Arian Shamei, PhD – Speech Scientist
Scientists may be able to ‘listen’ for Alzheimer’s disease, study suggests
November 2024 – The Daily Mail
Link to the original article: https://www.dailymail.co.uk/health/article-14101425/scientists-listen-alzheimers-disease-study.html
Scientists may be able to ‘listen’ for Alzheimer’s disease, study suggests…
Vowel Space reduction in Alzheimer’s Disease: Q&A with Arian Shamei
May 2023 – UBC Language Sciences
Link to the original article: https://languagesciences.ubc.ca/news/may-05-2023/reduction-vowel-space-alzheimers-disease-qa-arian-shamei
Reduced vowel space area (VSA) is a known effect of neurodegenerative diseases such as Parkinson’s disease (PD). In the study, ‘Reduction of Vowel Space in Alzheimer’s Disease‘ by Arian Shamei, Yadong Liu and Dr. Bryan Gick, using large publicly available corpuses, two experiments were conducted comparing the vowel space of speakers with and without Alzheimer’s disease (AD) during spontaneous and read speech. First, a comparison of vowel distance found reduced distance in AD for English spontaneous speech, but not Spanish read speech. Findings were then verified using an unsupervised learning approach to quantify VSA through cluster center detection.
In this Q&A with Language Sciences, Arian Shamei, PhD Candidate in Linguistics at UBC, explains how reduced vowel space area (VSA) is a manifestation of reduced fine motor skills, why natural speech may be more susceptible to VSA reduction than read speech in those Alzheimer’s Disease, and what’s next for this research!
1. Can you explain how reduced vowel space area (VSA) is a manifestation of reduced fine motor skills in neurodegenerative diseases such as Alzheimer’s Disease?
Great question. Believe it or not, speech is movement. In fact, speech movements are some of the most rapid and precise fine motor skills that humans employ. This makes speech a great medium for assessing fine motor skills. People make vowels by moving their tongue into specific positions. The range and precision of these movements is a good reflection of fine motor skills. People with Alzheimer’s Disease (AD) display impairments in fine motor skills throughout the body, so it’s no surprise we can see it in their speech. Specifically, we see that they produce a smaller range of movement when compared to healthy control patients. This reflects observations for other neurodegenerative diseases such as Parkinson’s Disease or ALS where we see fine motor skill deterioration throughout the body mirrored in reduced vowel space.
2. Why might natural speech be more susceptible to VSA reduction than read speech in those with Alzheimer’s Disease?
Natural speech generally involves a faster speech rate and greater variability in all domains compared to read speech. This makes it a tougher motor task than read speech, which typically follows a more monotone cadence at a more consistent speech rate. We see the same pattern for other neurodegenerative diseases too, such as Parkinson’s Disease; reductions to VSA are much greater in natural speech. So the choice of speech task has a big impact on whether changes can be detected in speech. A lot of researchers use read speech because it’s easier to collect and more consistent, and this seems to result in false negatives when looking for changes to speech.
3. How do the vowel systems of English and Spanish differ, and why is it important that these differences are recognized in this research?
In general, the vowel space of English is a lot larger and more varied than Spanish. English also employs prosodic stress on vowels, which changes the duration and articulatory emphasis of a vowel. Spanish vowels on the other hand are fairly consistent. However, regardless of whether a person with AD speaks English or Spanish, they will have the same impairment to fine motor skills, but it’s possible that different languages have different motor demands. There is a lot of research around the world examining how speech is changed by neurodegenerative disease, and the general pattern is that we see changes regardless of the language being spoken because fine motor skills are always affected. Rather, the bigger influence driving variability in findings around the world is the choice of speech task. So it’s important that researchers recognize that looking at read speech may not paint the whole picture.
4. What’s next for this research?
Because speech is a great way to assess fine motor skills, it’s also a fantastic diagnostic tool. There is a lot of research on leveraging speech for the automated detection of neurodegenerative disease. We hope to identify commonalities in changes to speech across languages to improve the efficacy of automated methods for the detection of AD. Artificial intelligence has demonstrated strong potential in distinguishing AD speech from healthy controls, but there is little understanding of what those changes are, when we should expect them, and whether they are specific to individual languages. We have been doing a lot of experiments at the ISRL to get to the bottom of this.
To learn more and read the full study, click here.
Written by Kelsea Franzke
Study prompted by Commander Hadfield comment finds gravity affects astronauts’ speech
Link to the original article: https://research.ubc.ca/study-prompted-commander-hadfield-comment-finds-gravity-affects-astronauts-speech
“Right after I landed, I could feel the weight of my lips and tongue and had to change how I was talking. I didn’t realize I had learned to talk with a weightless tongue.”
Science has studied the effects of lower gravity on the body, but this comment by Commander Chris Hadfield at a press conference prompted University of British Columbia linguists to investigate how space travel might affect astronauts’ speech.
Department of Linguistics professor Bryan Gick and doctoral student Arian Shamei, both Language Sciences members, discuss how vowels produced by astronauts change after a spell in space, and what this tells us about the future of speech in changing gravity.
How did this study come about? What novel results did you find?
BG: Shortly after Chris Hadfield’s landing in 2013, my colleague Carla Hudson Kam mentioned Hadfield’s comments. I have a long-standing interest in the physical mechanisms of speech, so I ran to my computer and wrote up a proposal for a series of studies and a possible grant. It took me several years to find the right circumstances – and the right collaborator – to follow up with a pilot study.
AS: Using NASA audio files from the STS-134 mission in 2011, we measured formant values for five vowels produced by astronaut Mark Kelly before, during, and after the mission. Formant values are correlated to the position of a speaker’s tongue during speech, including height. We found that all vowels were lowered and centralized for post-flight conditions, meaning astronauts speak as if their tongues are effectively heavier upon return from space. Speech sounds requiring upward movements of the tongue were particularly impaired, as these movements are more affected by the force of gravity. This reflects Chris Hadfield’s observations.
Given what we already know about muscle atrophy in low gravity, why is this finding important?
BG: There are many things we don’t understand about the effects of gravity on the body. One of those is on fine motor control – the tiny movements we use for important tasks like speech, facial expression, writing, and so on. We also understand very little in general about adaptation to any kinds of environmental or physical change. This study tells us important information about how our bodies – and specifically how our essential communicative systems – respond to changing circumstances. One thing we do know is that when our production (action) systems are perturbed, this can also change our perceptual (sensory) systems, so this gravitational effect may be affecting not only how we produce speech, but also how we perceive it.
AS: We may know lots about the effects of muscle atrophy in low gravity, but we know very little about how this would affect speech.
Since speech movements are some of the most precise and rapid motor movements undertaken at any time, it gives us a very clear picture of what’s going on in the body following some change to the speaker’s physical and emotional state. Some recent work I published found that the temporal co-ordination of speech movements are severely impaired when someone is intoxicated from cannabis consumption, and that long-term users of cannabis demonstrate these effects even when sober. Speech tells us a lot more about the speaker than what they are actually saying.
What does this mean for humans in space – should astronauts on the ISS be performing tongue exercises?
BG: If gravity changes the way we produce – and potentially perceive – speech, and these effects are most pronounced during mission-critical periods of gravitational change when spoken communication is most essential, then this is certainly something the world’s space agencies should make every effort to understand and mitigate where possible. The next steps would be to outline for the agencies a range of follow-up studies of speech perception and production and other fine motor control under varying gravitational conditions.
This study was published in October in Canadian Acoustics.
Arian Shamei - Research Profile 