Just a few years of early musical training benefits the brain later in life

Older adults who took music lessons as children but haven’t actively played an instrument in decades have a faster brain response to a speech sound than individuals who never played an instrument, according to a study appearing November 6 in the Journal of Neuroscience. The finding suggests early musical training has a lasting, positive effect on how the brain processes sound.

As people grow older, they often experience changes in the brain that compromise hearing. For instance, the brains of older adults show a slower response to fast-changing sounds, which is important for interpreting speech. However, previous studies show such age-related declines are not inevitable: recent studies of musicians suggest lifelong musical training may offset these and other cognitive declines.

In the current study, Nina Kraus, PhD, and others at Northwestern University explored whether limited musical training early in life is associated with changes in the way the brain responds to sound decades later. They found that the more years study participants spent playing instruments as youth, the faster their brains responded to a speech sound.

"This study suggests the importance of music education for children today and for healthy aging decades from now," Kraus said. "The fact that musical training in childhood affected the timing of the response to speech in older adults in our study is especially telling because neural timing is the first to go in the aging adult," she added.

For the study, 44 healthy adults, ages 55-76, listened to a synthesized speech syllable (“da”) while researchers measured electrical activity in the auditory brainstem. This region of the brain processes sound and is a hub for cognitive, sensory, and reward information. The researchers discovered that, despite none of the study participants having played an instrument in nearly 40 years, the participants who completed 4-14 years of music training early in life had the fastest response to the speech sound (on the order of a millisecond faster than those without music training).

"Being a millisecond faster may not seem like much, but the brain is very sensitive to timing and a millisecond compounded over millions of neurons can make a real difference in the lives of older adults," explained Michael Kilgard, PhD, who studies how the brain processes sound at the University of Texas at Dallas and was not involved in this study. "These findings confirm that the investments that we make in our brains early in life continue to pay dividends years later," he added.

(Image: Shutterstock)

Bird study finds key info about human speech-language development

A study led by Xiaoching Li, PhD, at the LSU Health Sciences Center New Orleans Neuroscience Center of Excellence, has shown for the first time how two tiny molecules regulate a gene implicated in speech and language impairments as well as autism disorders, and that social context of vocal behavior governs their function. The findings are published in the October 16, 2013 issue of The Journal of Neuroscience.

Speech and language impairments affect the lives of millions of people, but the underlying neural mechanisms are largely unknown and difficult to study in humans. Zebra finches learn to sing and use songs for social communications. Because the vocal learning process in birds has many similarities with speech and language development in humans, the zebra finch provides a useful model to study the neural mechanisms underlying speech and language in humans.

Mutations in the FOXP2 gene have been linked to speech and language deficits and in autism disorders. A current theory is that a precise amount of FOXP2 is required for the proper development of the neural circuits processing speech and language, so it is important to understand how the FOXP2 gene is regulated. In this study, the research team identified two microRNAs, or miRNAs, – miR-9 and miR-140-5p – that regulate the levels of FOXP2. (MicroRNAs are a new class of small RNA molecules that play an important regulatory role in cell biology. They prevent the production of a particular protein by binding to and destroying the messenger RNA that would have produced the protein.) The researchers showed that in the zebra finch brain, these miRNAs are expressed in a basal ganglia nucleus that is required for vocal learning, and their function is regulated during vocal learning. More intriguingly, the expression of these two miRNAs is also regulated by the social context of song behavior – in males singing undirected songs.

"Because the FOXP2 gene and these two miRNAs are evolutionarily conserved, the insights we obtained from studying birds are highly relevant to speech and language in humans and related neural developmental disorders such as autism," notes Xiaoching Li, PhD,

LSUHSC Assistant Professor of Cell Biology and Anatomy as well as Neuroscience. “Understanding how miRNAs regulate FOXP2 may open many possibilities to influence speech and language development through genetic variations in miRNA genes, as well as behavioral and environmental factors.”

(Image credit)

Turn up the volume? A better way to broadcast over the noise

Traffic, aircraft, mobile devices and personal music equipment are not the only sources of noise pollution. Public address systems have become part of the escalating problem, which according to the World Health Organization, costs Europeans alone the equivalent of 654,000 years of healthy life annually.

But researchers at Stockholm’s KTH Royal Institute of Technology have developed a way to bring down the volume on loud public announcements while preserving their clarity in noisy environments.

“By manipulating speech before it is sent to the loudspeakers, we can enhance the speech signal and adapt it to the surrounding noise,” says Gustav Eje Henter, PhD student at Communication Theory at KTH. “This makes it possible to communicate at much lower volume levels than before.”

Earlier approaches to the problem focused on making the speech more prominent, while the KTH researchers are paying attention to what is actually said. They do this by working with computer and machine speech recognition, which is modeled on human hearing. By creating speech that is easier for computers to recognise, people should benefit as well, the researchers say.

“Our manipulation, which is suited for a computer speech recogniser, also makes it easier for people to hear the right thing,” says Petko Petkov, also a PhD student at Communication Theory. “The modified words sound more distinct from each other, making it easier to distinguish them in the noise.”

Petkov and Henter have developed their method together with Professor Bastiaan Kleijn as part of the European collaborative LISTA– or Listening Talker – project.

A recent global evaluation by the LISTA Consortium at University of Edinburgh showed significant increases in the number of words identified correctly in manipulated speech signals, over unaltered speech. The results of the LISTA evaluation are expected to be published later this year. 

In some cases, the improvement in understanding is equivalent to turning down the speech volume by more than 5 decibels, which is similar to the difference in the strength between car and truck noise, while still being able to hear what is said just as clearly.

“This enables communication in conditions where speech normally would be impossible to understand,” says Henter.

The LISTA project is funded by the European Union’s Future and Emerging Technology framework programme, and involves scientists from Spain, Greece, Sweden and the UK. The techniques developed within the project involve both natural and synthetic speech in different types of noise. In addition to public address systems, the project could benefit a wide range of devices that produce speech output – such as mobile phones, radios and in-car navigation systems.

Decoding ‘noisy’ language in daily life

Suppose you hear someone say, “The man gave the ice cream the child.” Does that sentence seem plausible? Or do you assume it is missing a word? Such as: “The man gave the ice cream to the child.”

A new study by MIT researchers indicates that when we process language, we often make these kinds of mental edits. Moreover, it suggests that we seem to use specific strategies for making sense of confusing information — the “noise” interfering with the signal conveyed in language, as researchers think of it.

“Even at the sentence level of language, there is a potential loss of information over a noisy channel,” says Edward Gibson, a professor in MIT’s Department of Brain and Cognitive Sciences (BCS) and Department of Linguistics and Philosophy.

Gibson and two co-authors detail the strategies at work in a new paper, “Rational integration of noisy evidence and prior semantic expectations in sentence interpretation,” published today in the Proceedings of the National Academy of Sciences.

“As people are perceiving language in everyday life, they’re proofreading, or proof-hearing, what they’re getting,” says Leon Bergen, a PhD student in BCS and a co-author of the study. “What we’re getting is quantitative evidence about how exactly people are doing this proofreading. It’s a well-calibrated process.”

Asymmetrical strategies

The paper is based on a series of experiments the researchers conducted, using the Amazon Mechanical Turk survey system, in which subjects were presented with a series of sentences — some evidently sensible, and others less so — and asked to judge what those sentences meant.

A key finding is that given a sentence with only one apparent problem, people are more likely to think something is amiss than when presented with a sentence where two edits may be needed. In the latter case, people seem to assume instead that the sentence is not more thoroughly flawed, but has an alternate meaning entirely.

“The more deletions and the more insertions you make, the less likely it will be you infer that they meant something else,” Gibson says. When readers have to make one such change to a sentence, as in the ice cream example above, they think the original version was correct about 50 percent of the time. But when people have to make two changes, they think the sentence is correct even more often, about 97 percent of the time.

Thus the sentence, “Onto the cat jumped a table,” which might seem to make no sense, can be made plausible with two changes — one deletion and one insertion — so that it reads, “The cat jumped onto a table.” And yet, almost all the time, people will not infer that those changes are needed, and assume the literal, surreal meaning is the one intended.

This finding interacts with another one from the study, that there is a systematic asymmetry between insertions and deletions on the part of listeners.

“People are much more likely to infer an alternative meaning based on a possible deletion than on a possible insertion,” Gibson says.

Suppose you hear or read a sentence that says, “The businessman benefitted the tax law.” Most people, it seems, will assume that sentence has a word missing from it — “from,” in this case — and fix the sentence so that it now reads, “The businessman benefitted from the tax law.” But people will less often think sentences containing an extra word, such as “The tax law benefitted from the businessman,” are incorrect, implausible as they may seem.

Another strategy people use, the researchers found, is that when presented with an increasing proportion of seemingly nonsensical sentences, they actually infer lower amounts of “noise” in the language. That means people adapt when processing language: If every sentence in a longer sequence seems silly, people are reluctant to think all the statements must be wrong, and hunt for a meaning in those sentences. By contrast, they perceive greater amounts of noise when only the occasional sentence seems obviously wrong, because the mistakes so clearly stand out.

“People seem to be taking into account statistical information about the input that they’re receiving to figure out what kinds of mistakes are most likely in different environments,” Bergen says.

Reverse-engineering the message

Other scholars say the work helps illuminate the strategies people may use when they interpret language.

“I’m excited about the paper,” says Roger Levy, a professor of linguistics at the University of California at San Diego who has done his own studies in the area of noise and language.

According to Levy, the paper posits “an elegant set of principles” explaining how humans edit the language they receive. “People are trying to reverse-engineer what the message is, to make sense of what they’ve heard or read,” Levy says.

“Our sentence-comprehension mechanism is always involved in error correction, and most of the time we don’t even notice it,” he adds. “Otherwise, we wouldn’t be able to operate effectively in the world. We’d get messed up every time anybody makes a mistake.”

Rare primate’s vocal lip-smacks share features of human speech

The vocal lip-smacks that geladas use in friendly encounters have surprising similarities to human speech, according to a study reported in the Cell Press journal Current Biology on April 8th. The geladas, which live only in the remote mountains of Ethiopia, are the only nonhuman primate known to communicate with such a speech-like, undulating rhythm. Calls of other monkeys and apes are typically one or two syllables and lack those rapid fluctuations in pitch and volume.

This new evidence lends support to the idea that lip-smacking, a behavior that many primates show during amiable interactions, could have been an evolutionary step toward human speech.

"Our finding provides support for the lip-smacking origins of speech because it shows that this evolutionary pathway is at least plausible," said Thore Bergman of the University of Michigan in Ann Arbor. "It demonstrates that nonhuman primates can vocalize while lip-smacking to produce speech-like sounds."

Bergman first began to wonder about the geladas’ sounds when he began his fieldwork in 2006. “I would find myself frequently looking over my shoulder to see who was talking to me, but it was just the geladas,” he recalled. “It was unnerving to have primate vocalizations sound so much like human voices.”

That was something that he had never experienced in the company of other primates. Then Bergman came across a paper in Current Biology last year proposing vocalization while lip-smacking as a possible first step to human speech, and something clicked.

Bergman has now analyzed recordings of the geladas’ vocalizations, known as “wobbles,” to find a rhythm that closely matches human speech. In other words, because they vocalize while lip-smacking, the pattern of sound produced is structurally similar to human speech.

In both lip-smacking and speech, the rhythm corresponds to the opening and closing of parts of the mouth. What’s more, Bergman said, lip-smacking might serve the same purpose as language in many basic human interactions—think of how friends bond through small talk.

"Language is not just a great tool for exchanging information; it has a social function," Bergman said. "Many verbal exchanges appear to serve a function similar to lip-smacking."

The great orchestral work of speech

What goes on inside our heads is similar to an orchestra. For Peter Hagoort, Director at the Max Planck Institute for Psycholinguistics, this image is a very apt one for explaining how speech arises in the human brain. “There are different orchestra members and different instruments, all playing in time with each other, and sounding perfect together.”

When we speak, we transform our thoughts into a linear sequence of sounds. When we understand language, exactly the opposite occurs: we deduce an interpretation from the speech sounds we hear. Closely connected regions of the brain – like the Broca’s area and Wernicke’s area – are involved in both processes, and these form the neurobiological basis of our capacity for language.

The 58-year-old scientist, who has had a strong interest in language and literature since his youth, has been searching for the neurobiological foundations of our communication since the 1990s. Using imaging processes, he observes the brain “in action” and tries to find out how this complex organ controls the way we speak and understand speech.

Making language visible

Hagoort is one of the first researchers to combine psychological theories with neuroscientific methods in his efforts to understand this complex interaction. Because this is not possible without the very latest technology, in 1999, Hagoort established the Nijmegen-based Donders Centre for Cognitive Neuroimaging where an interdisciplinary team of researchers uses state-of-the-art technology, for example MRI and PET scanners, to find out how the brain succeeds in combining functions like memory, speech, observation, attention, feelings and consciousness.

The Dutch scientist is particularly fascinated by the temporal sequence of speech. He discovered, for example, that the brain begins by collecting grammatical information about a word before it compiles information about its sound. This first reliable real-time measurement of speech production in the brain provided researchers with a basis for observing speakers in the act of speaking. They were then able to obtain new insights about why the complex orchestral work of language is impaired, for example, after strokes and in the case of disorders like dyslexia and autism.

“Language is an essential component of human culture, which distinguishes us from other species,” says Hagoort. “Young children understand language before they even start to speak. They master complex grammatical structures before they can add 3 and 13. Our brain is tuned for language at a very early stage,” stresses Hagoort, referring to research findings. The exact composition of the orchestra in our heads and the nature of the score on which the process of speech is based are topics which Hagoort continues to research.

Children With Brain Lesions Able To Use Gestures Important To Language Learning

Children with brain lesions suffered before or around the time of birth are able to use gestures – an important aspect of the language learning process– to convey simple sentences, a Georgia State University researcher has found.

Şeyda Özçalışkan, assistant professor of psychology, and fellow researchers at the University of Chicago, looked at children who suffered lesions to one side of the brain to see whether they used gestures similar to typically developing children. She examined gestures such as pointing to a cookie while saying “eat” to convey the meaning “eat cookie,” several months before expressing such sentences exclusively in speech.

“We do know that children with brain injuries show an amazing amount of plasticity (the ability to change) for language learning if they acquire lesions early in life,” Özçalışkan said. “However, we did not know whether this plasticity was characterized by the same developmental trajectory shown for typically developing children, with gesture leading the way into speech.  We looked at the onset of different sentence constructions in children with early brain injuries, and wanted to find out if we could see precursors of different sentence types in gesture.

“For children with brain injuries, we found that this pattern holds, similar to typically developing children,” she said. “Children with unilateral brain injuries produce different kinds of simple sentences several months later than typically developing children. More important, the delays we observe in producing different sentences in speech are preceded by a similar delay in producing the same sentences in gesture-speech combinations.”

Children with brain injuries also had a more difficult time in producing complex sentences across gesture and speech, such as conveying relationships between actions, for example saying “help me do it” while making a painting gesture.

“This in turn was later reflected in a much narrower range of complex sentence types expressed in their speech,” Özçalışkan said. “This suggested to us, in general, that producing sentences across gesture and speech may serve as an embodied sensorimotor experience, that might help children take the next developmental step in producing these sentences in speech.

“And if you bypass the gesture-speech combination stage, that might negatively affect developing a broader representation of complex sentence types in speech.”

The researchers also compared children with smaller brain lesions against children with large lesions, and found more of a delay in producing sentences, both in speech and in gesture-speech combinations, in children with large lesions.

The research has implications for developing interventions to help children with the language learning process, “as it shows that gestures are integral to the process of language learning even when that learning is taking place in an injured brain,” Özçalışkan said.

“When children do different kinds of sentence combinations across gesture and speech, that’s like a signal to the caregiver that ‘I’m ready for this,’” she said. “The caregiver can then provide relevant input to the child, and that could in turn help the child take the next developmental step in producing that sentence entirely in speech.”