Hearing: Brain mechanisms makes the auditory system sensitive to behaviourally relevant sounds

How do we hear? More specifically, how does the auditory center of the brain discern important sounds – such as communication from members of the same species – from relatively irrelevant background noise?

The answer depends on the regulation of sound by specific neurons in the auditory cortex of the brain, but the precise mechanisms of those neurons have remained unclear.

Now, a new study from the Perelman School of Medicine at the University of Pennsylvania has isolated how neurons in the rat's primary auditory cortex (A1) preferentially respond to natural vocalizations from other rats over intentionally modified vocalisations (background sounds).

A computational model developed by the study authors, which successfully predicted neuronal responses to other new sounds, explained the basis for this preference.

The research is published in the Journal of Neurophysiology. Rats communicate with each other mostly through ultrasonic vocalisations (USVs) beyond the range of human hearing.

Maria N. Geffen

Although the existence of these USV conversations has been known for decades, "the acoustic richness of them has only been discovered in the last few years," said senior study author Maria N. Geffen, PhD, assistant professor of Otorhinolaryngology: Head and Neck Surgery at Penn.

That acoustical complexity raises questions as to how the animal brain recognizes and responds to the USVs.

"We set out to characterize the responses of neurons to USVs and to come up with a model that would explain the mechanism that makes these neurons preferentially responsive to these relevant sounds."

Geffen and her colleagues obtained recordings of USVs from two rats kept together in a cage, then played the recordings to a separate group of male rats, while their neuronal responses were acquired and recorded.

The researchers also used USV recordings that were modified in several ways, such as having background sounds filtered out and being played backwards and at different speeds to mimic unimportant background noise.

"We found that neurons in the auditory cortex respond strongly and selectively to the original ultrasonic vocalisations and not the transformed versions we created," says Geffen. "

"Using the data collected on the responses of A1 neurons to various USVs, the researchers developed a computational model that could predict the activity of an individual neuron based on the pitch and duration of the USV. "

"Geffen observes that "the details of their responses could be predicted with high accuracy." It was possible to determine which aspects of the acoustic input best drove individual neurons.

Remarkably, it turned out that the acoustic parameters that worked best in driving the neuronal responses corresponded to the statistics of the natural vocalizations rats produce.

The work makes clear for the first time, says Geffen, "the mechanisms of how the auditory system picks out behaviorally relevant sounds, such as same species communication signals, and processes them more effectively than less relevant sounds.

This information is fundamental in understanding how sound perception helps animals survive. We conclude that neurons in the auditory cortex are specialized for processing and efficiently responding to natural and behaviourally relevant sounds."

Dyslexia: Phonics Alphabet A-Z Sounds for Children - Video

This video from helpingtogrow.com teaches the actual phonic sounds of the alphabet from A to Z.

The Role of Phonology 
In the world of dyslexia, it is necessary to return again and again to the very basics of phonics and “sounding out” words – even in adulthood, since reading fluency is often a lifelong problem.

The place to start is to learn the alphabet, not by the names of the letters, but by the sounds they make. Songs and videos with a phonetic alphabet like the one above are widely available.

The next step is to practice saying and memorize the most common words in the English language.

About 50% of all written material is made up of the 100 most frequent words, so reading fluency depends on learning words such as “the,” “no,” “on,” “like” and “open.”

For longer words, a student must learn to break down words into semantic or syntactic chunks. For example, an ending of “-s” or “-es” signifies a plural noun or a third person singular verb.

A prefix of “un-” indicates some type of negative meaning. If a person can learn to read and understand part of a word, then the rest of the word can be dissected, too.

Latin is sometimes recommended to high school students with dyslexia, because every word in a Latin sentence must be broken down into prefix, stem, infix and suffix to unlock the meaning.

Babies Absorb Sounds and Languages Traits in the Womb

Babies only hours old are able to differentiate between sounds from their native language and a foreign language, scientists have discovered.

The study indicates that babies begin absorbing language while still in the womb, earlier than previously thought.

Sensory and brain mechanisms for hearing are developed at 30 weeks of gestational age, and the new study shows that unborn babies are listening to their mothers talk during the last 10 weeks of pregnancy and at birth can demonstrate what they've heard.

"The mother has first dibs on influencing the child's brain," said Patricia Kuhl, co-author and co-director of the Institute for Learning and Brain Sciences at the University of Washington.

"The vowel sounds in the mother's speech are the loudest units and the fetus locks onto them."

Previously, researchers had shown that newborns are born ready to learn and begin to discriminate between language sounds within the first months of life, but there was no evidence that language learning had occurred in utero.

"This is the first study that shows fetuses learn prenatally about the particular speech sounds of a mother's language," said Christine Moon, lead author and a professor of psychology at Pacific Lutheran University in Tacoma, Wash.

"This study moves the measurable result of experience with speech sounds from six months of age to before birth."

The results will be published in an upcoming issue of the journal Acta Paediatrica. Forty infants, about 30 hours old and an even mix of girls and boys, were studied in Tacoma and Stockholm, Sweden.

While still in the nursery, the babies listened to vowel sounds in their native tongue and in foreign languages.

Their interest in the sounds was captured by how long they sucked on a pacifier that was wired into a computer measuring the babies' reaction to the sounds.

Longer or shorter sucking for unfamiliar or familiar sounds is evidence for learning, because it indicates that infants can differentiate between the sounds heard in utero.

In both countries, the babies at birth sucked longer for the foreign language than they did for their native tongue.

The researchers say that infants are the best learners, and discovering how they soak up information could give insights on lifelong learning.

"We want to know what magic they put to work in early childhood that adults cannot," Kuhl said. "We can't waste that early curiosity."

Dyslexia: Penfriend's Software claims to provide Homophone support - YouTube

Penfriend software products claim to support you with Homophones.

A homophone is a word that is pronounced the same as another word but differs in meaning. The words may be spelled the same, such as rose (flower) and rose (past tense of "rise"), or differently, such as carat, caret, and carrot, or to, two, and too. 


Homophones that are spelled the same are also both homographs and homonyms.

Homophones that are spelled differently are also called heterographs. The term "homophone" may also apply to units longer or shorter than words, such as phrases, letters or groups of letters that are pronounced the same as another phrase, letter or group of letters.

Homophones, sometimes known as 'confusables' are words which have a similar sound but differ in spelling and meaning. Examples of homophones include 'there' and 'their', 'where' and 'were' and so on.

With over 400 homophones in the English language, similar sounding words add depth to a language but they can also be the cause of great frustration. Spell checkers can't even be relied upon where these troublesome homophones are concerned.

The problem with most homophones is that if you're typing too quickly or not paying close attention to what you're writing, you could accidently end up with a properly spelled word, except it's the wrong word. Confusables are often highlighted by dyslexic people as a source of annoyance and confusion.

With Penfriend's new 'Confusable word hints' you can now see and even hear the difference between confusable words so there's no excuse to get 'pair' and 'pear' or 'bear' and 'bare' mixed up anymore.

NB: This website does not endorse or recommend products or services, this information is provided to allow you to access and make informed decisions.

BishopBlog: Phonics screening: sense and sensibility

There’s been a lot written about the new phonics test that is being introduced in UK schools in June. 

Michael Rosen cogently put the arguments against it on his blog this morning. 

A major concern is that the test involves asking children to read a list of items, and takes no account of whether they understand them. Indeed, the list includes nonwords (i.e. pronounceable letter strings, such as "doop" or "barg") as well as meaningful words. 

So children will be “barking at print” - a very different skill from reading for meaning.

I can absolutely see where Rosen is coming from, but he’s missing a key point. You can’t read for meaning if you can’t decode the words. 

It’s possible to learn some words by rote, even if you don’t know how letters and sounds go together, but in order to have a strategy for decoding novel words, you need the phonics skills. 

Sure, English is an irritatingly irregular language, so phonics doesn’t always give you the right answer, but without phonics, you have no strategy for approaching an unfamiliar word. 

Read more of this article here: Phonics screening: sense and sensibility

Can Playing Maternal Voice and Heartbeat Sounds Benefit Premies?

Nearly five years ago, Amir Lahav became a parent of twins born prematurely at 25 weeks. They weighed just over 1 pound each.

Welcoming two newborns into the family certainly changed his life, but as a neuroscientist, it also ended up changing the course of his research.

Lahav studies how the brain processes sounds, and worked primarily with neurologically impaired adults, but with the birth of his twins, his paternal instinct kicked in.

He approached the chief of newborn medicine at Brigham and Women’s Hospital in Boston, where the babies lay in incubators.

“Could I put a recording of my wife's voice in there?” Lahav asked, convinced that hearing their mother’s soothing tones would improve the babies’ development. The answer: It's certainly worthwhile.

Using his computer, Lahav recorded his wife’s voice telling the babies they’re fighters and urging them to be strong.

He also included some soothing piano music, figuring it could prove relaxing for preemies. Then he tinkered with the sound to make it resemble what a baby would hear in utero.

While we hear through air, babies in the womb process sound through fluid so what passes as hearing consists of more low-frequency vibrations. (Think about slipping beneath the surface of the bath as someone talks to you, or try speaking while putting a finger in each ear.) “It’s as if babies are living in a micro-subwoofer,” explains Lahav.

The twins seemed to like the recordings, and doctors and nurses in the neonatal intensive care unit (NICU) were intrigued.

Moreover, it proved therapeutic for Lahav and his wife. “It was not a controlled trial,” says Lahav, “but just a crazy father trying to do something because especially in the case of premature babies, you feel very helpless.”

Once his twins left the hospital, Lahav returned to thank the chief for letting him experiment.

One thing led to another, and they found themselves in a serious conversation about prematurity and how the focus of neonatal medicine has changed from saving the lives of these babies, doctors have grown expert at keeping preemies alive, to helping them grow into healthy children.

Studies have shown that premature infants are at greater risk of having low IQ and developing metabolic or chronic conditions in young adulthood that can shorten their lives.

Could keeping them bathed in mom’s comforting sounds lower the incidence of some of these adverse effects on their health? Lahav wound up with a job offer to find out.

Read more: Can Playing Maternal Voice and Heartbeat Sounds Benefit Premies?

What is up with Noises? The Science and Mathematics of Sound, Frequency, and Pitch - YouTube

Mathemagician Vi Hart creates another brilliant stop-motion movie, this time exploring the science and mathematics of sound, frequency and pitch. From Pythagoras to the anatomy of the ear, Hart uses her signature playful hand-illustrations to reveal how simple mathematical ratios make pleasing melodies.

How to Learn about Letters and their Sounds

Teaching children how to read is based on the concept of letters and sounds. There are a few ways that you can help your child learn to read using simple strategies. When your little one begins to read on their own, you will feel amazed at the progress and feel thankful for all the work that was put into it.

Make a Sound Connection
Before a child can read, they have to make the connection between the sounds that letters make and the letter itself. Once a child realises that the sound and letter go together, it can be a helpful step toward putting sounds together.

There are lots of phonic books available that can help your child learn the steps toward reading independently. They will first begin to recognise that letters have sounds and begin to memorise what they are. A book that features fun activities for children, will increase their motivation and make them want to learn more.

Words Worth Repeating
A good phonics reading material will feature lots of repetition, so that your child really understands what is trying to be taught. The more practice they have with letters and sounds, the more they will comprehend what they are doing.

One step at a Time
Often a book will be broken down into several teaching strategies, it is recommended that a child learn one area of reading before starting a new topic. When a phonics book is divided into separate components, it can assist the child with learning in a way that suits their learning needs.

Practice, Practice, Practice
The best way to have your little one reading, is to practice every night. You can help them do some work sheets during the day, and then read together at night before bed. The more that reading takes place together, the higher the chance of early reading. Helping your child learn to read, takes patience and time.

If your child has a hard time picking up a new skill, then just keep going over the same concept until they understand it. When a child feels successful at something, they will be more inclined to stick with it.

More.......

Orthography: the relationship between written symbols and sounds

In our previous 2 blogs we discussed briefly the sounds of letters and the sounds found inside words; 'Print Awareness' and 'Phonics and Phonemics'.

Taking this a step forward, we would like to introduce you to another term that is often used in describing language and one that has a big part to play in the detection of Dyslexia and the difficulties a child may have in learning to read and spell in a specific language; Orthography.

Orthography

Orthographies are writing systems, the relationship between the words we speak and how we write that down. Conversely, it is how we interpret and speak the words and letters that we see written on a page.

Orthography in Languages

It may surprise you to learn that the orthography of some languages are easier to interpret and learn than others. The complexity of a language's orthography, or writing system, can be a significant contributing factor to the difficulties experienced by readers who suffer from Dyslexia.

Symbols in Language

Languages such as Chinese have very simple orthographies because it has a pictorial languagee. Their written language is based on symbols that represent a picture of the word. Dyslexia is unknown in China.

The difference in the complexity of language and it's symbols versus sound interpretation is best described as the depth of the Orthography.

Shallow orthographies
Shallow Orthographies have a more straightforward, one-to-one relationship between sounds (graphemes) and letters (phonemes), and the spelling of words is very consistent. Italian and Finnish, which are examples of shallow orthographies and consequently, children and new readers, have very little trouble learning to decode words and match them to their sounds.

As a result, children who wish to learn to read in those languages, do so relatively quickly and with greater ease. Most readers who suffer from Dyslexia and are learning to read in a shallow orthography, learn to decode words with relative ease. Unfortunately, they can experience more difficulty with reading fluency and comprehension.

The hallmark symptom of dyslexia in a shallow orthography is the speed of rapid automatised naming (RAN - the speed of recalling and naming an object, word or letter once it is recognised).

Deep Orthographies
Unfortunately, one of the languages considered to be 'deep' is English, as well as Arabic, for example. They do not have a one-to-one correspondence between sounds (phonemes) and the letters (graphemes) that are intended to represent those sounds. As a result, children learn to read more slowly and with the potential for introducing more difficulties.

Overcoming this difficulty
Research has shown that the symptoms of Dyslexia in a deep orthography are a deficit in phonological awareness and difficulty in reading at the word level. For these readers who suffer from Dyslexia, learning to decode words may take a long time but the good news is, that once some level of decoding has been overcome, many of these readers have relatively fewer problems with fluency and comprehension. This is the opposite of the 'shallow' orthographies.

Comparative Studies
Studies between German and English have shown that the greater depth of English orthography had a "marked adverse effect on reading skills" among dyslexic children.