Ep. 211: More Than Words: The Neuroscience of Human Voice

00:00:00: Welcome to EANcast, your weekly source for education research and updates from the European Academy of Neurology.

00:00:14: Hello!

00:00:15: And welcome today at EAN Cast Weekly Neurology.

00:00:18: My name is Elisa Canu.

00:00:20: I am a neuropsychologist and researcher at the Saint Raphael Hospital in Milan currently serving as co-chair on the EAN scientific panel on higher cortical functions.

00:00:32: My research focus on the structural and functional correlates of cognitive and behavioral features in neurodegenerative disorders.

00:00:40: This month's topic is The Interaction between Language & Motor System, And In todays episode we will talk about something like related to more than word – the neuroscience of human voices!

00:01:02: She is a professor of Cognitive Neuroscience at the University College London, UCL.

00:01:08: And she served as director of UCL institution of cognitive neuroscience where she's also head of this speech communication group.

00:01:18: Her research investigates the cognitive neurosciences of voices, speech and laughter particularly speech perceptions which production vocal emotions in human communication.

00:01:32: Welcome Professor Scott and thank you for joining us today.

00:01:37: Hello, Thank You very much for your kind invitation!

00:01:43: So professor... For many years the relationship between the motor system and speech has been at a centre of an intense scientific debate.

00:01:54: From your perspective what are most important advances that have changed?

00:02:00: our understanding of how speech perception and speech production interacted?

00:02:09: I think one really, big change was developments in the nineteen nineties where people started getting better neuro anatomical models on how primate hearing works.

00:02:19: And that showed us as an individual system there's not just one thing happens during perception.

00:02:25: you've got this streaming information As exactly the same as in a visual system and you've got this kind of recognition pathway is distinct from sensory-motor interaction pathway.

00:02:37: And potentially there's more pathways than that, but these are clear points to sort of map out different aspects of speech perception network.

00:02:46: so when your listening to speak part what happening here is listening for meaning... ...and part of whats'happening is listening to sound that u could make!

00:02:54: and the sound you're probably about to make, because usually use speech in a conversation.

00:02:59: And then I think... In parallel with that we also now have much better understanding of the complexity of motor control networks involved.

00:03:10: well, motor control in general More work has happened here is happening in the manual system than in the articulatory system Because it's easier to study other primates.

00:03:20: But if get this profile as motor Motor acts become more complex.

00:03:26: So if I go to London Zoo and look at the squirrel monkeys, they have hands that look a bit like my hands but use them very differently.

00:03:33: They can't move their fingers individually for example And it affects how they interact with objects.

00:03:39: What you find is roughly as you look across more and more complex manual control in primates what we found Is a more complex pattern of motor control and that pattern on motor controls involves sort overlapping parallel systems that seem to be involved.

00:03:54: So we've got primary motor cortex, but we also have got supplementary motor cortex and pre-motor cortex all involved in actually kind of direct control off the

00:04:02: hands.".

00:04:04: That seems a very good reason for thinking something similar is likely happening with motor controlled articulation in humans.

00:04:12: We should look at complex overlapping parallel motorsystems.

00:04:21: David Ostry has been talking about a lot in Montreal.

00:04:25: And then that kind of makes it all more interesting when you start to think how these two very crudely, well the systems we think are being separate interact and of course... We know perception is absolutely essential for production to occur.

00:04:42: so if even mild hearing loss will affect your ability to acquire speech because when you are speaking, part of what you're doing is your guiding.

00:04:51: What it sounds like and also what it feels like with a somatic

00:04:55: sensation.".

00:04:57: And David Ostry has argued from that perspective if should think apart to the brain-like primary motor cortex as being sensory cortex because he's getting so much input from vision and hearing and touch.

00:05:09: So I think this really interesting way thinking about massive interaction between perception production in ways where essential for production.

00:05:21: You can almost think of the brain, job with a brain as perception and sometimes you're perceiving what's out there in the world and rest of time your are perceiving that which is doing.

00:05:29: so I think it has been really helpful And also starting to think because brain areas involved similar tasks.

00:05:40: they might not be doing same thing.

00:05:41: For example you find primary motor cortex responds when hear sounds But that doesn't necessarily mean it's involved in recognising those sounds.

00:05:52: It could be part of the sensory motor preparation or tracking which is an argument we've made.

00:05:58: Now, as you say these are still massively under debate but I think something really helps being able to take models from other primates and actually use them to appreciate how complex they systems are happening in lots of different ways, basically.

00:06:19: And how would you briefly describe the current role... ...of the motor system?

00:06:26: In understanding spoken language?

00:06:29: and what evidence has been most convincing in shaping your view?

00:06:32: I

00:06:34: think that the most convincing argument is strongly involved with representation of meaning.

00:06:44: So we know that when the brain represents meaning, it does it partly in an abstract way.

00:06:51: There do seem to be parts of the brain that represent semantic information In a kind of very abstract hierarchical way.

00:06:57: so the anterior temporal lobes seemed to be important for That.

00:07:00: but We also know that's not happening as not The only place where information is stored?

00:07:04: So soon if there's any kind Of embodied information so for example vision information associated with that word or auditory information.

00:07:12: You will start to see the semantic system drawing those regions in, so you get activation and visual parts of your brain when you hear a word that's highly easily imaged like love... And much less so for words that are abstract than its representation or love!

00:07:28: Within this framework there is an important role for motor areas representing verbs.

00:07:35: Friedman Paul van Muller showed us if we listen towards kick, lick & pick which are all referring to actions, but their action is made with different parts of the body.

00:07:44: You see different parts in the motor system recruited as part that kind of embodied representation of

00:07:50: knowledge.".

00:07:52: There's a persistent belief that primary motor cortex is involved in direct decoding speech and I think it's harder for patients who have severe problems with speech production.

00:08:04: don't have straight down problem understanding speech.

00:08:11: They don't often have these brain areas compromised and they are still able to understand speech.

00:08:15: Now, they can have difficulty doing some complex phonetic tasks on the speech spitting up a sound into phonemes for example.

00:08:23: And there is lot of evidence that when you're doing that When your mapping between sort-of word in it's phonemic elements That does seem require level segmentation which starts recruit primary motor cortex.

00:08:37: And I think that's interesting because we know when children are learning to read, even if they're learning to write a script like Chinese which is not made up of letters it really helps children be able break words down into their phonemes.

00:08:58: That seems an important pre-state too acquiring the ability Along with other kind of.

00:09:08: charlotte jackman was argued.

00:09:09: other kinds like verbal working memory tasks really require the speech perception and a speech production system to work together very closely.

00:09:17: So i think you've also got this kind of added value for what u get from how speech perceptions speech productions systems interact in that they can lead.

00:09:25: today, there's no segmentation skills.

00:09:27: it mean you can read and they leave to the sort of representation off without words on your head without having say them allow or have to keep listening to them where you can do working memory tasks on the words and maintain something in working memory before writing down that kind of thing.

00:09:45: Do a maths problem with your head, so i think thats an enormous added value for having these complex speech perception networks really interesting.

00:09:57: things can start happening from other cognitive domains when they interact?

00:10:05: On this repose, your work argued that speech production relies on a distributed network rather than in single-speech area.

00:10:15: How has our understanding of Broca's area changed over the years and what role do you think it plays today?

00:10:26: That is very good question!

00:10:28: I think one thing we learned early with Functional Imaging Studies was classic Broca areas posterior third of the inferior frontal gyrus on left.

00:10:39: That is really recruited for a lot different tasks are things that even aren't apparently linguistic in any way.

00:10:47: although maybe language, may be inner thought.

00:10:51: it's kind of helping you do some of these tests.

00:10:54: still it's very innocent and not just doing speech production for sure.

00:11:00: It is clearly involved with speech production.

00:11:06: It is also the case that if you test with Brock as aphasia, they will have problems that aren't limited to speech production.

00:11:13: So it's clearly quite an important hub.

00:11:17: Peter Haggard in Nijmegen he was really interested in this sort of like kind of cognitive element part of much wider distributed system for control and executive function And its prefrontal cortex and beyond.

00:11:36: So it is definitely in brain areas that would well plausibly have not just a linguistic function, you know the frontal cortex often as very generalist parts of the brains.

00:11:46: so we'd expect that.

00:11:49: What I think personally does seem to be... Nina Dronker showed pretty convincingly It's not doing articulation if you have lesions into anterior insula profound problems of being able to articulate.

00:12:10: Whereas if something's constrained just to Brokers area, the lesion itself is just constrained to Broker's area.

00:12:16: people show transient mutism and then often recover some speech production.

00:12:21: that's JPMore work.

00:12:23: so what you do seem to need something bigger for classic Brokers aphasia?

00:12:26: You do see two damage not just the cortical area in the posterior third or inferior frontal giles but also What it's connecting too.

00:12:34: And I think that interesting thing about I would probably say it's not doing the direct control of articulation, or even necessarily planning.

00:12:47: But then I think planning is probably important and some sort kind of higher order control.

00:12:52: but in that its working with... It has to be working these overlapping systems you know in premotor cortex and in the supplementary motor area for example.

00:13:04: And also we got this really intriguing finding years and years ago.

00:13:08: This is work by Catherine Blank that showed, you know what people doing a speech production task in the scanner?

00:13:13: You get broker's area which she'd expect to see.

00:13:16: if you take patients who have had brokers aphasia stroke and recovered speech production when you scan them... ...you'll get right.

00:13:23: broker's are activated which it interesting to say any make sense because of recovery function is homologous brain area.

00:13:31: but do actually look at what happened in my blockers area when people, the neurotypical people being scanned.

00:13:37: It was being suppressed.

00:13:39: it has been actively unactive.

00:13:41: you know he's really been showing suppression.

00:13:44: and there is something interesting that because as soon as you start changing this voice task to your using so get people instead of their talking awesome to sing.

00:13:55: You started seeing lots stuff happening in right brokers area said there's something very interesting.

00:13:59: they're having a kind dynamism of the left and right, how they are talking to each other.

00:14:04: So I think there's a lot more to know about that.

00:14:07: Nice!

00:14:09: And one of the central ideas in your paper is the distinction between the auditory work and how pathways... How do these two systems cooperate during everyday communication?

00:14:28: So I think that so you've got this kind of these streams are processing what i talked about in the primate brain and one's running forward from primary order to cortex down The temporal lobe, And the other is running back up into sort of parietal cortex.

00:14:41: And that that rostral stream that anterior going stream That's the recognition pathway on this.

00:14:47: more the cordle stream thing running backup Into the throttle load?

00:14:50: That's what we think off as a sensory motor pathway.

00:14:54: I Think normal conversation like what we're doing now what you get is, we take turns when they're speaking to each other.

00:15:02: So he don't just talk and understand each other We also align our voices And we start to pick up on the rhythm of the other person's speech... ...and we started picking upon their breathing.. ..and we starting to pick it up in pitch for this speech.

00:15:14: In another words you align your voice with a person that are talking too as well.

00:15:18: listen them.

00:15:20: I think conversational speech The sensory motor pathway is important.

00:15:25: obviously when you're talking because it's helping control that we know this.

00:15:28: When your listening i think it's a sensory motor path way but he's picking up on the rhythm and pitch and the sort of, in fact breath pattern at the other speaker while you are understanding what they saying in that rostrum recognition pathway and there working together to mean that u are able too take over your turn minutes your turn to speak or indicate that you'd like to speak pretty effortlessly, if you look at how closely people time conversational speech there are very rarely long gaps between sentences and people very barely overlap each other.

00:15:59: And that to me looks like the motor system is involved in that kind of timing profile.

00:16:04: so I mean there were people who would wildly disagree with on this.

00:16:07: but i think thats what's happening.

00:16:08: So it's not that recognition network only activated when your listening somebody?

00:16:13: If you're talking them then sensory motor stuff probably always there.

00:16:17: Nice!

00:16:18: Very interesting.

00:16:19: And about speech in social communication.

00:16:26: In your work, you argue that the speech is much more than language.

00:16:31: it also conveys identity emotion and social meaning.

00:16:38: Why do we think neuroscience as traditional underestimated these non-linguistic aspects of speech?

00:16:48: I suspect because Aphasia when somebody has a problem producing speech or understanding speech, it's so devastating.

00:16:57: You can completely understand why.

00:16:58: that is the problem of language or perceived classically as a problem with language.

00:17:02: and again... As soon you encounter someone talking to you are aware of their words they're saying?

00:17:08: Or not!

00:17:09: And what we engage in here Is business of language.

00:17:16: I think we've just kind of not paid enough attention to the fact that as soon there's somebody talking, theres a voice.

00:17:21: There is no speech without someone or something talking and its an intensely social cue.

00:17:30: Theres alot of information in that talking voice.

00:17:33: people will try read all sorts of information get all sorts out even if it wrong You know.

00:17:40: so i few times because sometimes do a bit of radio in the uk and few times have met people who would only heard me on the radio and then always surprised at how old i am.

00:17:49: I sound young to them i sound younger than i am but that we're all doing it all the time because there's so much information about somebody.

00:17:56: when they are talking as soon as their talking with getting words they say what were also getting information about whether their male or female, Um, we're getting information about whether or not they are unwell because that will often affect the voice.

00:18:13: We've got information about their mood Because there emotional state will affect their voices and probably everybody's had experience of talking to somebody on the phone And then going no I'm NOT angry!

00:18:23: You think?

00:18:24: I think you were a little bit angry But your also get information about Their origins.

00:18:31: So with vocal learners when learn language from people around us who teaching us to speak.

00:18:38: They don't do it explicitly but we learn from them and that means, not just the words they're saying but also how they talk.

00:18:44: so you've got geographical origins are in your voice And also your socioeconomic status.

00:18:51: So... In the UK there's something called TH fronting.

00:18:59: That being said instead of month or throw You say month Or throw.

00:19:07: And as soon you start, if we just take recordings of somebody's voice and you edit it such that instead of saying I'll throw that next month.

00:19:15: They're saying i'll throw the next month people will rate that person is being less employable now?

00:19:21: You know nothing about a person from how they speak.

00:19:23: then literally tells me Nothing.

00:19:26: but be people.

00:19:26: this make an automatically notice assumption because It Is The Marker Of Lowest Lowest Social Status.

00:19:32: What It's More You Know It's Not A It's not a posh way of speaking.

00:19:37: That's something that people can be very blind to, kind of assumption.

00:19:43: And also voice is a very affiliative and voices are something but change.

00:19:48: so our voices do change all the time.

00:19:50: they're changed over long span over lifetimes But it will still change minute-to-minute depending on who you or where your talking too.

00:19:58: So I come from north England.

00:20:00: when i go back to the north of england my accent changes completely because im showing affiliation with people around me and then in london, come tree bumpkin.

00:20:15: It's not particularly a decision but it is very common thing that people do.

00:20:22: so you like somebody more will change your voice.

00:20:26: When I talk to my mother on the phone, i sound exactly like her for quite a long time afterwards.

00:20:31: My husband can tell if i've been talking with him because many things about our lives are very different.

00:20:36: but you know that's how much i am like and thats something people do great deal.

00:20:45: so there is some sort of social affiliate element in voices.

00:20:50: i think that's really interesting and again sort of missing from our.

00:20:54: if we just thinking about a speech we miss that social emotional dimension.

00:21:00: So so interesting.

00:21:02: and what about patients with aphasia?

00:21:06: often they report the day no longer sound like themselves, even after recovering much of their speech.

00:21:17: do you think preserving vocal identity?

00:21:21: should become an explicit goal of speech rehabilitation or treatment.

00:21:28: I do agree.

00:21:28: it's really something worth taking seriously, i've heard a patient describe aphasia as being like identity theft because even if you make good speech recovery chances are that you will not sound the way.

00:21:44: a specific form of speech apraxia which is called foreign accent syndrome and it just means to your you basically have a foreign.

00:21:52: And acts a dyspraxial speech or an apraxxious speech.

00:21:55: that two your fellow countrymen happens to make me sound like you are speaking with the foreign accent because she's not actually speaking for the foreign accident, and she carried around with her cassette player on tape when should be on the radio input in part competition few years previously and she would let us into that Before you had a conversation with us, so you knew what she should sound like.

00:22:17: She said that's me That's-that's what I should sound Like.

00:22:20: and of course that voice was lost to her.

00:22:24: And i think we Again understandably speech and language therapy focuses on getting the speech sounds right Because you know speech really matters in getting The details matter.

00:22:35: but But people it doesn't Really get to that loss Of identity?

00:22:40: How can You even if you Can't ever restore that and it may not be possible.

00:22:46: Can you, how can we support people in dealing with a loss of identity?

00:22:51: In a very profound way!

00:22:54: Very nice... And one of the most intriguing ideas on your papers is increasing involvement right hemisphere regions during vocal modulation, joint speech and singing.

00:23:12: I'm a fan of the right hemisphere!

00:23:17: And what do you think is the fundamental contribution to voluntary vocal production?

00:23:29: I'm not certain that can give you a good answer.

00:23:31: But exactly as you say, and I briefly referred to it earlier... As soon as you get away from just speech You start seeing much greater contribution of the right frontal lobe in particular but also temporal lobe during speech production or vocal production.

00:23:45: That's all sorts singing.

00:23:49: When we had people trying to impersonate other people We started saying It's very interesting because it almost makes me think that singing and we are starting to move in this direction, singing which seems to give you much more bilateral activation.

00:24:08: Maybe maybe that is the starting point for volitional motor control of The Voice?

00:24:14: We were singing before talking but instead thinking if well we've got speech or song... ...we should have thought about what our voices might be for potentially.

00:24:24: And speech is a really weird version of that, where you kind of don't do the musical stuff as much.

00:24:31: Although we always speak with rhythm and melody there's no.

00:24:33: We Don't Talk To Each Other Like That.

00:24:36: It Would Be Strange.

00:24:37: So There' s Always A Music to Speech But You Don'T Get That Kind Of Repetition In The Structure That You Get In Song And Then You Get A Different Kind Of Vocal Control.

00:24:45: so I think maybe it's speech.

00:24:47: thats an odd thing because its strongly lateralised certainly in terms of the frontal areas, and maybe that kind of suppression of brokers I was talking about.

00:24:59: Maybe it's deliberate to stop you from

00:25:00: singing.".

00:25:02: That is just a guess.

00:25:03: but we might need our vision for what their vocalisation network is doing.

00:25:11: why its there?

00:25:12: We may have to sort of unstick ourselves assuming they are all about speech.

00:25:18: if the origins or voice line something more musical that gets us to speech, you know?

00:25:26: That's sort of where I'm starting to go now.

00:25:29: So from that context as soon as you have any kind of musicality in sound and it doesn't have to be vocal the right hemisphere starts will be dominant.

00:25:43: so sounds like pitch variation.

00:25:47: It likes sounds are longer rather than shorter.

00:25:53: It likes all the other kind of non-verbal information in their voice, it likes emotion.

00:25:57: Not that left doesn't but its right seems to like a bit more... ...it's really involved with vocal identity which is not determined solely by pitch.. ..but pitch is really important for vocal identity.

00:26:07: so there are lots of things we're sort of saying as soon you zoom out and say just get ourselves away from words or phonemes they're very important.

00:26:15: and grammar Which have our left bias?

00:26:18: There something kind of like this, it's almost going to be the structural elements that these phonemes and words can sit on.

00:26:26: That is where music matters!

00:26:30: Nice... And you did a lot work also with Latha, and Latha is often considered one of the simplest human vocalisations.

00:26:47: yet your work shows It engages remarkable sophisticated neural mechanisms.

00:26:55: What makes laughter such a powerful model for studying social communication?

00:27:05: That's another very good question, I mean i went into this because i was looking at non-verbal expressions of emotion in the voice.

00:27:11: you know if your really frightened do scream You don't just say why am frightened.

00:27:16: And that was what I was looking at, and i started to look more positive emotions as well as negative.

00:27:20: But I included laughter because thought it's interesting when something is funny or amusement.

00:27:29: There was a psychologist in America called Robert Provine who said you are much more likely to laugh with someone else than if on your own... I slowly over the years came to realize he was right.

00:27:48: We do laugh when things are funny, but most of time we're laughing for a host of other potential reasons.

00:27:55: so if you kind of zoom out and look at laughter in mammals... Mammals laugh while they're playing.

00:28:00: They laugh where their being tickled.

00:28:02: It's physical joyful fun activity that seems important in bonding And course learning through play And humans do both those things!

00:28:11: We laugh on our tickles But we also laugh in this host of other ways.

00:28:18: so humans are the only animals that laugh contagiously.

00:28:21: we can catch laughs from other humans.

00:28:24: And contagious behaviors a quite common nature but only human show contagious laughter and we also love, uh... In a way it's very kind of gives away about social setting where i said you laughed more when your with people who know You actually laugh differently when you're with people that, versus laughing with strangers.

00:28:43: People can hear the difference in that and we will laugh communicatively.

00:28:48: In a conversation, people use laughter to show they understand... ...they recognise or remember the same event.

00:28:54: In fact, Provine found at any one point of time someone was talking Is the person who laughs most.

00:28:59: so that's what people are communicating.

00:29:02: I'll try to get people show they remember they understand it.

00:29:05: very strong communicative signal and people use laughter too.

00:29:11: deal with stressful situations trying deescalate a stressful situation, and people will use laughter to cover up other emotional states.

00:29:22: I was listening to a podcast awhile ago where women were talking about the dog that passed away and she started crying.

00:29:27: And she laughed, to get herself out of the car... That's very common use!

00:29:31: In fact it could be doing all those things at once.

00:29:33: but also we do laugh when things are funny so.. The same laughs might be friendly contagious.

00:29:42: showing understanding is making everybody feel less stressed and always contributing to feeling closer in your social bonds.

00:29:50: So I think it's a, It really interesting that we drop into this ancient mammal vocalization.

00:29:56: Really precisely in conversational speech because thats where most laughter lives is in the conversation.

00:30:00: That what humans do when they're together.

00:30:02: so you've got speech just sitting there and then we dropped into an ancient mammal really simple vocalisation to do a lot of emotional elements of interaction.

00:30:13: And your findings also suggest activity.

00:30:17: the pre-supplementary motor areas predicts how contagious and authentic a laugh is perceived to be.

00:30:27: What do you think a motor region plays such as central role in understanding another person's emotions?

00:30:36: Sorry, I keep telling it was good question but that is really interesting!

00:30:40: We know that the supplementary motor area supplementary, police supplementary and supplementary that does seem to be very involved in initiating laughter.

00:30:52: So studies where people have kind of stimulated there you can get laughter happening.

00:30:57: um... And it we think That one of the things is happening with laughter.

00:31:06: Is that as I say?

00:31:07: It's contagious.

00:31:11: It's a learned behavior, you look at babies they don't show any contagious behaviors.

00:31:14: They don't blink contagiously or yawn contagiously and laugh contagiously.

00:31:19: And these are all things we teach babies to do.

00:31:22: We think that one of the thing is happening with pre-SMA.

00:31:26: Is it part of that priming?

00:31:27: That learnt association You've heard it yourself.

00:31:33: But I mean would be interesting if you saw that with other Contagious behaviours.

00:31:37: so i need more studies there.

00:31:39: but current guess, it's part of that kind of really rapid priming network.

00:31:46: And then and that's why the more activities when people are listening to their laughter they're more contagious... They rate that laughter because you're directly getting an experience with that contagion.

00:31:55: One

00:31:55: of the fascinating aspects of your work is the distinction between spontaneous and volitional laughter.

00:32:08: from an evolutionary perspective What do you think humans have developed these two different forms of laughter?

00:32:18: i think it's because we have two different motor networks.

00:32:22: so everything that we were talking about for the first you know half of the show was about the volitional control as a voice in speaking and singing but whatever else your doing.

00:32:31: And now uses these lateral motor areas on helpfully pointing to my head.

00:32:35: basically you know primary motor cortex primary sensory cortex auditory cortex these are sort of lateral motor and sensory fields, are really important in guiding volitional action.

00:32:48: In contrast, we also have a vocalization network that we share with other mammals which runs from the anterior cingulate down to brainstem nuclei and directly controls their muscles of articulation.

00:33:02: And in other mammals is what drives vocalizations because vocalizations are very reactive and emotional.

00:33:11: they do little volitional control of voice unlike us.

00:33:15: But of course, we do also produce sounds in an involuntary way.

00:33:19: So I was walking down the street once and I slipped on some leaves... ...and thought that it's going to fall over!

00:33:25: And then made a real sound like this.

00:33:27: It is completely involuntry with no use whatsoever but could not stop coming out.

00:33:34: In fact patients who have damage leave them within aphasis syndrome so they've damaged lateral motor areas involved in articulation.

00:33:43: They can still laugh And they can still cry and swear.

00:33:48: Lots of this highly over learnt, very emotional bits of vocalisations are preserved.

00:33:53: So it looks like we have an older pathway which is involved in really involuntary or maybe a highly over learned use the voice but always emotional.

00:34:03: Then you've got more volitional network for everything else.

00:34:05: so I think laughter When you think about last time when were laughing that you could not stop.

00:34:11: That's almost certainly that involuntary network, that midline network because an involuntariesounder start has been triggered and it is just going to happen.

00:34:21: There are no way you can stop this.

00:34:23: In contrast I think a lot of the laughter happens in conversation Because its timed so precisely... ...that looks like the lateral motor system.

00:34:31: And i've published paper with Italian neuroscientist Fausto Caruana where he had this lovely metronalysis looking at brain stimulation.

00:34:41: and when you stimulate in the brain, you get laughter.

00:34:45: And whether or not people feel mirth with a laughter?

00:34:49: You do get a distinction.

00:34:50: so if your going to these more lateral motor areas.

00:34:53: but it's funny where in the kind of more midline older emotional network involuntary networks and the supplementary motor cortex i think that's when you start to see something that people experience is mirthful.

00:35:05: so there's some thing very interesting.

00:35:06: they're missing back.

00:35:08: Maybe key points in the brain like enteriosingulate on the sma where these two networks join up, but this may be something interesting about laughter where maybe we can count bounce back and forth between a voluntary and involuntary laughter.

00:35:22: it definitely to me speaks too different kinds of systems.

00:35:25: Very,

00:35:27: very interesting.

00:35:30: And on your experience which tools more than others helped you to understand all these processes?

00:35:45: Which instruments like TMS, so neuromodulation or functional MRI instruments that more than others helped you to understand this processing?

00:36:05: I think they're complementary.

00:36:08: You learn different things from all of them, so... ...I've learned a lot from doing fMRI because you see the networks and then i've learnt a lot with FNIRs.. ..because you can do much more kind-of naturalistic things.

00:36:17: people aren't lying in the scanner or your'e in the room with them.

00:36:20: And then u get that relationship between SMA activation & peoples ratings Actually happening as a direct measure and then i've learned to lock from.

00:36:32: Work that fast has been doing with you know kind of stimulation studies are really fine fine grain dynamical detail exactly where u r in the brain, and that's telling me what enormous precision.

00:36:43: not just where do get laughter generated but what does it feel like?

00:36:47: so to me I think i'm really complex.

00:36:50: behavior like human use of laughter benefits for having a lot different possible ways of going in, you know.

00:36:56: And I've also done cross-cultural studies with laughter.

00:36:58: that's been really helpful.

00:37:00: and i've done kind of questionnaire.

00:37:02: studies have laughed us looking at people's individual experiences.

00:37:05: so it...I think It really does.

00:37:06: kinda..you need to.

00:37:08: With most human behaviours You benefit from taking more than one More Than One stance and I'd love To try some experience with TMS.

00:37:14: see if we could stop People laughing

00:37:16: Yeah!

00:37:18: And what about recording the voices?

00:37:24: of patients, not only a phasic patient but patients with neurological disorders for instance can help us to understand better the disease itself.

00:37:41: that progression, the prognosis.

00:37:45: What do you think?

00:37:45: Yeah

00:37:47: I think so because again Often the focus is on the linguistic content of what people are saying, but there will be other changes.

00:37:53: So I mean at Parkinson's disease really can affect their voice.

00:37:58: it can effect both the ability to speak and also you know to manage musicality in the voice.

00:38:03: peoples' voices become flat or very quiet um And as i say they're all so.

00:38:09: conditions where the main problem isn't sort of non-verbal elements.

00:38:12: somebody with quotes for an accident syndrome.

00:38:14: They Can Still Speak reasonably fluently, but there's a distortion to the sounds that are causing quite different identity to be expressed.

00:38:23: So I think a better understanding of what is exactly going on... ...is gonna really helpful for both embracing complexity in problems we face and also hopefully helping patients even if it only helps with coming into terms with what has happened.

00:38:40: And you will record them in natural conversation?

00:38:44: in an ecological way.

00:38:48: I mean...

00:38:50: Probably do both because you get really nice recordings if you take somebody into an anarchoic chamber, which not everybody is aware of it's a very natural environment but also If look at people talking together You'll be able to pick up on how much they've changed their voice like the person They're talking too and that would be How much are we going there?

00:39:10: That'd be useful.

00:39:11: index for what kind changes have happened Again, what potential things you could do to support them?

00:39:19: Very nice.

00:39:21: So thank you Professor Scott.

00:39:23: it has been a great pleasure to talk with you today and I enjoy reading all your papers.

00:39:32: You have done a lot of work on the field.

00:39:38: Thank you for joining us And I say bye to all our listeners and you in particular.

00:39:51: Thank you very much, i really enjoyed it!

00:39:55: Bye-bye.

00:39:57: This has been EANcast Weekly Neurology.

00:40:07: thankyou for listening.

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