than people who don’t care about them. But what hasn’t, but what we don’t know is, it’s rare that a person develops some kind of
expertise without some kind of personal interest. So car experts aren’t just car experts in the way. You know, like if you think about a baggage handler, they see lots of bags, but they probably feel differently about bags than car experts feel about cars, right. And so that’s something that isn’t studied. And I think it’s relevant to studying perceptual expertise and autism cause the two ways that people have gone about it so far are to either train people with autism to be expert in
something or to look at something they’re expert in already. So the training studies teach a person to become experts in a particular area. What’s nice about this is it makes for a very
clean elegant experience, experiment because you have a group of people then who have all comparable degrees of expertise. You’ve controlled their access to it, you know. But what the problem’s with it is it seems not really the way we develop expertise in real life. So there’s not intrinsic interest and there’s not much affective involvement we would assume. Now naturalistic studies seem to solve those problems. People become experts in things because they’re interested in them. And many people with autism really become experts in things. The problem is, is that it’s hard to find groups of children who are all expert in the same thing, so that we can do a clean experiment. So, this is a problem that we had kind of thought about quite a bit. One of the nice things about being a clinician is it sometimes you don’t have to have good
ideas, good ideas kind of walk into your clique. And so one day I was working with a kid, a four-year-old boy, who was very bright. We had followed him since he was two. I’m talking about this, this is my favorite video to show, but, again, we can’t show it, so we’ll do a little re-enactment. But we were doing a play session and he would, he would say things different, he, he would see things very differently than I would. So, you are unfortunate to be sitting right up front. So you’ll, you can be, you’re going to be the boy. So what’s
in this bag? W. I, I was a, I was afraid that was going to happen. The, these are phone blocks. We’ll try a different one. No, you, I got it wrong. Okay. What, what do you see there? A boy snorkeling. Can you tell me anything else about it? No. Okay. So these are, these are pieces of actually a diagnostic assessment that we use called the ADOS. Whenever I would bring out the boy would see as a letter. So, the boy and one of my students saw these as Ws. To me they were just blocks. When I brought this out I said “Oh look! There’s a guy snorkeling.” And he said “Yeah, the snorkel is a J.” When I brought this out I didn’t even realize this was happening. I brought past fast his face really quickly and he said “WPS.” I said “WPS?” And then I looked oh Western Psychological Services, the company
that makes it. So this boy was seeing letters everywhere. And it actually turns out it’s a pretty common
area of expertise in autism. So many young children with autism get the very interested in letters. We’re not exactly sure why. We think that because
letters are omnipresent and they’re nice because their always the
same twenty-six and they’re always in the sequence, so they, they kind of fit, fit the rules for a person who likes ritual and routine. We find that’s an area of strength for people on the spectrum. Even though problems with language is a, a, are a really salient part of autism, we see intact word reading and decoding in most children with autism or at least what would be predicted by their intellectual level. And then there’s a subgroup of children, who have what we call hyper-lexia, who are really precocious, self-taught readers. And that’s a five to fifteen percent prevalence. A lot of the really good work in hyper-lexia
has been done right here by Elena Grigorenko and Tina Newman out of Naples. So we’ve got an area in which many people with autism develop an expertise, but it’s only good to us as people who are interested in
the brain, if it gives us a way to measure precept, perceptual expertise in terms of brain function. And it turns out it does. So a colleague Alan Wong, who at the time was a graduate student with Isabel Gauthier at Vanderbilt and is now at the University of Hong Kong looked at how people learn to process letters and he did a very nice experiment, where he took letters in the Roman alphabet, which is what we read, you know, what you’re seeing here. Then he took Chinese letters and then he made up an alphabet and he showed these letters to people and measured their brain response. And what he found was that you got an enhanced N170 if you could read the letters of an alphabet. It didn’t matter which alphabet. So if you were bilingual reading Chinese in
English you get a bigger N170 to both Chinese characters and Roman characters. If you were a person who could only read English, then you’d get bigger N170 to Roman characters, but not to Chinese or pseudo-font. They were equivalent. So what this let’s us do then is kind of map out those endpoints. So if we think about our social expertise path ending in faces we could take a look experimentally at a non-social expertise path ending in letters. And so we contrast things that we think we’re social experts in versus not experts in with houses and then pseudo-letters. And this is some of the recent work that we’ve
done in people with autism. And so what we’ve compared is expert and then non-expert stimuli in the social domain, faces versus houses, and in the non-social domain, letters versus social letters versus pseudo letters. And then what we do is we take the N170 record it from this a two-hundred-and-fifty-six electro-net and we record the N170 from patches on the right and left hemisphere. And so for faces we saw the kinds of things that we’ve seen
before. This was a younger group of children than I’ve studied before, but we found in our test of face recognition they performed significantly worse than their typical counterparts, despite being as, as
generally intelligent as them. And we saw in the right hemisphere, the hemisphere that’s
most often associated with face perception, we saw that they had, a, a slower latency just to faces than typical individuals. When we look at houses, both groups were equivalent. I talked earlier about source localization and we’re starting to dabble in it, although we’re
not necessarily zealots. But for both groups we saw that the N170 localized to the fusiform gyrus. So it’s not like there’s really qualitatively different kinds of things happening
in the brains. It’s just happening in a different pace. But what was really intricate, interesting to us was letters. So first we looked at, at behavior. We looked at reading in two different ways. So we can look at reading words. Reading words can happen in, in, in, with different kinds of strategies. We might recognize them based on the shape of the word or we might sound, sound them out. But we can force a person to sound them out testing their mastery of all the, the individual pieces of the word if we make up words. So if we use words that nobody has ever seen before. The only way you can pronounce it correctly is you understand the rules of, of sounding out words. And on, on both kinds of measures people with autism scored just like their typical
counterparts. And both groups scored in the average range. So we know because this is a norm test that it’s not something idiosyncratic about people who live in New Haven. They’re performing just as well as anybody in their age range would. When we look at the N170, the first question really was would we see an enhanced N170 to letters even in the typical adolescents and children adolescents because it hadn’t been really looked at in a group this young before. And that is what we saw. So the pink highlights the N170. And you see the purple line is the letters. The green
line is the pseudo-letters. And we see a larger amplitude to letters. And what we see in the group of autism we did. We actually saw a, a bigger difference between
letters and pseudo-letters in the group with autism. So when we, when we compared the groups, both groups showed an enhanced amplitude to letters. There was no differences between the groups. The typical group showed that the expected pattern of left-lateralized response. But the group with autism showed bilateral specialization. You can really see it here. So this is a, a picture, kind of a, think of it as a heat map and the darker the purple color shows the more negative the activity. And so what we’ve found is the typical group will see things localized to the left. The autism group actually recruited right hemisphere regions, which is kind of interesting because those are the regions typically involved in face perception. So we see in this experiment, we see that they have impaired face recognition. Atypical neuro-responses to faces they show intact word reading and preserved, kind of enhanced neuro-response to letters with the recruitment of the right hemisphere. So what does this tell us about autism? Well it makes the case that their brains, their brains can learn. None of us are born learning to read, I’m pretty sure. We have Yale students, if anybody could, you guys could. And I’m pretty sure you couldn’t. So we know that these are things they’ve learned over the course of development. We know that to learn these things is kind of a complicated brain operation. It requires your prefrontal cortex to be compute, communicated with cortical regions way in the back. So we know that, that things like this can work in the brain. It tells us we need a more nuanced story. So we need to look at connectivity within specific systems rather than just generic dysfunction. And this also gives us encouragement that the all these different kinds of interventions
that we do aiming to improve social information processing by driving people with autism to attend to these
things may payoff. So now I want to talk about, this is a, this is all the more cutting-edge stuff. So this is stuff that, that isn’t published, hasn’t been talked about before. These are some of the things that we’re working
on now. So I’ve alluded to this earlier, but one of the, I, one of the things we’re very interested in understanding now is why, what accounts for the heterogeneity in autism, especially in terms of faces? So why do we see some kids showing delayed responding and other kids not showing delayed responses across studies? And there’s different kinds of ideas that have been
put forward to explain it. One involves visual attention and this is pretty
straightforward. If people with autism are always looking at
different parts of the face than typically developing people, we’re going to expect different patterns of brain activity. So we could look at how visual attention maps onto face perception. Another piece is social motivation. And this was a, a, a neat interaction for me. This was a group of parents, actually were here at the Child Study Center, and I gave a talk on so much of this. I showed our model social motivation hypothesis and a guy came up to me afterwards and he said “Jamie, what you just said doesn’t make any sense. My son has autism, but he is super socially motivated. He has spent his whole life getting in people’s
faces trying to interact with them and he’s a really odd, awkward, and often unsuccessful approach, but he’s very motivated.” And it’s a very good point, right. In 1979, Lorna Wing talked about different groups of children who, who were active, but odd versus passive versus aloof. And we really don’t have a sense of how those kinds of differences within the very diverse group of people
that we would call people with autism maps onto difference in brain activity. And then finally the third potential explanation is looking at connectivity within these face perception systems or dysfunction within individual components cause We’ve really talk today about face processing as a thing, but it’s not. It’s really the, a, the collection of a lot of individual things
that happen in the brain. So I’m going to now show you some preliminary data that we’ve, that we’re using to start to look at these things. So in terms of visual attention, what we’ve done, and this is with a, a graduate student who was hear last year, who’s now getting her PHD at the Institute of Psychology in the UK, Celeste Chung, and we’ve, well, if you want to know how looking at different parts of a face
could affect the neuro-response, what kind of experiment could you do? Right, what could you do? Sure. You could do that. And that’s actually been done. The very first N170 paper showed different chunks of faces, different pieces, but the problem is you’re, you’re changing the face. You’re just showing the eyes. But one thing you can do is force them to look at different parts of the faces, right. So you can have a cross-hair on the screen that makes them look at the eyes or makes them look at the nose or makes them look at the mouth. And this is what we’ve actually been doing and this is in typical adults. And the idea is that maybe people with autism are showing different brain activity
because they tend to look at the mouths rather than the eyes. And indeed we expected that when we force people
to look at the eyes, we’d get stronger brain activity, a stronger N170 than if we forced them to look at anywhere else, but that’s actually not what we’re finding. We’re finding that whether you look at the eyes or whether you look at the mouth
you get a bigger N170 than if you look at the center of the face or if there’s no cross-hair at all. So, it’s almost like looking at information, which parts of the
face elicit a bigger N170 than just eyes. In isolation the eyes actually elicit a bigger N170. So we’re now starting to do this paradigm with people with autism. The question will be when we compare people with autism and typically developing peers, controlling for where they’re looking, are we still going to find these same kinds of brain differences or, or is it really explained away by, by where they look. And hopefully next week Kevin Pelphrey will talk to you about some of the really neat FMRI work that he’s done showing that when you control, when you manipulate a person’s scan path in the magnet, you can make typical people look like they have the brain activity of a person with autism and vice versa. So the other piece is social motivation. So we’re, we haven’t yet started to tease apart groups of people with autism with social, who are motivated for social interaction, who are, who are more aloof, but we’re actually looking at it in the typical population because if you think about it, we all vary, right. There are people in this room who are going to spend Friday night in, you know, in some party, talking to lots of people and there’s going to be people in this room who are going to spend Friday night in the library. I’m assuming you all are going to be Friday night in the library, reading about autism, but I know that’s not true. Right, and so you might say that the people who are at the party are extroverts and the people who are at the library are introverts. And so actually, what we’ve done is we’ve brought, we’ve screened people to be really extreme introverts or extreme extroverts and we’ve brought them in for ERPs. And we’ve really been surprised by what we’ve found, really striking differences in brain activity. And these are all people, these aren’t people with autism. These are people out and about. But if you look in blue are extroverts and if you look at red are introverts. And again, this is work done by Celeste Chung. You see that the extroverts have bigger N170s and really what’s also salient is extroverts show an inversion effects and introverts don’t. So this is very much in line with the idea that social motivation shapes our brain activity. We can think about it in developmental way or we could also think about it in terms of a salience way. Maybe social information is just more salient in the moment for extroverts. And then now is a, is a, this is a big slide, so I’ll, I’ll get you ready for it. The idea that face perception, I’ve talked about the N170, but the N170 represents one stage in a series of stages of face, of, of the face processing system. And so what we can do because of the temporal acuity of ERP, we can tease it apart. So this is kind of a mock-up of a theoretical, a, a, a possible explanation of the way face processing works in the brain. So if we think about a component called the P100, showing us basic visual processing, the N170 showing us structural encoding and things like the N250 showing us higher-order face processing like affect recognition or identity recognition, we can think about how those things tie in to the mirror neuron system and then we think about how those things tie into related behaviors like imitation or face perception and then how those things influence vie, how it influences social interaction. And we have ways of measuring social interaction in real life. And so we’ve actually just submitted this as a grant actually today. A grant went in to do a study with College of the University of Washington to look at just this, to use ERP to break face processing into individual components and then to see, well, if we are finding that some people aren’t, some people have delays in the N170 and other people don’t, maybe if we look at the broader array of, of neuro-functions associated with face perception and beyond, we’re going to start to see different profiles. So maybe there’s slow N170ers who compensate with fast N250s and actually look okay here. Or maybe they’re slow N170 people who have even slower N250s and have really big problems here. But with, with statistical approaches like structural equation modeling we can actually test the directionality of these arrows and look at in an empirical way which models best fit different groups of people. So we can
compare for sure people with autism and typical people, but even more interestingly, we can then try to tease apart different groups of people within the category
of autism. And this, I should say, this is developed with my colleague Ralph Bernier at the University of Washington. And then the next step is, this is work that we’re not doing yet, but it is
imminent, we’re going to take advantage of the applicability of ERP to babies and we are going to start doing ERPs on little babies who are at risk for autism to try to track the development of social behavior in a prospective way. And what we’re also going to try to do, we’re already doing in adults, is try to get around that problem of what people are looking at by recording ERP and I-tracking at the same time. So with Dr. Clinton and Warren Jones, we’re working on systems so that, they have as, as you’ve seen really elegant ways of I-tracking in infants and we can record their brain activity and what they’re looking at at the same time. And the idea is to kind of really do a broad, a broad, broad measures across domains of perceptions, so looking at visual information by comparing faces and toys, looking at auditory information by comparing voices, and then as me and Warren are, are inclined to do, using more nationalistic
stimuli, so of examples of mothers and other people talking and objects moving to music and examining in real time the brain response to that. So I want quickly acknowledge all the people who have helped with this research, most importantly the children with autism and their families who come in and tolerate all the things that we ask them to do in the hope that we’re going to help future generations of children with autism. Many colleagues here at Yale, colleagues in other places, and to Nora and Agnus, who, although they didn’t have a say in the matter, will have retrospectively permitted me to, to plaster their face all over the internet. Thank you.

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