Become a Creator today!Start creating today - Share your story with the world!
Start for free
00:00:00
00:00:01
ADHD science episode 1: Natalia Zdorovtsova
490 Plays1 year ago
The brilliant Natalia joins us for a chat about her research, looking at the links between brains, thoughts and behaviours in ADHD and other conditions.
Natalia can be contacted through the Cambridge Neuroscience website: https://www.neuroscience.cam.ac.uk/directory/profile.php?nz01
Recommended
Transcript
Max and Tess Return with a New Podcast Format
00:00:08
Speaker
Hello. Hello. So let's introduce ourselves again. I'm Max Davey. And I'm Tess Davey. And we're back. Yep. We spent a year since we've done a podcast. Oh my god. This is going out. This is kind of a new podcast for us. Although it's going out on the same feed as the old podcast. OK. So some of you will be listening to us because you previously listened to
00:00:34
Speaker
extraordinary brains which was up and if you just joined the podcast and you're listening for the first time it's on the feed 25 episodes of neurodiverse people's lives that we explore and talk about how they've got to where they are now so some really good interviews there but this podcast is
ADHD Researcher Line-Up and Episode Structure
00:00:57
Speaker
Science. It's the ADHD Science podcast. We're doing it in partnership with the charity ADHD UK, which has the advantage that they're going to do the publicity. And if you want to talk to us, ask us questions, then ADHD UK is the way to do it. So their Twitter, their Instagram,
00:01:23
Speaker
their other things are dog who obviously makes cameos every so often being annoying and they have a little section on the website where you can submit questions and comments as well we really really want you to do that because we've got some brilliant
00:01:39
Speaker
Seven brilliant researchers for this season. We're going to put one out a week. We've all recorded them all and they're all ready to go. We just need to put them out. And so we want to know what you think of them and what you want to know more following the conversations that we're going to have.
00:01:59
Speaker
yes yes yes i don't really have anything to add i'm just agreeing with you yes good well that's just first time for everything um all right so we will um get straight on without further ado with the um first interview
Interview: Natalia Zadora-Fudzova on Cognition and Behavior
00:02:17
Speaker
Natalia whose surname I can't pronounce and I will demonstrate my lack of pronunciation in the interview and I try and pronounce it and she's from the University of Cambridge and she's gonna talk us through her research into statistical analysis of different sorts of cognition and behavior but more importantly I think she's going to
00:02:44
Speaker
explain what some of those things mean and give us a real foundation for the rest of the interviews. Oh exciting! So it's basically seven interviews coming up ADHD researchers starting with Natalia. Follow our Instagram. Follow the ADHD UK Instagram. That's what I meant. Yeah okay all right let's go!
00:03:11
Speaker
Right. Hello. Hello. Hello. Welcome everyone. Um, we are joined today by Natalia. I'm going to run up at your surname. Zadora Fudsova. Yeah. Hi. It's very nice to be here today. Natalia, please tell us where you research and what you're talking about today. Cause it's a fascinating subject to kick off our series.
00:03:38
Speaker
Yeah, so it's wonderful to be here and also to kick off the series with you. I'm a researcher at the Cognition and Brain Sciences Unit at the University of Cambridge. I'm in the third year of my PhD, so I've been working on this for a few years now, doing my independent research within my lab and also some collaborations with other researchers. And what I'm looking at primarily is the relationship between
00:04:06
Speaker
brain structure, brain function, which I'll explain later if you want to go into more depth about that, cognition and behavior. And specifically, what I'm interested in is inattention and hyperactivity, and how that relates to different properties of brain networks, as well as cognitive differences that might potentially determine learning outcomes in children and adolescents.
00:04:30
Speaker
Great. So that's a really great encapsulation of what it is that you're doing. But I thought we thought we could go back really to basics and what do you mean by structure? What do you mean by function? Let's start with that, shall we? Yeah, sure. So when you're looking at data at multiple levels, you have to be more precise with your definitions in order to be really clear about exactly what it is that you're looking at.
00:04:56
Speaker
So to kind of start off from the basics of the brain data that we're using, for brain structure, what I mean is MRI scans. And we have a sample of 1,000 children from the kind of east of England, Cambridger area, many of whom are struggling learners. So they've been referred to us at the Center for Attention Learning and Memory, or CALM, for a wide range of things.
00:05:24
Speaker
Not necessarily a diagnosis that they have, but let's say they're struggling in their maths course or they're struggling behaviorally at school. And they've been referred to us and they've gone in for an MRI scan that looks at brain structure. Another one that looks at brain activity when they're at rest. So when they're not doing anything in particular. And then also three to four hours of cognitive and behavioral testing. So we have a ton of data on these 1000 or so kids. And for brain structure, what I mean is
00:05:54
Speaker
just an MRI scan looking at white matter tracts in the brain. So all the different fibrous connections that keep the brain together and allow information in the form of electrical impulses to travel between different regions of the brain, allowing you to think, coordinate your behavior and that sort of thing.
00:06:12
Speaker
Just to break it down really basically, if you think about, if you slice through a brain, it's a little bit, I know this is gonna offend you as a neuroscientist, Natalia, but if you slice through a brain, it's a bit like slicing through a cauliflower. And the white matter and the gray matter is the bits on the outside and the gray matter is like the stems. Yeah, the gray matter is like the florets.
00:06:36
Speaker
The white matter, you're right, they look really similar and that's because a lot of things in nature look that way. The white matter, if you're thinking of a cauliflower, would be the stem and the branches of the cauliflower leaping off of the stem.
00:06:53
Speaker
So it's all of the parts of the cauliflower or the brain that are connecting it together and allowing nutrients in the case of the cauliflower or electrical activity in the case of the brain to be passed through the whole network.
00:07:10
Speaker
I mean, I should definitely know this, but is the MRI... I thought it was going to be a codifier question. Okay. Is the MRI the one where they take lots and lots of different photos of different sections of your brain? Like slices through, yeah. Slices through and then they layer them to create a sort 3D image. Is that the one? Yeah, that's exactly it. So you go into the MRI scanner, it takes lots and lots of slices of scans.
00:07:34
Speaker
over the course of about half an hour in our case because we're getting a structural scan and also a scan of brain activity at rest.
Understanding MRI Scans and Brain Data
00:07:42
Speaker
And then what we do to the structural scan is we take that image for each person and we don't just eyeball it, but we look at the density of these white matter connections and then we turn them into numbers. So we kind of convert
00:07:55
Speaker
this image that you can look at of a brain and we convert it into a format that you can actually use within a data analysis pipeline. And this format is typically a matrix or a connectome. I might refer to connectomes during our discussion and what that is, it's basically a matrix that represents
00:08:16
Speaker
how strong connections are across different regions of the brain. And it's a nice way of mathematically formalizing what's otherwise a really, really complicated network that differs so much between people just visually, allowing you to compare the density of white matter connections between people and also summarizing your data in a way that makes sense and preserves the valuable, I guess, components of brain structure while, you know,
00:08:45
Speaker
getting rid of things that might unnecessarily complicate your data analysis. So that's what a connectome is. That's what we do to our MRI scans, both structural and functional. And it allows us to essentially look at how brain networks map across the brain and how they connect to one another. And you've referred to functional MRI scans. So what's the difference there? What makes them unique and how do they look at different things?
00:09:13
Speaker
Yeah, so structural scan, it's just sort of a picture of your brain. It's gray matter and white matter. And you can look at either and that's very interesting in itself. But for brain function, a functional MRI looks at blood hemoglobin concentrations in the brain across time. So we're not actually looking at the electrical activity itself that's going on in the brain.
00:09:39
Speaker
But we're looking at a proxy for it. So we're looking at how blood oxygen travels around the brain, supplying different areas of the brain with oxygen and nutrients, and kind of inferring that that relates to the brain activity. So that's what a functional MRI is picking up. And so we do about a 10-minute functional scan when a person is
00:10:01
Speaker
completely at rest, so we have their eyes closed. They're not thinking about anything in particular. And what you notice is that across those 10 minutes or so, you get a distinct firing of certain networks that occur by themselves. They're correlated within themselves. And these are called intrinsic connectivity networks. So these brain networks are things like the default mode network, the visual network, the executive network here at the front of the brain,
00:10:29
Speaker
And each one can kind of be looked at independently or compared in their connectivity to other networks to find out interesting differences between individuals. And that's what we kind of get out of the resting state scan. Yeah, okay. Does that make sense? Enough. I think you explained more as well. I mean, it isn't easy stuff. And so then you talked about behavior and cognition. So I think those are probably two things to
00:10:59
Speaker
It's definition now, but I think it's important to have these foundations so we can kind of go on from there. Yeah, right. It's really good to have clear, precise definitions when we're looking at these things because I know especially within colloquial language, we tend to refer to maybe behavior or thinking or cognition and get a lot of terms intertwined in a way that makes it hard to do neuroscience research in a way because you have to describe things more formally
00:11:28
Speaker
and therefore maybe change the way that people use language from the outset. So what do we mean by cognition? In this case, we mean people's test scores on a variety of cognitive tests. So let's assume that the brain is an information processing unit, which a lot of scientists like to think that it is because it seems to be taking information from the outside world.
00:11:56
Speaker
doing something to it through its electrical activity, and then allowing you to act in certain ways in the world that, you know, basically let you adapt to your environment. And there are multiple different cognitive capacities that relate to different types of information processing. So, for instance, there's memory. You're processing information about things that happened in the past.
00:12:26
Speaker
visual spatial reasoning. So you're processing information about things that are occurring in space that you've received through your visual sense. There's language processing, where your brain is processing something about language that you've read or heard through your visual sense or your auditory sense, and multiple different other kinds of cognition that
00:12:50
Speaker
relate back to this information processing idea that I discussed earlier. And there are different tests that you can give people to assess each type of cognitive modality or type of cognition. And people tend to vary a lot in their cognitive ability, both very generally, so in terms of general intelligence, but then also within different cognitive domains, like language process, visual spatial processing, memory,
00:13:20
Speaker
And these are the individual differences that we're really interested in. Okay. Does that make sense? Sure. I mean, it's sort of, it's sort of, it's sort of the water in which I swim all the time. So it's difficult for me to kind of say.
00:13:35
Speaker
So executive function is one of the main ones. If we're discussing ADHD, a lot of the time people talk about executive dysfunction or executive function differences. Executive function is one of these cognitive domains. And you can measure it through a variety of different tests as well, which makes it easier for us scientists to kind of look at these differences between people in a way that is very easily quantified
00:14:05
Speaker
rather than subjective. And that's cognition, broadly. I mean, it might be worth just quickly saying what executive functioning, how you would define it.
Exploring ADHD: Cognition, Behavior, and Executive Function
00:14:16
Speaker
Yeah, so executive function encapsulates a lot of things. So maybe it's not the best example of a very clear-cut cognitive domain, but executive function relates to things like attention, whether it's sustained attention or kind of the ability to control attention itself across
00:14:35
Speaker
long periods of time. It also relates to abstract reasoning and planning. And you kind of have these different aspects of cognition, you know, playing out in various different ways across your development and across your life. And variations in these different abilities between people can actually impact life outcomes quite a bit. So for instance, if your executive function isn't
00:15:05
Speaker
you know, as precisely calibrated or maybe not so much in your control at certain points of your life, then you can find it difficult to plan appointments, let's say, or pay attention to really boring lectures at school, things like that. But then on the other side of things, a lot of people of ADHD experience hyperfocus. So that's a case of something that looks like executive function is really, really good.
00:15:35
Speaker
but actually it's just a different manifestation of it entirely. So that's such an interesting point. I'll go back to hyperfocus in a minute, but just, I mean, because executive function is going to come back and back, I think, because it's such an important concept. For me, it's like the X factor. When somebody is really, has got lots of really good skills, really good cognitive skills, but just can't get stuff done because can't get themselves together.
00:16:00
Speaker
That's executive function. And it's hard to get your head around, but it's almost that X factor that goes from the rest of your intelligence to actually getting stuff done. Do you see what I mean? The thing that greases the wheels to actually get stuff done. Anything that is in that is executive function. But can you develop that thought? Because hyperfocus is something that is so fascinating, this idea that people with ADHD, I mean, you can't cross it.
00:16:28
Speaker
Yeah, not so much anymore, but when I was in like year 10, I remember sitting down and just for two straight hours working on a piece of homework. Right. And I have never spent that much time working in a row and I just completely zoned in. Yeah. And I, yeah, I think I missed dinner or something. It was, it was insane.
00:16:48
Speaker
That is unheard of. It's an incredible trait to have. A lot of neurodivergent people can engage in hyperfocus, though not necessarily it will. That's the thing. So you don't really have control over it. And that's why we in the clinical world and in the research world
00:17:06
Speaker
consider it to be a feature of executive dysfunction because you don't necessarily have control over what topic you hyper focus on and when you hyper focus. And additionally, if you're hyper focused on something for an entire day, you might neglect other tasks, you might neglect going to get a drink of water or having meals at the right time or sleeping. And so it's basically something that
00:17:32
Speaker
varies a lot in neurodivergent individuals, but is also an indication that something's different about executive function. So that's such an interesting point, isn't it? It's often thought of as like a superpower, but if you can't control it, it's not much of a superpower. Yeah, I know I have a lot of neurodivergent friends and loved ones. And a lot of them have actually used the superpower in their careers and their hobbies. So they've gotten really lucky where the thing that they hyper focus on happens to be something that
00:18:01
Speaker
is profitable to them in some way. So maybe they're an artist, maybe they're a researcher and they have a flexible schedule anyway, and they can essentially fixate on something for a dozen hours in a row and produce something really wonderful. But let's say that you hyper focus on video games. Well, that's a bit different because
00:18:20
Speaker
I like video games. I gave up on one last night. It's not kind of universal. Could you not get past the zombies? I couldn't get past the zombies. I gave up in the right half. You're correct Tess. You've seen through it.
00:18:47
Speaker
And so you've talked, we've talked about cognition and really, that was really great. But then you talk about behavior. So when you say, when you say behavior, what does it mean? Because I think it means, I mean, it's such an interesting word because it's been so many different things to different people. Yeah. So of course, cognition, behavior are really intimately tied because you, you process information in your mind and then you act upon it in some way. And this processing can be conscious or unconscious, but your behavior is definitely observable to others.
00:19:17
Speaker
So behavior typically refers to the stuff that people can observe about you consciously and then take record of in some way. And these might be things like hyperactivity. So we can rate the extent to which we think another person is hyperactive if they're fidgeting a lot, jumping around. There are a lot of questionnaires that we use to assess children in particular on their hyperactivity that are based on traits like fidgeting in class.
00:19:46
Speaker
and having a lot of movement in their body and being impulsive and kind of not necessarily struggling to control their physical movement, but just having a lot of it. And then there are other behaviors too that are associated with ADHD. So we can talk about inattention as a behavioral trait. This is something that we can observe about someone.
00:20:14
Speaker
Attention is a feature of our cognition and involves information processing, but attention can also be thought of behaviorally. So someone can notice if we're behaving in a way that suggests that we're paying attention to what they're saying or paying attention when we complete a task. So the difference between cognition and behavior is that cognition occurs within a person. It's information processing that occurs in the brain, whereas behavior
00:20:42
Speaker
strictly kind of refers to things that we notice about other people, and then try to quantify so that we can look at interesting differences between people. It must be very hard to turn into a number though to quantify it, because it's so it's so subjective. It definitely is. And that's why we try to use big samples, because then we have more data, but then you still kind of run into this issue of
00:21:08
Speaker
you know, a person might behave completely differently at home versus at school. So if you've got a teacher to complete a questionnaire, it could totally conflict with the questionnaire completed by someone's parent. And even that's really subjective, because you're rating your child based on what you know about children. And that might be completely different from another person's experience of what children are typically like. And compare them to their siblings in an hour.
00:21:35
Speaker
The standard, you have to be quite hyperactive to be counted as hyperactive. Yeah, exactly. Neurodivergence occurs in families, so often you get families of everyone being neurodivergent, both parents, all the children, and so everyone kind of seems typical, even though on a population scale that might not necessarily be the case.
00:21:58
Speaker
Yeah. I mean, it's definitely genetic in our family, isn't it? 80% prevalence of ADHD, Tessie. That's true. 80%. Depends on if we're counting the dog. Okay, yeah, I can't work it out out of six. I'm not good enough at maths. So that's a really great introduction to the whole field, actually.
00:22:19
Speaker
But we need to sort of drill down to, do you want to do the first question? First question. So just for listeners, stress viewers, we're not going to go on so long, but I think it's really useful to have had that opening 20 minutes or so. But we're going to drill down to your research, what you're asking and what you find in your brilliant intro.
Neural Diversity in ADHD: Findings and Implications
00:22:44
Speaker
So in your research, what question were you asking?
00:22:46
Speaker
So in my most recent paper, which actually the online version just came out today in Cortex, which I'm really, really excited about, it's called exploring neural heterogeneity in inattention and hyperactivity. So to break that down, exploring neural heterogeneity, neural refers to brain. Heterogeneity means diversity. We're looking at neurodiversity in inattention and hyperactivity. So how are people's brains diverse?
00:23:16
Speaker
um, along a spectrum of these two traits. And we had a sample of about 300 children. So a very inattentive and hyperactive sub sample of our regular sample that we use in my lab from the center of attention learning memory, which by the way, I've got a brilliant acronym calm, calm, great acronym. So we've got the column sample. What I've done in
00:23:45
Speaker
The bulk of this paper is I've selected a sub-sample of kids who are particularly inattentive and hyperactive. So they have a questionnaire score on the Connors questionnaire that shows that they're kind of at the extreme end for these two behavioral traits. And then I use various different statistical techniques to look at different profiles of brain structure within these kids who are very, very behaviorally similar.
00:24:15
Speaker
So at this point, does that make sense? Yeah. How are you doing Tess? I'm okay. I mean, if you sort of, let's go back to cauliflower. Let's go back to cauliflower. So you look at the size of the cauliflower and you kind of compare, you do a graph of the size of the cauliflower stems versus how hyperactive someone is or isn't.
00:24:39
Speaker
So we did about the very beginning across a much wider range of our sample, so including people who aren't particularly inattentive and hyperactive. And we didn't seem to find anything about brain structure that coincides with the linear variation in inattention hyperactivity across everyone. So there's no specific part of the brain that
00:25:07
Speaker
determines across the entire population how inattentive or hyperactive people will be. So that's really interesting because there's lots of things in the kind of popular, not even the scientific, but sometimes in textbooks or sometimes in kind of talks about ADHD given by non-scientists and even by clinicians that, you know, the prefrontal cortex is particularly important and it's all about the frontal cortex. But I'm a bit skeptical about that, honestly, because
00:25:36
Speaker
Yeah, I'm also skeptical about that. I think that when someone is neurodivergent, it's a difference that occurs from the very earliest points of development and that can be seen across the whole brain rather than any particular region. So it might be the case that at the very early stages of development, for genetic reasons, for instance, someone
00:25:59
Speaker
developing in the womb and you have the very earliest version of the brain has a difference in their prefrontal cortex or in their visual cortex or in some other part of the brain. And that gradually as that person develops and they interact with the world, then that initial difference in one area starts to affect other areas of the brain. So by the time that they're heading off to nursery or they're in school and we see differences in their learning outcomes or their behavior,
00:26:29
Speaker
Basically, the difference that coincides with their ADHD or coincides with their neurodivergence is something that characterizes the entire brain rather than just one region that we can point to and say, aha, that's what's causing your ADHD. There's no such thing. We have to kind of look at the entire brain and look at how the properties of its connectivity vary rather than trying to outline a strict region that might be different.
00:26:58
Speaker
That is so interesting. That's such an important point, isn't it? So that's a negative finding, and I love negative findings in science. You know what I mean? We get very fixated by positive finding, but I love a good negative finding. What else have you found in terms of maybe positive findings or positive findings? Yeah, so we didn't find any singular component across our entire sample. So we thought, well, if it's a whole brain difference,
00:27:27
Speaker
Let's look at kids who are solely very inattentive and hyperactive and study the properties of their brain networks and specifically look at whether or not there are subgroups of brain network connectivity within kids who all share a common behavioral profile. So we took our sub-sample of about 200 kids who are very inattentive and hyperactive, and we ran a clustering algorithm. So we don't necessarily have to know what that is.
00:27:57
Speaker
A clustering algorithm looks for distinct clusters that are similar to each other within, within a sample. Um, and we fed people into groups. Exactly. Yeah. So it's just this, yeah. And, um, it methodically kind of goes through the sample. It looks at brain network data and tries to find subgroups, um, of, of brain network connectivity, structural connectivity. And here we can call them neurotypes.
00:28:26
Speaker
So we're looking for distinct neurotypes within a sample. Just to go back to my metaphor of sorting buttons, I'm not saying you're sorting the children by colour. I'm saying it's like, if you've got like a jar of buttons, you're sorting them by, you're finding different ways to sort them out.
00:28:46
Speaker
I think you saw the children by shape and color. It's a metaphor for buttons. I'm trying to kind of explain the, okay, we'll stick with clustering algorithms, shall we, Tex? I guess if we were to use our cauliflower analogy, let's say you have a huge barrel of like 200 cauliflowers.
00:29:11
Speaker
We're looking for groups more similar to each other than to whatever other group we select. And the really nice thing about this algorithmic technique is that we don't really have to make any assumptions about our data. It's very data driven, which means that we're not assuming any differences from the start. We're just kind of letting it run and seeing if it detects distinct subgroups
00:29:38
Speaker
within our sample. And what we found is really interesting. Please tell us what you found so we can stop talking. So within our group of very inattentive and hyperactive kids who were also similarly matched on all the other behavioral questionnaires that we gave to them, we found two subtypes of brain structure. Okay, so these kids are behaviorally pretty much the same. If we had them in a school environment,
00:30:07
Speaker
They would get the same types of behavioral reports from their teachers. If we took them to a clinical environment, it's very likely that they would be given the same range of diagnostic labels. However, there are two brain profiles and these weren't determined by age and they weren't determined by gender. So that's really interesting. And this led us to question, okay, so what actually differentiates these brain subgroups or neurotypes?
00:30:34
Speaker
within a sample of kids who are highly inattentive and hyperactive. And it turns out that what they differ on is their cognitive ability. So while they didn't differ on their behavioral traits, they exhibited differences in their scores on visual spatial reasoning tests. So going back to what we know about cognition, visual spatial reasoning is a type of information processing in the brain that takes sensory information from the visual sense
00:31:04
Speaker
and kind of tries to think spatially about the world. And it turns out that this type of measure also tracks the extent to which a person can engage in complex abstract reasoning. Things like mathematics, planning, just realms of executive function that we're probably familiar with in the more colloquial sense. So we have
00:31:28
Speaker
Inattentive hyperactive kids, two brain subgroups. One of them is slightly better at cognitive tasks that measure visual spatial reasoning than the other group. And that in itself is really fascinating. So we're kind of finding two brain subgroups of people that might get an ADHD diagnosis. They differ in their cognitive ability. But then when we actually looked back at their brain networks and tried to figure out what would actually cause this initial split,
00:31:58
Speaker
what differentiated the brains in the first place, primarily it's a brain network measure called communicability. And what communicability refers to is kind of the efficiency with which distinct regions of the brain network as a whole, the whole brain, facilitate information flow. So we don't have to get into the nitty gritty details, but
00:32:24
Speaker
We computed communicability values for each of the brain regions within our connectomes, within our brain networks, and found that these two groups are primarily differentiated by that measure. So there is a connection between brain network communicability or information processing and performance on cognitive tests, where the group that had higher cognitive test scores
00:32:54
Speaker
also had higher communicability within their brain networks, allowing efficient information transfer. So it's kind of a novel finding. The better connected the different bits of the brain, the better that the person was at solving these abstract problems of the type that you see in school in a lot of education. Yeah, and not necessarily more connected either, just sort of more efficiently connected.
00:33:21
Speaker
It's like if we think about a network of trains or roads, you can have a lot of connections, you know, in your railway system. But that's not necessarily efficient. It's certainly not. But if you have, if you have big hubs of activity, like King's Cross St. Pancras, or Newcastle or York, where a lot of trains go,
00:33:46
Speaker
and they all stop there and allow people to get on and off and connect to other destinations, then that's a good indicator of communicability within a network. Okay, good example. I don't spend enough time outside of where I lived. Clapham Junction? No, you've probably never been to Clapham Junction. It's one of the busiest stations in the country and it's tiny. Anyway, it's a very good example of very small space and lots and lots of stuff happening.
00:34:16
Speaker
Okay, sorry Tess. Just doing my job. I don't understand about trains. Okay. Why should you understand about trains? So the two different groups, I suppose my obvious question is, does this make a difference to their outcomes? But you might not have looked at that yet.
00:34:39
Speaker
We don't quite have data on that, or at least I haven't probed enough to necessarily assess that about long-term outcomes. But you would expect that if you have worse cognitive performance on certain reasoning tasks or tasks that are really closely associated with things like mathematical ability, planning, executive function, then you might gradually come to experience worse academic outcomes.
00:35:10
Speaker
And that's interesting because these kids in our sample, again, are behaviorally comparable. So they behave in the same way. And we can assume that if they went into the clinic, then they would all be given a diagnosis of ADHD based on their high levels of inattention and hyperactivity. But one subgroup experiences significantly worse cognitive test scores on these specific visual-spatial reasoning tasks than the other one.
00:35:38
Speaker
Both are a bit lower than the age expected average, I should note. So both of these, in the sense of hyperactive subgroups, actually have lower cognitive test scores than what would be expected for them at their age. But one performs significantly worse than the other. And that might indicate that those kids need more support within school and beyond throughout their learning, basically, in order to feel
00:36:05
Speaker
like they can regulate their behavior and actually manage tasks well. And it's not really considered in the literature of ADHD. So what we know about the current classification of ADHD is that there's an inattentive subtype, a hyperactive subtype, and a combined subtype.
Critiquing and Rethinking ADHD Classification
00:36:23
Speaker
That's how it's classified within, for instance, the DSM, the Diagnostic Statistical Manual for Mental Disorders.
00:36:33
Speaker
But this isn't what we saw in our sample. Inattention and hyperactivity were highly correlated. So we're getting more of a combined subtype, if you will, across everybody. And what differentiates kids within that overall group is their cognitive ability, not whether they're more inattentive or more hyperactive. And my reasoning towards the end of this paper, if anyone listening gets a chance to read, is that
00:37:01
Speaker
we should be focusing on data-driven approaches that allow us to learn things about these types of kids to better provision resources for people that might need it. So for instance, those struggling with their cognitive ability at school, because that's more likely to have effects on their learning outcomes and also on their wellbeing and how they feel about their own ability later on down the line
00:37:29
Speaker
than this rather arbitrary distinction that we currently have between so-called inattentive only and so-called hyperactive only subtypes. That's so interesting. And it sort of shakes. I mean, probably most people watching slash listening wouldn't really care about that. But clinicians would just like to shake their, rock their world a little bit to have that distinction taken away. Although I kind of agree that a lot of the time it doesn't really matter. I'm aware that some people that I have
00:37:59
Speaker
given one or the other two might be listening as well. So it's still kind of, you know, sometimes it's useful anyway. So what does this mean for people looking after ADHD people?
00:38:17
Speaker
What this means is that we shouldn't just look at behavioral traits, I guess. And we also shouldn't just care about someone's diagnostic label, because there are a lot of inequalities on who has access to a diagnosis. There are enormous waiting lists to be able to get a diagnosis. And not everyone kind of has access to the knowledge that they would need to even seek a diagnosis in the first place.
00:38:44
Speaker
As well as this, a lot of women and girls are often under diagnosed or misdiagnosed with something other than ADHD, even though they present with the clinical symptoms simply because of bias within the system and not enough research on women and girls with ADHD. So we shouldn't just be looking at someone's diagnostic label that they may or may not carry.
00:39:07
Speaker
We should be looking at their behavioral traits and also their cognitive ability if we're to get a good holistic picture of what a person is like and what their outcomes might be. So yeah, takeaway points would be don't fixate too much on a person's diagnostic labeling. It turns out that's pretty arbitrary and laden with bias.
00:39:29
Speaker
look at their behaviour and don't just look at behaviour and assume that behaviour determines everything. There may also be really fundamental, important cognitive differences that drive how a person interacts with their world and learns and comes to feel about themselves and also their ability. Yeah, I think for me as a clinician who does these assessments, it sort of
00:39:55
Speaker
Well, it reminds me of the importance of the cognitive aspect of the assessment. So we do do routinely some cognitive testing on these kids. And sometimes I think of it as just, well, making sure that they don't have a learning disability, but actually it's more than that, isn't it? What your research suggests is that it's independently important to know what their reasonability is.
00:40:19
Speaker
in this, particularly in the kind of video spatial abstract kind of way for their management, particularly in schools. Yeah, because if we look at general cognitive ability distribution, so things like IQ within the general population and the ADHD population, you don't actually get that much of a difference. So
00:40:43
Speaker
People who have ADHD or autistic exhibit a similar distribution of general intelligence as, as the rest of us, where, you know, the average is 100 and you have kind of a tapering down the sides of the distribution of people who score lower and people who score higher.
00:41:04
Speaker
But general cognitive ability doesn't necessarily capture subtypes of cognition. So things like language processing, visual spatial reasoning seems to coincide pretty strongly with IQ, but it doesn't determine the full picture. And if we reason that a person has a general cognitive impairment or a learning disability,
00:41:34
Speaker
versus they don't have this and they're fine, then that's a very reductionistic picture to paint because there might be specific things that they struggle with and other things that they don't struggle with. And we have to be selective about what kind of support we offer. And I know for teachers, it's really, really difficult now to be able to find resources and time to be able to do this kind of specific provisioning. But what we're hoping is that we can
00:42:02
Speaker
fuel research for the future and also kind of contribute to trans-diagnostic research right now, research that doesn't rely on people's diagnoses and instead just looks at cognitive and behavioral traits in order to inform better practices with the hope that one day people will be able to receive more specific kinds of care and support. Okay, so I mean, shall we move on to the next question?
00:42:28
Speaker
Yes, we sure should. So what does this mean for ADHD people themselves? I guess my takeaway here would be that there's a lot of diversity even within ADHD. Even if we're not just talking about behavioral diversity, there's significant cognitive diversity and even brain diversity. So we can look at people who seem to behave in the same way and
00:42:55
Speaker
We can't even assume that they have the same type of brain profile. And I think that's really interesting because when we talk about neurotypes and neurodivergence, we use these words that kind of suggest that there are types of brains that always yield a certain kind of person. And that's not really the case. So we have to be accepting of diversity within these
00:43:20
Speaker
sub-communities and not necessarily make any assumptions about who's the same as anyone else that could hinder research and also hinder efforts to bridge gaps in understanding and foster solidarity among people who are neurodivergent. So that's very interesting the point you made about fostering solidarity
00:43:40
Speaker
Are you suggesting in a way that if we just cling on to, I'm ADHD, you're autistic, he's got, or she's got dyspraxia and we're in different camps, whereas we should be more thinking about ourselves as actually the variability within those camps in a way. Yeah. I mean, I was talking to a friend today, who is autistic and also has ADHD about a recent encounter that she had
00:44:07
Speaker
where someone said to her, you can't possibly be autistic, you have ADHD. And I said to her, well, you should have told them that there's a 30 to 70% co-occurrence rate between autism and ADHD. And I think that's really important to remember that these categories, these diagnostic labels, they're not necessarily, you know, set in stone or fundamental in some special way.
00:44:34
Speaker
They're just there for diagnosticians to be able to make good choices about what kind of support a person might need. They're not natural groups that exist out in the world in and of themselves. There's a lot of overlap. The boundaries between these categories are really fuzzy. And we can find a lot more commonalities within neurodivergent people than necessarily
00:45:00
Speaker
commonalities within specific diagnostic labels. So I suppose just to kind of unpick what that means, because that's a really profound point, isn't it? That neurodiverse people are often more similar to each other. So like two neurodiverse people are often, they may be quite similar to each other, but have different diagnoses.
00:45:23
Speaker
And two people with the same diagnosis can be radically different to each other. I suppose that's in a way. And there's a sort of huge variation within the neurodiverse population, but then another set of variation between the neurodiverse population and the neurotypical population. So there's this kind of complex, complex web of differences and similarities going on. Human diversity is everywhere. We can see it at every level, including within the community of neurodivergent people.
00:45:51
Speaker
So when we look at diagnostic labels, I think we should kind of take them with a grain of salt and realize that as a whole, if you're neurodivergent, if you experience certain behavioral differences from someone that you consider neurotypical or cognitive differences, then it's very likely that someone who has a different diagnosis than you or no diagnosis at all is perhaps very similar to you nonetheless.
00:46:20
Speaker
And we should be looking scientifically at these problems with less of a priority on diagnostic labels. So I mentioned previously that my research uses a trans diagnostic approach and trans diagnostic means outside of diagnostic boundaries. So we don't recruit participants on the basis that they've been diagnosed with ADHD or diagnosed with autism. We just have a big cohort of kids. We give them all tests and we compare them on
00:46:50
Speaker
behavioral and cognitive test scores rather than grouping them in a pretty arbitrary way based on diagnostic labels.
00:47:01
Speaker
I mean, really having a go at this diagnostic label stuff. I just thought I do. Hang on. Is my job just a complete waste of time? No, that being said, I should really say that diagnostic labels serve a purpose, right? They're not fundamental distinguishing sort of barriers between people that are perfectly characterized in every way. But if someone receives a diagnostic label of some kind that can help them,
00:47:31
Speaker
then it served its purpose. And our job as scientists is to feed into the clinical models that we have and perhaps refine our diagnostic labels so that they can be more useful. So I'm fully behind the application of diagnostic labels. And I think that they're necessary in order to allocate resources efficiently, for instance, which is like a huge part of medicine. It's just that perhaps the specific labels that we have now need a bit of a reboot
00:48:00
Speaker
based on data-driven science. And that's kind of what we're hoping to do. Absolutely. Okay. I mean, I completely agree with that. I was slightly pulling your leg. Do you want to do the final question? Yeah, yeah. So what's your next question once you're all finished up with this?
Future Research Directions and Contact Info
00:48:18
Speaker
So my next question has been looking at resting state functional networks. And that's been the second chapter of my thesis, but my current project, which I think is
00:48:29
Speaker
Also really interesting is looking at brain network dynamics along the spectrum of inattention and hyperactivity. So we're having people go into a different kind of scanner called an MEG scanner, which stands for magnetoencephalography that measures electrical impulses at the scalp. And I'm looking at how different patterns of firing across brain networks at rest
00:48:59
Speaker
might relate to inattention hyperactivity traits. So that's forthcoming at the moment. We're using a lot of very interesting machine learning and statistical techniques to sort of learn the structure of the data and then compare it between people on the basis of their behavior. So it's another way of looking at this population and seeing if they fall into different categories. I'm not going to try the button metaphor again, that was a terrible
00:49:28
Speaker
Okay well I mean that's fascinating and you must come back and talk to us when you've got some more amazing insights. Thanks so much for having me. If people want to sort of find, I mean we'll put, we'll try and find a link to your Cortex paper and put that in the show notes slash description.
00:49:48
Speaker
If people are looking to follow your work, I can't remember if you go on Twitter or not, because I met you in person. So people can always get in touch with me over email. If you just look at the Cambridge neuroscience web pages, my name is Natalia Zoroptova. There's only one person in the world named like I am. At least who works at Cambridge. You can find me there.
00:50:17
Speaker
And yeah, otherwise on social media, I don't go on Twitter very often, but sometimes I do for research purposes. It's at neuro underscore theologia. So like biology, but with an I8 at the end.
00:50:34
Speaker
That's very nice. That's a very classy Twitter handle. I like it. I don't think it's possible to have a classy Twitter. I think it is. And I think you've managed it. I think if there's anything that can be the closest to classy, it's possible to be with a Twitter handle. That's it. OK, fine. Well, thank you very much. There you go. All right. Well, thank you very much, Natalia. We've reached the point of the podcast recording when Tess and I start to ramble. So that's the always the time.
00:51:03
Speaker
rails come off our rambling so it's usually the time to stop so thank you very very much for joining us today thank you so much and goodbye okay so there was the interview there it was we won't do too much chit chat because we've already had quite a long intro and you're tired and i'm tired
00:51:27
Speaker
Hey, that's no excuse. Always stay on the grind. But we hope that you enjoyed that and please do let us know via Instagram, Twitter or the website via ADHD UK what you thought and what questions you have and actually what topics you would like to cover in future because we can find somebody who's researched it, ask them to come on and ask them questions about it. That's the genius of this format.
00:51:55
Speaker
Alright, I will speak to you later. See you in another week.