Showing posts with label Speech. Show all posts
Showing posts with label Speech. Show all posts

Aug 20, 2023

Brain recordings capture musicality of speech -- with help from Pink Floyd

As the chords of Pink Floyd's "Another Brick in the Wall, Part 1," filled the surgery suite, neuroscientists at Albany Medical Center diligently recorded the activity of electrodes placed on the brains of patients undergoing epilepsy surgery.

The goal? To capture the electrical activity of brain regions tuned to attributes of the music -- tone, rhythm, harmony and words -- to see if they could reconstruct what the patient was hearing.

More than a decade later, after detailed analysis of data from 29 such patients by neuroscientists at the University of California, Berkeley, the answer is clearly yes.

The phrase "All in all it was just a brick in the wall" comes through recognizably in the reconstructed song, its rhythms intact, and the words muddy, but decipherable. This is the first time researchers have reconstructed a recognizable song from brain recordings.

The reconstruction shows the feasibility of recording and translating brain waves to capture the musical elements of speech, as well as the syllables. In humans, these musical elements, called prosody -- rhythm, stress, accent and intonation -- carry meaning that the words alone do not convey.

Because these intracranial electroencephalography (iEEG) recordings can be made only from the surface of the brain -- as close as you can get to the auditory centers -- no one will be eavesdropping on the songs in your head anytime soon.

But for people who have trouble communicating, whether because of stroke or paralysis, such recordings from electrodes on the brain surface could help reproduce the musicality of speech that's missing from today's robot-like reconstructions.

"It's a wonderful result," said Robert Knight, a neurologist and UC Berkeley professor of psychology in the Helen Wills Neuroscience Institute who conducted the study with postdoctoral fellow Ludovic Bellier. "One of the things for me about music is it has prosody and emotional content. As this whole field of brain machine interfaces progresses, this gives you a way to add musicality to future brain implants for people who need it, someone who's got ALS or some other disabling neurological or developmental disorder compromising speech output. It gives you an ability to decode not only the linguistic content, but some of the prosodic content of speech, some of the affect. I think that's what we've really begun to crack the code on."

As brain recording techniques improve, it may be possible someday to make such recordings without opening the brain, perhaps using sensitive electrodes attached to the scalp. Currently, scalp EEG can measure brain activity to detect an individual letter from a stream of letters, but the approach takes at least 20 seconds to identify a single letter, making communication effortful and difficult, Knight said.

"Noninvasive techniques are just not accurate enough today. Let's hope, for patients, that in the future we could, from just electrodes placed outside on the skull, read activity from deeper regions of the brain with a good signal quality. But we are far from there," Bellier said.

Bellier, Knight and their colleagues reported the results today in the journal PLOS Biology, noting that they have added "another brick in the wall of our understanding of music processing in the human brain."

Reading your mind? Not yet.

The brain machine interfaces used today to help people communicate when they're unable to speak can decode words, but the sentences produced have a robotic quality akin to how the late Stephen Hawking sounded when he used a speech-generating device.

"Right now, the technology is more like a keyboard for the mind," Bellier said. "You can't read your thoughts from a keyboard. You need to push the buttons. And it makes kind of a robotic voice; for sure there's less of what I call expressive freedom."

Bellier should know. He has played music since childhood -- drums, classical guitar, piano and bass, at one point performing in a heavy metal band. When Knight asked him to work on the musicality of speech, Bellier said, "You bet I was excited when I got the proposal."

In 2012, Knight, postdoctoral fellow Brian Pasley and their colleagues were the first to reconstruct the words a person was hearing from recordings of brain activity alone.

More recently, other researchers have taken Knight's work much further. Eddie Chang, a UC San Francisco neurosurgeon and senior co-author of the 2012 paper, has recorded signals from the motor area of the brain associated with jaw, lip and tongue movements to reconstruct the speech intended by a paralyzed patient, with the words displayed on a computer screen.

That work, reported in 2021, employed artificial intelligence to interpret the brain recordings from a patient trying to vocalize a sentence based on a set of 50 words.

While Chang's technique is proving successful, the new study suggests that recording from the auditory regions of the brain, where all aspects of sound are processed, can capture other aspects of speech that are important in human communication.

"Decoding from the auditory cortices, which are closer to the acoustics of the sounds, as opposed to the motor cortex, which is closer to the movements that are done to generate the acoustics of speech, is super promising," Bellier added. "It will give a little color to what's decoded."

For the new study, Bellier reanalyzed brain recordings obtained in 2012 and 2013 as patients were played an approximately 3-minute segment of the Pink Floyd song, which is from the 1979 album The Wall. He hoped to go beyond previous studies, which had tested whether decoding models could identify different musical pieces and genres, to actually reconstruct music phrases through regression-based decoding models.

Bellier emphasized that the study, which used artificial intelligence to decode brain activity and then encode a reproduction, did not merely create a black box to synthesize speech. He and his colleagues were also able to pinpoint new areas of the brain involved in detecting rhythm, such as a thrumming guitar, and discovered that some portions of the auditory cortex -- in the superior temporal gyrus, located just behind and above the ear -- respond at the onset of a voice or a synthesizer, while other areas respond to sustained vocals.

The researchers also confirmed that the right side of the brain is more attuned to music than the left side.

"Language is more left brain. Music is more distributed, with a bias toward right," Knight said.

"It wasn't clear it would be the same with musical stimuli," Bellier said. "So here we confirm that that's not just a speech-specific thing, but that's it's more fundamental to the auditory system and the way it processes both speech and music."

Knight is embarking on new research to understand the brain circuits that allow some people with aphasia due to stroke or brain damage to communicate by singing when they cannot otherwise find the words to express themselves.

Read more at Science Daily

Aug 4, 2023

Humans unable to detect over a quarter of deepfake speech samples

The study, published today in PLOS ONE, is the first to assess human ability to detect artificially generated speech in a language other than English.

Deepfakes are synthetic media intended to resemble a real person's voice or appearance. They fall under the category of generative artificial intelligence (AI), a type of machine learning (ML) that trains an algorithm to learn the patterns and characteristics of a dataset, such as video or audio of a real person, so that it can reproduce original sound or imagery.

While early deepfake speech algorithms may have required thousands of samples of a person's voice to be able to generate original audio, the latest pre-trained algorithms can recreate a person's voice using just a three-second clip of them speaking. Open-source algorithms are freely available and while some expertise would be beneficial, it would be feasible for an individual to train them within a few days.

Tech firm Apple recently announced software for iPhone and iPad that allows a user to create a copy of their voice using 15 minutes of recordings.

Researchers at UCL used a text-to-speech (TTS) algorithm trained on two publicly available datasets, one in English and one in Mandarin, to generate 50 deepfake speech samples in each language. These samples were different from the ones used to train the algorithm to avoid the possibility of it reproducing the original input.

These artificially generated samples and genuine samples were played for 529 participants to see whether they could detect the real thing from fake speech. Participants were only able to identify fake speech 73% of the time, which improved only slightly after they received training to recognise aspects of deepfake speech.

Kimberly Mai (UCL Computer Science), first author of the study, said: "Our findings confirm that humans are unable to reliably detect deepfake speech, whether or not they have received training to help them spot artificial content. It's also worth noting that the samples that we used in this study were created with algorithms that are relatively old, which raises the question whether humans would be less able to detect deepfake speech created using the most sophisticated technology available now and in the future."

The next step for the researchers is to develop better automated speech detectors as part of ongoing efforts to create detection capabilities to counter the threat of artificially generated audio and imagery.

Though there are benefits from generative AI audio technology, such as greater accessibility for those whose speech may be limited or who may lose their voice due to illness, there are growing fears that such technology could be used by criminals and nation states to cause significant harm to individuals and societies.

Documented cases of deepfake speech being used by criminals include one 2019 incident where the CEO of a British energy company was convinced to transfer hundreds of thousands of pounds to a false supplier by a deepfake recording of his boss's voice.

Read more at Science Daily

May 25, 2022

Horses and pigs sense harsh speaking tones

How we speak matters to animals. Horses, pigs and wild horses can distinguish between negative and positive sounds from their fellow species and near relatives, as well as from human speech. This, according to new research in behavioral biology at the University of Copenhagen. The study provides insight into the history of emotional development and opens up interesting perspectives with regards to animal welfare.

The idea of horse whisperers -- those with a talent for communicating with horses -- may bring a chuckle to many. But according to new research from the University of Copenhagen and ETH Zurich, there may be something about their whispering skills. In an international collaboration, along with researchers Anne-Laure Maigrot and Edna Hillmann, behavioral biologist Elodie Briefer of the University of Copenhagen's Department of Biology investigated whether a range of animals can distinguish between positively and negatively charged sounds.

"The results showed that domesticated pigs and horses, as well as Asian wild horses, can tell the difference, both when the sounds come from their own species and near relatives, as well as from human voices," explains Elodie Briefer. Pigs were studied along with boar, their wild relatives. Just as in the case of the two related horse species, the pigs clearly reacted to how the sounds of their counterparts were emotionally charged. In fact, to the same extent as when it came to sounds of their own kind.

The animals even showed the ability to distinguish between positively or negatively charged human voices. While their reactions were more subdued, all but wild boars reacted differently when exposed to human speech that was either charged with positive or negative emotion.

Human gibberish

The researchers played recordings of animal sounds and human voices from hidden speakers.

To avoid having the domesticated animals react to specific words, positive and negative human speech was performed by a professional voice actor in a kind of gibberish without any meaningful phrases.

The animals' behavioral reactions were recorded in a number of categories used in previous studies -- everything from their ear position to their movement or lack thereof.

On this basis, the researchers concluded that: How we speak matters to animals.

"Our results show that these animals are affected by the emotions we charge our voices with when we speak to or are around them. They react more strongly -- generally faster -- when they are met with a negatively charged voice, compared to having a positively charged voice played to them first. In certain situations, they even seem to mirror the emotion to which they are exposed" says Elodie Briefer.

Do animals have an emotional life?

Part of the aim of the study, was to investigate the possibility of "emotional contagion" in animals -- a kind of mirroring of emotion. Situations where one expressed emotion is assumed by another. In behavioral biology, this type of reaction is seen as the first step in the empathy category.

"Should future research projects clearly demonstrate that these animals mirror emotions, as this study suggests, it will be very interesting in relation to the history of the development of emotions and the extent to which animals have an emotional life and level of consciousness," says Elodie Briefer.

The study was unable to detect clear observations of "emotional contagion," but an interesting result was in the order by which the sounds where delivered. Sequences in which the negative sound was played first triggered stronger reactions in all but the wild boars. This included human speech.

According to Elodie Briefer, this suggests that the way we talk around animals and the way we talk to animals may have an impact on their well-being.

"It means that our voices have a direct impact on the emotional state of animals, which is very interesting from an animal welfare perspective," she says.

This knowledge doesn't just raise ethical questions about how we perceive animals -- and vice versa, it can also be used as a concrete means of improving animals' daily lives, if those who work with them are familiar with it.

"When the animals reacted strongly to hearing negatively charged speech first, the same is also true in the reverse. That is, if animals are initially spoken to in a more positive, friendly voice, when met by people, they should react less. They may become calmer and more relaxed," explains Elodie Briefer.

Next step for the Copenhagen University researcher is the switchover. She and her colleagues, are now looking into how well we humans are able to understand animal sounds of emotion.

How the researchers did it
 

  • The animals in the experiment were either privately owned (horses), from a research station (pigs) or living in zoos in Switzerland and France (wild Przewalski's horses and wild boars).
  • The researchers used animal sounds with a previously established emotion valence.
  • The animal sounds and human voices were played to the animals from hidden speakers.
  • Doing so required high sound quality to ensure for the natural frequencies heard best by animals.
  • The sounds were played in sequences with either a positive or negatively charged sound first, then a pause, -- and then sounds with reverse valence, i.e. the reverse emotion.
  • The reactions were recorded on video, which the researchers could subsequently use to observe and record the animals' reactions.
  • Three theses can explain the animal reactions


The researchers worked with three theories about which conditions they expected to influence the animals' reactions in the experiment:

Phylogeny
 

  • According to this theory, depending on the evolution of species, i.e., the history of evolution, animals with a common ancestry may be able to perceive and interpret each other's sounds by virtue of their common biology.


Domestication
 

  • Close contact with humans, over a long period of time, may have increased the ability to interpret human emotions.
  • Animals that are good at picking up human emotions might have been preferred for breeding.


Familiarity
 

  • Based on learning. The specific animals in the study may have learned a greater understanding of humans and fellow species, who they were in close contact with where they were housed.


The conclusion is as follows. Among the horse species, the phylogeny thesis best explained their behavior. In contrast, the behavior of the pig species best fit the domestication hypothesis.

Read more at Science Daily

May 7, 2022

Neuroscientists find multiple brain regions control speech, challenging common assumption

Neurobiologists at the University of Pittsburgh School of Medicine give new meaning to the term "motor mouth" in a study published today in the Proceedings of the National Academy of Sciences. By carefully mapping neural networks in marmoset and macaque monkeys, they determined that multiple areas in the brain's frontal lobe control the muscles of vocalization and could provide a foundation for complex speech.

The findings -- which could lead to a better understanding of speech disorders -- refute a long-existing presumption that only the primary motor cortex, nicknamed M1, directly influences the larynx or voice box, said principal investigator Peter L. Strick, Ph.D., Thomas Detre Professor and chair of neurobiology at Pitt. Instead, several cortical regions send signals to laryngeal muscles to create greater vocal finesse in some nonhuman primates.

"This kind of parallel processing in our neural wiring might explain why humans are capable of highly sophisticated language that allows us to share information, express and perceive emotion, and tell memorable stories," said Strick, who also is scientific director of Pitt's Brain Institute. "Our remarkable speech skills are due to more evolved brains, not better muscles."

Led by Christina M. Cerkevich, Ph.D., research assistant professor of neurobiology, the investigators compared in marmosets and macaques neural networks that are the origin of descending command signals to control monkey vocalizations.

"We selected these two monkey species because of the striking differences in their vocal behavior," Cerkevich explained. "Marmosets readily vocalize in ways that are akin to humans by taking turns to speak and altering the volume, timing and pitch of their calls to each other. Macaques, on the other hand, make mostly simple, spontaneous calls."

The researchers injected a transneuronal tracer made from rabies virus into the cricothyroid muscle of the monkeys' larynxes. The tracer infects nerve cells and has the unique property of moving from one neuron to another only at synapses, which are the special sites where neurons interact with each other. This makes it possible to track neuronal circuits from the muscle back to the areas of the cerebral cortex that control it.

In addition to M1, both kinds of monkeys had multiple premotor areas in the frontal lobe that send descending command signals to the cricothyroid muscle. But two of the premotor areas provided a substantially larger source of descending output in marmosets, leading the researchers to propose that the enhanced vocal motor skills of marmosets are due, in part, to the expansion of neural signaling from these premotor areas.

"This result challenges the long-held view that improvements in motor skills of vocalization are due largely to changes in the output from M1, the primary motor cortex," Strick said. "It appears there is no single control center, but rather parallel processing sites that enable complex vocalization and, ultimately, speech."

Read more at Science Daily

Dec 10, 2021

Speaking 'baby talk' to infants isn’t just cute: It could help them learn to make words

A new study suggests that when parents baby talk to their infants, they might be helping them learn to produce speech.

The way we instinctively speak to babies -- higher pitch, slower speed, exaggerated pronunciation -- not only appeals to them, but likely helps them learn to understand what we're saying. New research from the University of Florida suggests that baby talk can have another, previously unknown benefit: helping babies learn to produce their own speech. By mimicking the sound of a smaller vocal tract, the researchers think, we're cluing babies in to how the words should sound coming out of their own mouths.

"It seems to stimulate motor production of speech, not just the perception of speech," said Matthew Masapollo, Ph.D., an assistant professor in UF's Department of Speech, Language, and Hearing Sciences and director of the UF Laboratory for the Study of Cognition, Action, and Perception of Speech in the College of Public Health and Health Professions. "It's not just goo-goo ga-ga."

In the study, the researchers changed the frequency sounds to mimic either an infant or adult vocal tract, and then tested how infants reacted. Six- to eight-month-old babies "displayed a robust and distinct preference for speech with resonances specifying a vocal tract that is similar in size and length to their own," they wrote.

Four- to six-month old babies didn't have that preference, suggesting that older babies' dawning ability to control their voices and make words out of babble could be what makes the infant-like sounds more appealing.

Though baby talk may sound simple, it's accomplishing a lot, says coauthor Linda Polka, Ph.D., of McGill University.

"We're trying to engage with the infant to show them something about speech production," she said. "We're priming them to process their own voice."

Read more at Science Daily

Aug 3, 2021

Learning foreign languages can affect the processing of music in the brain

Research has shown that a music-related hobby boosts language skills and affects the processing of speech in the brain. According to a new study, the reverse also happens -- learning foreign languages can affect the processing of music in the brain.

Research Director Mari Tervaniemi from the University of Helsinki's Faculty of Educational Sciences investigated, in cooperation with researchers from the Beijing Normal University (BNU) and the University of Turku, the link in the brain between language acquisition and music processing in Chinese elementary school pupils aged 8-11 by monitoring, for one school year, children who attended a music training programme and a similar programme for the English language. Brain responses associated with auditory processing were measured in the children before and after the programmes. Tervaniemi compared the results to those of children who attended other training programmes.

"The results demonstrated that both the music and the language programme had an impact on the neural processing of auditory signals," Tervaniemi says.

Learning achievements extend from language acquisition to music

Surprisingly, attendance in the English training programme enhanced the processing of musically relevant sounds, particularly in terms of pitch processing.

"A possible explanation for the finding is the language background of the children, as understanding Chinese, which is a tonal language, is largely based on the perception of pitch, which potentially equipped the study subjects with the ability to utilise precisely that trait when learning new things. That's why attending the language training programme facilitated the early neural auditory processes more than the musical training."

Tervaniemi says that the results support the notion that musical and linguistic brain functions are closely linked in the developing brain. Both music and language acquisition modulate auditory perception. However, whether they produce similar or different results in the developing brain of school-age children has not been systematically investigated in prior studies.

At the beginning of the training programmes, the number of children studied using electroencephalogram (EEG) recordings was 120, of whom more than 80 also took part in EEG recordings a year later, after the programme.

In the music training, the children had the opportunity to sing a lot: they were taught to sing from both hand signs and sheet music. The language training programme emphasised the combination of spoken and written English, that is, simultaneous learning. At the same time, the English language employs an orthography that is different from Chinese. The one-hour programme sessions were held twice a week after school on school premises throughout the school year, with roughly 20 children and two teachers attending at a time.

Read more at Science Daily

Jul 16, 2021

Bats are kings of small talk in the air

Bat conversations might be light on substance, according to researchers from the University of Cincinnati.

Echoes from bats are so simple that a sound file of their calls can be compressed 90% without losing much information, according to a study published in the journal PLOS Computational Biology.

The study demonstrates how bats have evolved to rely on redundancy in their navigational "language" to help them stay oriented in their complex three-dimensional world.

"If you can make decisions with little information, everything becomes simpler. That's nice because you don't need a lot of complex neural machinery to process and store that information," study co-author Dieter Vanderelst said.

UC researchers suspected that the calls of bats contain redundant information and that bats might use efficient encoding strategies to extract the most relevant information from their echoes. Many natural stimuli encountered by animals have a lot of redundancy. Efficient neural encoding retains essential information while reducing this redundancy.

To test their hypothesis, they built their own "bat on a stick," a tripod-mounted device that emits a pulse of sound sweeping from 30 to 70 kilohertz, a frequency range used by many bats. By comparison, human speech typically ranges from 125 to 300 hertz (or 0.125 to 0.3 kHz).

More than 1,000 echoes were captured in distinct indoor and outdoor environments such as in a barn, in different-sized rooms, among bushes and tree branches and in a garden.

Researchers converted the recorded echoes to a graph of the sound, called a cochleogram. Then they subjected these graphs to 25 filters -- essentially compressing the data. They trained a neural network, a computer system modeled on the human brain, to determine if the filtered graphs still contained enough information to complete a number of sonar-based tasks known to be performed by bats.

They found that the neural network correctly identified the location of the echoes even when the cochleogram was stripped of as much as 90% of its data.

"What that tells us is you can compress that data and still do what you need to do. It also means if you're a bat, you can do this efficiently," said Vanderelst, an assistant professor in UC's College of Arts and Sciences and in the College of Engineering and Applied Science.

Vanderelst said researchers often can infer what bats are doing just by listening to their calls.

"Even if you don't see the bat, you can tell with a high degree of certainty what a bat is doing," he said. "If it calls more frequently, it's looking for something. If the calls are spread out, it's cruising or studying something far away."

Bats produce their ultrasonic calls with a larynx much like ours. But what a voice box. It can contract 200 times a second, making it the fastest known muscle in all mammals.

The nighttime forest can be deafening to people because of its chorus of frogs and drone of insects. But Vanderelst said the ultrasonic frequency by comparison is pretty quiet, allowing bats to hear their own chittering calls that bounce off tree branches and other obstacles during echolocation.

While bats use different chirps for navigating than for communicating with each other, Vanderelst said they're all pretty simple. But human language has lots of built-in redundancy as well, Vanderelst said.

Fr xmpl, cn y rd ths sntnc wth mssng vwls?

"Take out a lot of letters in a sentence and it's still readable," Vanderelst said.

UC graduate Adarsh Chitradurga Achutha, Vanderelst's student, was the study's lead author. Co-authors include Vanderelst's mentor Herbert Peremans at the University of Antwerp, Belgium, and bat expert Uwe Firzlaff with the University of Munich, Germany.

The way bats perceive the world is fascinating both from biological and engineering perspectives, Vanderelst said.

Read more at Science Daily

Jul 15, 2021

'Neuroprosthesis' restores words to man with paralysis

Researchers at UC San Francisco have successfully developed a "speech neuroprosthesis" that has enabled a man with severe paralysis to communicate in sentences, translating signals from his brain to the vocal tract directly into words that appear as text on a screen.

The achievement, which was developed in collaboration with the first participant of a clinical research trial, builds on more than a decade of effort by UCSF neurosurgeon Edward Chang, MD, to develop a technology that allows people with paralysis to communicate even if they are unable to speak on their own. The study appears July 15 in the New England Journal of Medicine.

"To our knowledge, this is the first successful demonstration of direct decoding of full words from the brain activity of someone who is paralyzed and cannot speak," said Chang, the Joan and Sanford Weill Chair of Neurological Surgery at UCSF, Jeanne Robertson Distinguished Professor, and senior author on the study. "It shows strong promise to restore communication by tapping into the brain's natural speech machinery."

Each year, thousands of people lose the ability to speak due to stroke, accident, or disease. With further development, the approach described in this study could one day enable these people to fully communicate.

Translating Brain Signals into Speech

Previously, work in the field of communication neuroprosthetics has focused on restoring communication through spelling-based approaches to type out letters one-by-one in text. Chang's study differs from these efforts in a critical way: his team is translating signals intended to control muscles of the vocal system for speaking words, rather than signals to move the arm or hand to enable typing. Chang said this approach taps into the natural and fluid aspects of speech and promises more rapid and organic communication.

"With speech, we normally communicate information at a very high rate, up to 150 or 200 words per minute," he said, noting that spelling-based approaches using typing, writing, and controlling a cursor are considerably slower and more laborious. "Going straight to words, as we're doing here, has great advantages because it's closer to how we normally speak."

Over the past decade, Chang's progress toward this goal was facilitated by patients at the UCSF Epilepsy Center who were undergoing neurosurgery to pinpoint the origins of their seizures using electrode arrays placed on the surface of their brains. These patients, all of whom had normal speech, volunteered to have their brain recordings analyzed for speech-related activity. Early success with these patient volunteers paved the way for the current trial in people with paralysis.

Previously, Chang and colleagues in the UCSF Weill Institute for Neurosciences mapped the cortical activity patterns associated with vocal tract movements that produce each consonant and vowel. To translate those findings into speech recognition of full words, David Moses, PhD, a postdoctoral engineer in the Chang lab and one of the lead authors of the new study, developed new methods for real-time decoding of those patterns and statistical language models to improve accuracy.

But their success in decoding speech in participants who were able to speak didn't guarantee that the technology would work in a person whose vocal tract is paralyzed. "Our models needed to learn the mapping between complex brain activity patterns and intended speech," said Moses. "That poses a major challenge when the participant can't speak."

In addition, the team didn't know whether brain signals controlling the vocal tract would still be intact for people who haven't been able to move their vocal muscles for many years. "The best way to find out whether this could work was to try it," said Moses.

The First 50 Words

To investigate the potential of this technology in patients with paralysis, Chang partnered with colleague Karunesh Ganguly, MD, PhD, an associate professor of neurology, to launch a study known as "BRAVO" (Brain-Computer Interface Restoration of Arm and Voice). The first participant in the trial is a man in his late 30s who suffered a devastating brainstem stroke more than 15 years ago that severely damaged the connection between his brain and his vocal tract and limbs. Since his injury, he has had extremely limited head, neck, and limb movements, and communicates by using a pointer attached to a baseball cap to poke letters on a screen.

The participant, who asked to be referred to as BRAVO1, worked with the researchers to create a 50-word vocabulary that Chang's team could recognize from brain activity using advanced computer algorithms. The vocabulary -- which includes words such as "water," "family," and "good" -- was sufficient to create hundreds of sentences expressing concepts applicable to BRAVO1's daily life.

For the study, Chang surgically implanted a high-density electrode array over BRAVO1's speech motor cortex. After the participant's full recovery, his team recorded 22 hours of neural activity in this brain region over 48 sessions and several months. In each session, BRAVO1 attempted to say each of the 50 vocabulary words many times while the electrodes recorded brain signals from his speech cortex.

Translating Attempted Speech into Text

To translate the patterns of recorded neural activity into specific intended words, the other two lead authors of the study, Sean Metzger, MS and Jessie Liu, BS, both bioengineering doctoral students in the Chang Lab used custom neural network models, which are forms of artificial intelligence. When the participant attempted to speak, these networks distinguished subtle patterns in brain activity to detect speech attempts and identify which words he was trying to say.

To test their approach, the team first presented BRAVO1 with short sentences constructed from the 50 vocabulary words and asked him to try saying them several times. As he made his attempts, the words were decoded from his brain activity, one by one, on a screen.

Then the team switched to prompting him with questions such as "How are you today?" and "Would you like some water?" As before, BRAVO1's attempted speech appeared on the screen. "I am very good," and "No, I am not thirsty."

The team found that the system was able to decode words from brain activity at rate of up to 18 words per minute with up to 93 percent accuracy (75 percent median). Contributing to the success was a language model Moses applied that implemented an "auto-correct" function, similar to what is used by consumer texting and speech recognition software.

Moses characterized the early trial results as a proof of principle. "We were thrilled to see the accurate decoding of a variety of meaningful sentences," he said. "We've shown that it is actually possible to facilitate communication in this way and that it has potential for use in conversational settings."

Looking forward, Chang and Moses said they will expand the trial to include more participants affected by severe paralysis and communication deficits. The team is currently working to increase the number of words in the available vocabulary, as well as improve the rate of speech.

Both said that while the study focused on a single participant and a limited vocabulary, those limitations don't diminish the accomplishment. "This is an important technological milestone for a person who cannot communicate naturally," said Moses, "and it demonstrates the potential for this approach to give a voice to people with severe paralysis and speech loss."

Read more at Science Daily

Jun 24, 2021

Children's beat gestures predict the subsequent development of their oral skills

A study published on 21 May in Child Development shows that the early production of beat gestures with the hands (i.e., gestures normally associated with emphasis that do not represent the semantic content of speech) by infants between 14 and 58 months of age in natural interactions with their carers predicts that in their later development, nearing the age of five, these children obtain better results insofar as their oral narrative skills.

The authors analysed the predictive value of beat gestures, compared with flip gestures of the hands and iconic gestures

However, the study did not find these same effects when children produced other types of gestures, such as iconic gestures (gestures that visually represent the semantic content of discourse, such as moving the hands in the shape of a ball to express "ball") and hand flip gestures (gestures made by twisting the wrist, for example to express "don't know" with uncertainty while raising the shoulders).

The study is the result of collaboration between the UPF Prosodic Studies (GrEP) group and the Department of Translation and Language Sciences and the Goldin-Meadow Lab at the University of Chicago (Illinois, USA), research carried out by Ingrid Vilà-Giménez (UPF and UdG) and Pilar Prieto (ICREA, UPF) with the researchers Natalie Dowling and Susan Goldin-Meadow (University of Chicago, USA) and Ö. Ece Demir-Lira (University of Iowa).

A longitudinal database on language development was used

Through a longitudinal methodology, the study analysed data at different points in the children's development. The data belong to a large longitudinal database on language development belonging to the University of Chicago. The researchers analysed speech and the production of three types of gesture of 45 children aged between 14 and 58 months while interacting with their carers at mealtime or during games sessions or other activities such as reading books. Specifically, they examined the predictive value of beat gestures, compared with flip gestures of the hands and iconic gestures. At 5 years of age, the same children participated in a narrative task in which they had to tell a story from a cartoon without sound.

The study has shown that beat gestures produced by children aged 14 to 58 months play a very important role in narrative development at later stages

The results showed that beat gestures produced by children aged 14 to 58 months play a very important role in narrative development at later stages because they can predict improvements in children's oral skills some years later. Although the results of the study do not provide empirical evidence as to whether such beat gesture simply reflects that the child has the ability to structure speech or multimodally mark elements of speech associated with prominence of speech (i.e., to mark emphasis), the researchers argue that this kind of gesture plays a very important pragmatic role in children's early speech.

It should be noted that these pragmatic functions of beat gestures are related with the function of structuring narrative discourse. Therefore, as the study results would suggest, the authors highlight that it can be stated that the pragmatic functions of beat gestures in children's early narrative speeches may be highly important for the development of their initial speech as well as for developing their oral narrative skills at a later age.

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Jun 4, 2021

Age doesn't affect perception of 'speech-to-song illusion'

A strange thing sometimes happens when we listen to a spoken phrase again and again: It begins to sound like a song.

This phenomenon, called the "speech-to-song illusion," can offer a window into how the mind operates and give insight into conditions that affect people's ability to communicate, like aphasia and aging people's decreased ability to recall words.

Now, researchers from the University of Kansas have published a study in PLOS ONE examining if the speech-to-song illusion happens in adults who are 55 or older as powerfully as it does with younger people.

The KU team recruited 199 participants electronically on Amazon's Mechanical Turk (MTurk), a website used to conduct research in the field of psychology. The subjects listened to a sound file that exemplified the speech-to-song illusion, then completed surveys relating to three different studies.

"In the first study, we just played them the canonical stimulus made by the researcher that discovered this illusion -- if that can't create the illusion, then nothing can," said co-author Michael Vitevitch, professor of psychology at KU. "Then we simply asked people, 'Did you experience the illusion or not?' There was no difference in the age of the number of people that said yes or no."

While the researchers hypothesized fewer older people would perceive the illusion than younger people, the study showed no difference due to age.

While older and younger people perceived the speech-to-song illusion at the same rates, in the second study investigators sought to discover if older people experienced it less powerfully.

"We thought maybe 'yes or no' was too coarse of a measurement, so let's try to use a five-point rating scale," Vitevitch said. "Maybe older adults would rate it as being a little bit more speech-like and younger adults will rate it as being more song-like and you'll see it on this five-point scale, maybe. But there was no difference in the numbers with the younger and older adults."

In the third study, Vitevitch wanted to see if older adults perhaps experience the illusion more slowly than younger people.

"We thought maybe it's not the strength of the illusion that's different but maybe it's when the illusion occurred," he said. "So, we did a final study and asked people to click a button on the screen when their perception shifted from speech to song -- we thought maybe older adults would need a few more repetitions for it to switch over. But we got the same number for both younger adults and older."

Vitevitch's co-authors were KU undergraduate researchers Hollie Mullin, Evan Norkey and Anisha Kodwani, as well as Nichol Castro of the University of Buffalo.

According to Vitevitch, the findings might translate to good news for older adults.

"We have this common misconception that everything goes downhill cognitively as we age," said the KU researcher. "That's not the case. There are some things that do get worse with age, but there are some things that actually get better with age, and some things that stay consistent with age -- in the case of this illusion, you're going to get equally suckered whether you're an older adult or a younger adult."

In another aspect of the research, the investigators found people with musical training experienced the speech-to-song illusion at similar rates as people with no background in music.

"There's a debate about whether musicians or musically trained people experienced the illusion more or less or sooner or more strongly," Vitevitch said. "We looked at it and there was really no difference there either. Musicians and non-musically trained people experience this at about the same rates and have the same sort of experience. The amount of musical training didn't matter. It was just amazingly consistent however we looked at it."

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Apr 26, 2021

Can a newborn's brain discriminate speech sounds?

People's ability to perceive speech sounds has been deeply studied, specially during someone's first year of life, but what happens during the first hours after birth? Are babies born with innate abilities to perceive speech sounds, or do neural encoding processes need to age for some time?

Researchers from the Institute of Neurosciences of the University of Barcelona (UBNeuro) and the Sant Joan de Déu Research Institute (IRSJD) have created a new methodology to try to answer this basic question on human development.

The results, published in the Nature's open-access journal Scientific Reports, confirm that newborn neural encoding of voice pitch is comparable to the adults' sabilities after three years of being exposed to language. However, there are differences regarding the perception of spectral and temporal fine structures of sounds, which consists on the ability to distinguish between vocal sounds such as /o/ and /a/. Therefore, according to the authors, neural encoding of this sound aspect, recorded for the first time in this study, is not found mature enough after being born, but it needs a certain exposure to the language as well as stimulation and time to develop.

According to the researchers, knowing the level of development typical in these neural encoding processes from birth will enable them to make an "early detection of language impairments, which would provide an early intervention or stimulus to reduce future negative consequences."

The study is led by Carles Escera, professor of Cognitive Neuroscience at the Department of Clinical Psychology and Psychobiology of the UB, and has been carried out at the IRSJD, in collaboration with Maria Dolores Gómez Roig, head of the Department of Obstetrics and Gynecology of Hospital Sant Joan de Déu. The study is also signed by the experts Sonia Arenillas Alcón, first author of the article, Jordi Costa Faidella and Teresa Ribas Prats, all members of the Cognitive Neuroscience Research Group (Brainlab) of the UB.

Decoding the spectral and temporal fine structure of sound

In order to distinguish the neural response to speech stimuli in newborns, one of the main challenges was to record, using the baby's electroencephalogram, a specific brain response: the frequency-following response (FFR). The FFR provides information on the neural encoding of two specific features of sound: fundamental frequency, responsible for the perception of voice pitch (high or low), and the spectral and temporal fine structure. The precise encoding of both features is, according to the study, "fundamental for the proper perception of speech, a requirement in future language acquisition."

To date, the available tools to study this neural encoding enabled researchers to determine whether the newborn's baby was able to encode inflections in the voice pitch, but it did not when it came to the spectral and temporal fine structure. "Inflections in voice pitch contour are very important, especially in tonal variations like in Mandarin, as well as to perceive the prosody from speech that transmits emotional content of what is said. However, the spectral and temporal fine structure of sound is the most relevant aspect in language acquisition regarding non-tonal languages like ours, and the few existing studies on the issue do not inform about the precision with which a newborn's brain encodes it," note the authors.

The main cause of this lack of studies is the technical limitation caused by the type of sounds used to conduct these tests. Therefore, authors have developed a new stimulus (/oa/) whose internal structure (increasing change in voice pitch, two different vocals) allows them to evaluate the precision of the neural encoding of both features of the sound simultaneously using the FFR analysis.

An adapted test to the limitations of the hospital environment

One of the most highlighted aspects of the study is that the stimulus and the methodology are compatible to the typical limitations of the hospital environment in which the tests are carried out. "Time is essential in the FFR research with newborns. On the one hand, because recording time limitations determine the stimuli they can record. On the other hand, for the actual conditions of the situation of newborns in hospitals, where there is a frequent and continuous access to the baby and the mother so they receive the required care and undergo evaluations and routine tests to rule out health problems," authors add. Considering these restrictions, the responses of the 34 newborns that were part of the study were recorded in sessions that lasted between twenty and thirty minutes, almost half the time used in common sessions in studies on speech sound discrimination.

A potential biomarker of learning problems

After this study, the objective of the researchers is to characterize the development f neural encoding of the spectral and temporal fine structure of speech sounds over time. To do so, they are currently recording the frequency-following response in those babies that took part in the present study, who are now 21 months old. "Given that the two first years of life are a critical period of stimulation for language acquisition, this longitudinal evaluation of the development will enable us to have a global view on how these encoding skills mature over the first months of life," note the researchers.

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Apr 16, 2021

Brain regions responsible for intoxicating effects of alcohol

The slurred speech, poor coordination, and sedative effects of drinking too much alcohol may actually be caused by the breakdown of alcohol products produced in the brain, not in the liver as scientists currently think. That is the finding of a new study led by researchers from the University of Maryland School of Medicine (UMSOM) and the National Institute on Alcohol Abuse and Alcoholism. It was published recently in the journal Nature Metabolism and provides new insights into how alcohol may affect the brain and the potential for new treatments to treat alcohol misuse.

It is well known that the liver is the major organ that metabolizes alcohol, using the enzyme alcohol dehydrogenase to convert alcohol into a compound called acetaldehyde. Acetaldehyde, which has toxic effects, is quickly broken down into a more benign substance called acetate. This occurs through a different enzyme called acetaldehyde dehydrogenase 2 (ALDH2). Until now, alcohol and acetaldehyde, produced by the liver, have been considered important players in triggering the cognitive impairment associated with imbibing. Acetate, on the other hand, was considered relatively unimportant in producing effects like motor impairment, confusion, and slurred speech. Researchers also did not know which brain region or particular brain cells were most important for alcohol metabolism.

To learn more about the role played by the brain in alcohol metabolism, the researchers measured the distribution of ALDH2 enzyme in the cerebellum, using magnetic resonance (MR) scanners in both mice and in human tissue. They observed that ALDH2 was expressed in the cerebellum, in a type of nerve cell called an astrocyte, in both human brain tissue and in living mice.

The researchers found that this enzyme controlled the conversion of acetaldehyde into acetate in the brain. They also found alcohol-induced cellular and behavioral effects in specific regions of the brain where this enzyme was expressed. Acetate was found to interact with the brain messenger chemical called GABA, which is known to decrease activity in the nervous system. This decreased activity can lead to drowsiness, impair coordination, and lower normal feelings of inhibition.

"We found ALDH2 was expressed in cells known as astrocytes in the cerebellum, a brain region that controls balance and motor coordination," said Qi Cao, PhD, Assistant Professor of Diagnostic Radiology and Nuclear Medicine at the University of Maryland School of Medicine. "We also found that when ALDH2 was removed from these cells, the mice were resistant to motor impairment inducted by alcohol consumption."

Su Xu, PhDHe and his team also found the enzyme ALDH2 in other brain regions responsible for emotional regulation and decision-making (both impaired by excess alcohol consumption), including in the hippocampus, amydala, and prefrontal cortex.

These findings suggest that certain brain regions are important for alcohol metabolism and that abnormalities in the enzyme production in these brain regions can lead to detrimental effects associated with alcohol misuse. They also suggest that acetate produced in the brain and in the liver differ in their ability to affect motor and cognitive function.

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Apr 8, 2021

The truth about doublespeak: Is it lying or just being persuasive?

Doublespeak, or the use of euphemisms to sway opinion, lets leaders avoid the reputational costs of lying while still bringing people around to their way of thinking, a new study has found.

Researchers at the University of Waterloo found that the use of agreeable euphemistic terms biases people's evaluations of actions to be more favourable. For example, replacing a disagreeable term, "torture," with something more innocuous and semantically agreeable, like "enhanced interrogation."

"Like the much-studied phenomenon of 'fake news,' manipulative language can serve as a tool for misleading the public, doing so not with falsehoods but rather with the strategic use of euphemistic language," said Alexander Walker, lead author of the study and a PhD candidate in cognitive psychology at Waterloo. "The avoidance of objectively false claims may provide the strategic user of language with plausible deniability of dishonesty, thus protecting them from the reputational cost associated with lying."

As part of a series of studies investigating the effectiveness, consequences and mechanisms of doublespeak in a psychological context, the researchers investigated whether the use of language characteristic of doublespeak can be used to influence peoples' evaluations of actions.

The researchers identified doublespeak as the strategic manipulation of language to influence the opinions of others by representing the truth in a manner that benefits one's self. To do this, the researchers assessed whether substituting an agreeable term -- for example, "working at a meat-processing plant" in place of a semantically related disagreeable term like "working at a slaughterhouse" -- has an impact on how a person's actions are interpreted.

The researchers' results confirmed that peoples' evaluations of an action can be biased in a predictable, self-serving way when an individual employs the strategic use of more or less agreeable terms when describing an action.

"Our study shows how language can be used strategically to shape peoples' opinions of events or actions," Walker said. "With a lower level of risk, individuals may be able to utilize linguistic manipulation, such as doublespeak, often without correction."

From Science Daily

Mar 1, 2021

Neanderthals had the capacity to perceive and produce human speech

 Neandertals -- the closest ancestor to modern humans -- possessed the ability to perceive and produce human speech, according to a new study published by an international multidisciplinary team of researchers including Binghamton University anthropology professor Rolf Quam and graduate student Alex Velez.

"This is one of the most important studies I have been involved in during my career," says Quam. "The results are solid and clearly show the Neandertals had the capacity to perceive and produce human speech. This is one of the very few current, ongoing research lines relying on fossil evidence to study the evolution of language, a notoriously tricky subject in anthropology."

The evolution of language, and the linguistic capacities in Neandertals in particular, is a long-standing question in human evolution.

"For decades, one of the central questions in human evolutionary studies has been whether the human form of communication, spoken language, was also present in any other species of human ancestor, especially the Neandertals," says coauthor Juan Luis Arsuaga, Professor of Paleontology at the Universidad Complutense de Madrid and co-director of the excavations and research at the Atapuerca sites. The latest study has reconstructed how Neandertals heard to draw some inferences about how they may have communicated.

The study relied on high resolution CT scans to create virtual 3D models of the ear structures in Homo sapiens and Neandertals as well as earlier fossils from the site of Atapuerca that represent ancestors of the Neandertals. Data collected on the 3D models were entered into a software-based model, developed in the field of auditory bioengineering, to estimate the hearing abilities up to 5 kHz, which encompasses most of the frequency range of modern human speech sounds. Compared with the Atapuerca fossils, the Neandertals showed slightly better hearing between 4-5 kHz, resembling modern humans more closely.

In addition, the researchers were able to calculate the frequency range of maximum sensitivity, technically known as the occupied bandwidth, in each species. The occupied bandwidth is related to the communication system, such that a wider bandwidth allows for a larger number of easily distinguishable acoustic signals to be used in the oral communication of a species. This, in turn, improves the efficiency of communication, the ability to deliver a clear message in the shortest amount of time. The Neandertals show a wider bandwidth compared with their ancestors from Atapuerca, more closely resembling modern humans in this feature.

"This really is the key," says Mercedes Conde-Valverde, professor at the Universidad de Alcalá in Spain and lead author of the study. "The presence of similar hearing abilities, particularly the bandwidth, demonstrates that the Neandertals possessed a communication system that was as complex and efficient as modern human speech."

"One of the other interesting results from the study was the suggestion that Neandertal speech likely included an increased use of consonants," said Quam. "Most previous studies of Neandertal speech capacities focused on their ability to produce the main vowels in English spoken language. However, we feel this emphasis is misplaced, since the use of consonants is a way to include more information in the vocal signal and it also separates human speech and language from the communication patterns in nearly all other primates. The fact that our study picked up on this is a really interesting aspect of the research and is a novel suggestion regarding the linguistic capacities in our fossil ancestors."

Thus, Neandertals had a similar capacity to us to produce the sounds of human speech, and their ear was "tuned" to perceive these frequencies. This change in the auditory capacities in Neandertals, compared with their ancestors from Atapuerca, parallels archaeological evidence for increasingly complex behavioral patterns, including changes in stone tool technology, domestication of fire and possible symbolic practices. Thus, the study provides strong evidence in favor of the coevolution of increasingly complex behaviors and increasing efficiency in vocal communication throughout the course of human evolution.

The team behind the new study has been developing this research line for nearly two decades, and has ongoing collaborations to extend the analyses to additional fossil species. For the moment, however, the new results are exciting.

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Jun 10, 2020

How the brain controls our speech

Speaking requires both sides of the brain. Each hemisphere takes over a part of the complex task of forming sounds, modulating the voice and monitoring what has been said. However, the distribution of tasks is different than has been thought up to now, as an interdisciplinary team of neuroscientists and phoneticians at Goethe University Frankfurt and the Leibniz-Centre General Linguistics Berlin has discovered: it is not just the right hemisphere that analyses how we speak -- the left hemisphere also plays a role.

Until now, it has been assumed that the spoken word arises in left side of the brain and is analysed by the right side. According to accepted doctrine, this means that when we learn to speak English and for example practice the sound equivalent to "th," the left side of the brain controls the motor function of the articulators like the tongue, while the right side analyses whether the produced sound actually sounds as we intended.

The division of labour actually follows different principles, as Dr Christian Kell from the Department of Neurology at Goethe University explains: "While the left side of the brain controls temporal aspects such as the transition between speech sounds, the right hemisphere is responsible for the control of the sound spectrum. When you say 'mother', for example, the left hemisphere primarily controls the dynamic transitions between "th" and the vowels, while the right hemisphere primarily controls the sounds themselves." His team, together with the phonetician Dr Susanne Fuchs, was able to demonstrate this division of labour in temporal and spectral control of speech for the first time in studies in which speakers were required to talk while their brain activities were recorded using functional magnetic resonance imaging.

A possible explanation for this division of labour between the two sides of the brain is that the left hemisphere generally analyses fast processes such as the transition between speech sounds better than the right hemisphere. The right hemisphere could be better at controlling the slower processes required for analysing the sound spectrum. A previous study on hand motor function that was published in the scientific publication "elife" demonstrates that this is in fact the case. Kell and his team wanted to learn why the right hand was preferentially used for the control of fast actions and the left hand preferred for slow actions. For example, when cutting bread, the right hand is used to slice with the knife while the left hand holds the bread.

In the experiment, scientists had right-handed test persons tap with both hands to the rhythm of a metronome. In one version they were supposed to tap with each beat, and in another only with every fourth beat. As it turned out, the right hand was more precise during the quick tapping sequence and the left hemisphere, which controls the right side of the body, exhibited increased activity. Conversely, tapping with the left hand corresponded better with the slower rhythm and resulted in the right hemisphere exhibiting increased activity.

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Jan 12, 2020

Speech-disrupting brain disease reflects patients' native tongue

English and Italian speakers with dementia-related language impairment experience distinct kinds of speech and reading difficulties based on features of their native languages, according to new research by scientists at the UC San Francisco Memory and Aging Center and colleagues at the Neuroimaging Research Unit and Neurology Unit at the San Raffaele Scientific Institute in Milan.

Neurologists had long assumed that brain diseases that impact language abilities would manifest in essentially the same way in patients around the world. But recent discoveries have begun to question that assumption. For instance, Italian speakers with dyslexia tend to have less severe reading impairment than English or French speakers due to Italian's simpler and more phonetic spelling.

"Clinical criteria for diagnosing disorders that affect behavior and language are still mainly based on studies of English speakers and Western cultures, which could lead to misdiagnosis if people who speak different languages or come from another cultural background express symptoms differently," said study senior author Maria Luisa Gorno-Tempini, MD, PhD, a professor of neurology and psychiatry and the Charles Schwab Distinguished Professor in Dyslexia and Neurodevelopment at the UCSF Memory and Aging Center. "It is critical going forward that studies take language and cultural differences into account when studying brain disorders that affect higher cognitive functions -- which we know are greatly impacted by culture, environment, and experience."

The new study, published January 10, 2020 in Neurology, the medical journal of the American Academy of Neurology, focused on patients with primary progressive aphasia (PPA), a neurodegenerative disorder that affects language areas in the brain, a condition often associated with Alzheimer's disease, frontotemporal lobar degeneration, and other dementia disorders.

The researchers recruited 20 English-speaking PPA patients from the UCSF Memory and Aging Center and 18 Italian-speaking PPA patients from San Raffaele Hospital, all of whom shared a variant of PPA characterized by difficulty producing or pronouncing words -- so-called non-fluent PPA.

"We wanted to study patients with PPA to understand whether people from different language backgrounds actually experienced the disease differently, and what that might mean for how we try to help patients remain resilient to the disease," said study lead author Elisa Canu, PhD, a neuropsychologist and researcher in the San Raffaele Scientific Institute's Neuroimaging Research Unit, which is led by co-author Massimo Filippi, MD, full professor of neurology at the affiliated Vita-Salute San Raffaele University, and director of the neurology and neurophysiology units at the San Raffaele Hospital.

Cognitive tests and MRI brain scans revealed similar cognitive function and comparable levels of brain degeneration in the two groups. But when the researchers compared their performance on a battery of linguistic tests, they observed a key difference.

English speakers had more trouble pronouncing words -- the traditional hallmark of nonfluent PPA -- and tended to speak less than usual. In contrast, Italian speakers with the same disorder had fewer pronunciation difficulties but tended to produce much shorter and grammatically simpler sentences. For example, when asked to describe a drawing of a family at a lake house picnicking and flying a kite, Italian speakers with non-fluent PPA might respond (in Italian): "The man and the woman and the dog"; "Boat in the water"; "Family have picnic"; "There is a kite."

"We think this is specifically because the consonant clusters that are so common in English pose a challenge for a degenerating speech-planning system," said Gorno-Tempini, who directs the language neurobiology laboratory at the UCSF Memory and Aging Center, and is co-director of the UCSF Dyslexia Center and the recently launched UCSF-UC Berkeley Schwab Dyslexia and Cognitive Diversity Center. "In contrast, Italian is easier to pronounce, but has much more complex grammar, and this is how Italian speakers with PPA tend to run into trouble."

The results are important for efforts to ensure accurate diagnoses for patients with PPA across different cultures: in the current study the Italian speakers do not match the established diagnostic criteria for nonfluent PPA as closely as the English speakers, since the criteria are based on studies of English-speaking patients.

"This means that there are probably many people around the world -- including non-native English speakers in the U.S. -- who are not getting the right diagnosis because their symptoms don't match what is described in clinical manuals based on studies of native English speakers," said Gorno-Tempini.

The researchers acknowledge that this is a small study and cannot completely exclude the possibility that differences in dementia severity, undetected anatomical differences and differences in education level between Italian and English participants could be confounding factors in the results.

Future studies in partnership with the Global Brain Health Institute (GBHI), a joint effort of UCSF and Trinity College Dublin to reduce the impact of dementia around the world, will attempt to replicate the findings in larger groups of patients, and look for further differences between speakers of even more diverse, non-Western languages, such as Chinese and Arabic.

Read more at Science Daily

Jun 26, 2019

Scientists closer to unraveling mechanisms of speech processing in the brain

In the 1860s, French physician Paul Broca published his findings that the brain's speech production center was located in the left hemisphere. Though scientists have largely accepted since then that the left half of the brain dominates language processing, the reasons behind this lateralization have remained unclear.

"The lateralization of language processing in the auditory cortical areas of the brain has been known for over 150 years, but the function, neural mechanisms, and development of this hemispheric specialization are still unknown," said Hysell V. Oviedo, a biology professor with The Graduate Center, CUNY and the City College of New York.

A new study from Oviedo's lab, published in Nature Communications, makes headway into this mystery. Using the mouse as a model system, the researchers observed different specializations between the left and right auditory processing centers of the brain, and found differences in their wiring diagrams that may explain their distinct speech processing functions.

In addition to answering long-standing questions in neuroscience and language processing, the results of Oviedo's study could someday lead to a better understanding of certain mental health problems. Autism spectrum disorder has been linked to a failure of lateralized language processing to develop between the two halves of the brain. And abnormal lateralization is a risk factor for auditory hallucinations in schizophrenia.

One common feature of mouse vocalizations is syllables with downward jumps in pitch. The left auditory cortex in the mouse showed greater activation in response to these tone sequences, whereas the right auditory cortex appeared to be more of a generalist, responding to any tone sequence. Specializations to detect specific tone sequences prevalent in vocalizations could underlie the left auditory center's dominance in processing the content or meaning of speech. While the right auditory center's generalist scheme could underlie its dominance in processing the intonation or prosody of speech.

Notably, the specialized differences between the left and right sides are not innate. Rather, Oviedo says, the differences between their circuitry depend on the acoustic environment in which the mouse was raised.

"Our discovery of the differences in the wiring diagram provides the opportunity to study the molecular phenotypes that shape the development of vocalization processing and how it goes awry in neurodevelopmental communication disorders," Oviedo said.

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