Undergrad Science - Speech, Stuttering and Rhythm | Jeremy Taigman

How’s it going everyone? My name is Jeremy. I’m a student at the University of Michigan studying neuroscience And I’m here to talk with you all about a lot of really cool scientific concepts including the brain, Speech, music, and rhythm before we get into all of that though I’m gonna introduce a bit about my own personal research. I’m a member of the speech Neurophysiology lab at the University of Michigan and what our group investigates is developmental stuttering in adults and children What exactly is stuttering though We all may have the common idea that stuttering is the repetition of certain Syllables or words in a sentence of speech and this is for the most part, correct We use the more formal definition in our lab though. That stuttering is a neurodevelopmental disorder characterized by involuntary disruptions to again a rhythmic flow of speech There’s often a false conception that stuttering is rooted more in nervousness or anxiety And while these can exacerbate the symptoms of stuttering It is again a more rooted in the brain and that someone who stutters lacks the ability to produce the various tongue and mouth motor movements necessary for fluent speech Why is speech research so important though, well, look at what we’re doing right now we’re communicating thoughts and ideas So fluently and cohesively that we often take it for granted Speech is the primary method of communication for humans and for someone who isn’t able to speak fluently They aren’t as effectively able to state their internal thoughts and emotions and principles Fluent speech is something every individual should be entitled to have and this is why stuttering research has so much utility since increasing the efficacy of speech therapies for individuals who stutter will hopefully, down the line, allow a widespread increase in fluency in speech in stuttering populations Now we define stuttering as a neurodevelopmental Disorder but apart from solely the brain there are so many other factors necessary To understanding stuttering one of which is actually rhythm and how we perceive rhythms around us. I I know what you may be thinking what do rhythm and stuttering really have to do with each other? They seem like independent concepts one involves more hearing and one has to do more with speech But to put this in the perspective It’s well understood in the field of stuttering research now that for when an individual who stutters has an external Pacing signal played for them, like a metronome, that puts out consistent beats in a manner like I’m doing by snapping my finger The individual that stutters is able to train their actual speech output to that rhythm that they’re hearing and show immediate fluency increases in the short term Now there’s a lot going on in these images but let’s pay attention to the one on the right for a second This is basically a functional MRI Image scan of a brain of someone who is currently completing a rhythm Discrimination task the methods of which we’ll talk about a bit more later What’s important from these images is that there’s a lot of overlap between two distinct areas of the brain the basal ganglia and the supplementary motor area which are important for our motor movements and Also the thalamus which is important for our sensory perceptions and how we perceive sound and speech for instance This is direct evidence that how we talk and how we perceive rhythm are Processes that show a lot of overlap in the brain and also in real life consider the fact that some people who stutter show Disfluencies in normal conversational speech but when these same people are asked to sing They show no disfluencies at all.

Since singing is an activity using speech that also involves rhythm and beat 04:15 - with all these ideas We had the hypothesis that adults who stutter may perceive rhythms less effectively and accurately Than an individual that has normal fluent speech and to test this idea. We incorporated a rhythm Discrimination test which is going to be the activity I’m going to talk about next and that you’ll be able to complete at home through an online example I provided In our experiment, both adults who stutter and adults with fluent speech completed this rhythm discrimination task, which is outlined below Across many trials each subject heard a standard rhythm played twice and these two plays were identical to each other the subject then heard a third comparison rhythm a Decision time was then allotted where the subject had to decide By pressing certain keys on a computer keypad Whether they thought the standard and comparison rhythms were the same or different from each other How accurate one was in discriminating the rhythms from each other meant they had a higher overall score for the task so accuracy would be thinking that the standard and comparison rhythm were the same when they actually were the same and Correctly indicating that they were different when they really were different so important to the study are what we like to call Covariance and in this case performance on this task may be influenced by one’s overall musical training history how much they’ve listened to music in the past or have been trained in a musical instrument in the past for instance and Also their working memory ability which in our study we measured by having each subject conduct a separate working memory assessment Now, I’m gonna give the exact same rhythm discrimination task that all the subjects in this study Completed to my sister, mother, and father and I’m gonna look at their results in accuracy and in the act of constantly hypothesizing, I think that my sister is gonna perform a bit better just because she has a more extensive musical training history and Often utilizes working memory a lot more since she’s currently a student just like myself We’ll see what the results are and we’ll check back in a little bit Here’s some footage of my sister completing the rhythm discrimination test across each trial she’s hearing the different rhythms over the earphone as audio and She’s hitting one on the keyboard if she thinks the rhythms are the same and two if she thinks the standard and comparison rhythm are different When she’s all set I’m going to give the same test to my mom and dad and then I’m gonna score each of their tests and compare them Alright guys I just compared the scores from my sister and my parents and it turns out and I was actually right My sister did perform slightly better on the test and was more accurately able to discriminate the rhythms that she heard over audio now again We need to consider that myself my sister and my parents are all fluent monolingual speakers of English we don’t struggle with any of the Disfluencies in speech that an adult who stutters does and our performance on this test May differ drastically from an adult of similar age and experience as any of the four of us that does stutter Because remember a lot of studies have suggested That adults who stutter rely more on a deficient internal timing mechanism and have less effective integration of audio and motor Functionality than those with fluent speech now the results from the actual study that was conducted at the speech Neurophysiology lab were pretty interesting while stuttering adults performed slightly worse on the rhythm Discrimination task than adult controls the difference was not statistically significant. This is really interesting actually since another study performed in 2013 that used a basically identical rhythm discrimination test showed that between children who stutter and children with fluid speech there actually is a significant difference in performance on this test What’s the “So what?” of this data though? Remember that across all humans. There is a lot of interaction in the basal ganglia thalamocortical axis as we called it what we can tell though is that since there was a difference between children who stutter and Fluent children in the task and not really that much of a difference in adults who stutter and fluently speaking adults in the rhythm discrimination test the extent to which there is overlap in this axis of our brain and the extent to which there is integration of speech and rhythm systems may differ with age This means that when it comes to treating stuttering with rhythm- based speech therapy in children and adults Again, really the specific rhythm elements may have more utility in certain age groups more than others Another conclusion we were able to draw from our data is that for both adults who stutter and adults with fluent speech a larger extent of musical training history and also higher working memory capacity was correlated with better scores on the rhythm discrimination test Now here’s where you all have a chance to get a taste of the test completed in this study unfortunately due to permissions the numerous amounts of files and programs required and how difficult it is to actually Score the test and get a performance score itself I’m not able to deliver the exact test for you all to complete at home however attached in the description to this video is a link to the website for the music and neuroscience lab at Western University in London Ontario under the leadership of Dr. Jessica Graham Under the rhythm discrimination heading there are two trials where just like the adults who stutter and control adults in our study You’ll be asked to hear two rhythms and you’ll then have to think about if they are the same or different from each other Trial one is simple and trial two is more complex and maybe a bit harder Try it out with your friends and family and also think about who may perform better Thank you all so much for watching I hope you leave today with a better understanding of how speech and rhythm are connected and I hope you also leave with the better understanding of one of the main tenets of scientific research that ideas that may seem Independent from each other initially really can be connected in great ways and have large amounts of clinical utility .