New research on the neural system of language

Neuroscientists have long known that particular areas of the brain are responsible for the comprehension and production of language. But new research points to the criticality of pathways between these areas for various components of language.

From a Science Daily article summarizing the research:

Two brain areas called Broca’s region and Wernicke’s region serve as the main computing hubs underlying language processing, with dense bundles of nerve fibers linking the two, much like fiber optic cables connecting computer servers. But while it was known that Broca’s and Wernicke’s region are connected by upper and a lower white matter pathways, most research had focused on the nerve cells clustered inside the two language-processing regions themselves.

MRI image shows Brocca's (yellow) and Wernicke's (purple) regions, connected by critical neural pathways. (Image credit: Stephen Wilson, Science Daily)

University of Arizona Professor of Speech and Hearing Stephen Wilson was one of the lead researchers:

If you have damage to the lower pathway, you have damage to the lexicon and semantics. You forget the name of things, you forget the meaning of words. But surprisingly, you’re extremely good at constructing sentences.

With damage to the upper pathway, the opposite is true; patients name things quite well, they know the words, they can understand them, they can remember them, but when it comes to figuring out the meaning of a complex sentence, they are going to fail.

Professor Wilson collaborated on the research with colleagues from the University of California at San Francisco and the Scientific Institute and University Hospital San Raffaele in Milan, Italy. The research was published in the journal Neuron.

Developing spatial vocabulary in infants

In a recent collection of essays, “Manhood for Amateurs,” one of my favorite writers, Michael Chabon, laments a development in the world of Legos, namely that they now come almost exclusively in kits with detailed instructions, designed to be assembled in a particular way to create a specific space ship or tractor. Gone, says Chabon, are the days of starting with a bin full of Legos of all sizes, shapes and colors, and creating, well, something creative.

Fortunately, some new research indicates that all might not be lost. In fact, “guided play,” in which participants are given blocks along with graphic instructions for creating a particular structure, generates higher levels of “spatial talk” than free play. The research was performed at Temple University’s Infant Lab, and recently highlighted by Science Daily:

The researchers found that when playing with blocks under interactive conditions, children hear the kind of language that helps them think about space, such as “over,” “around” and “through.”

“When parents use spatial language, they draw attention to spatial concepts,” said Nora Newcombe, co-director of Temple’s Infant Lab. “The development of a spatial vocabulary is critical for developing spatial ability and awareness.”

Spatial skills, says the Science Daily article, “are important for success in the STEM (science, technology, engineering and math) disciplines, but they are also involved in many everyday tasks, such as packing the trunk of a car or assembling a crib. They are a central component of intellect and, as those who struggle finding their way around a new city can attest, they show marked individual differences.”

So Chabon’s laments aside, it’s OK, and maybe even good, to pick up that Star Wars Lego kit and build the Death Star just like the picture on the box.

For other research about the importance of manipulative play, check out:

• Block-play May Improve Language Development In Toddlers
• Simple Retro Toys May Be Better For Children Than Fancy Electronic Toys

Ruminations of a brain scientist who also likes to party

Tuesday’s NY Times has a fascinating profile of Dr. Michael Gazzaniga, a professor of psychology at the University of California, Santa Barbara, who led pioneering research into the interaction of the various systems of the brain. Dr. Gazzaniga’s research focused on patients who had surgery to separate the hemispheres of the brain (used as a treatment for severe epilepsy). The research uncovered the presence of a left-brain-centered brain narrating system that creates a coherent voice from the inputs of many brain systems.

The Times article summarizes Dr. Gazzaniga’s research, but also provides some insight into the man who, among other things, was a member of the fraternity at Dartmouth that inspired the movie “Animal House”, and who says of his fellow researchers at Cal Tech “we weren’t intellectuals, in the sense that we were going out to see people lecturing or cultural events in the evening. That was martini time.” The profile of Dr. Gazzaniga by the Times is part of its series about leaders in science, and includes a video interview.

Dr. Gazzaniga’s new book, which examines the implications of the brain’s narrator for free will is called “Who’s in Charge? Free Will and the Science of the Brain.” It’s scheduled for release later this month.

Studying Japanese yields clues for kids with dyslexia learning English

The Wall Street Journal reports on recent research into the use of character-based languages such as the Japanese language kanji.

Learners with dyslexia struggle with the association between letters and sounds in English (a language in which words are comprised of groups of sounds that readers decode). However, character-based languages, where the characters represent complete words or ideas, are mastered through memorization, a skill that many students with dyslexia have mastered to compensate for their decoding struggles.

One study featured in the WSJ article looked at fMRI brain scans of dyslexic students and discovered that they use the same area of the brain to read English as do readers of kanji, a character-based Japanese language. This is different from the area of the brain used by typically developing English readers (and readers of kana, another Japanese language in which characters represent sounds instead of words or ideas).

As the article notes, we don’t cure dyslexia by teaching students in a character-based language. But it does offer some insight into how these kids’ brains are working differently and how teachers might be able to deliver reading-based content more effectively.

We have a link to a fantastic dyslexia study on our Web site. The study, performed at Stanford, is very consistent with the findings discussed in the WSJ article, as it supports the idea that students with dyslexia tend to make reading a more visual task, while typically developing readers integrate auditory processing as well.

 

Brain Fitness Program for Traumatic Brain Injury

Today’s NY Times reports on a planned study of the effectiveness of Posit Science’s Brain Fitness Program on veterans who suffered traumatic brain injuries (TBI) in combat. Posit Science was founded by Dr. Michael Merzenich, whose research into neuroplasticity forms the basis for the Fast ForWord programs.

Dr. Merzenich’s core claim is that brain structure is always changing, based on what people do and what they pay attention to. By doing specific brain exercises that focus and refine attention, he says, you can adjust the underlying structure of your brain. It is well established that this happens when we learn a new skill, like dancing. The question is, Can the same processes be employed to correct for brain damage?

Psychologists and others observing the study range from the cautiously optimistic (quoted in the Times, Gary Abrams, director of neurorehabilitation at U.C.S.F. and head of the T.B.I. support clinic at the San Francisco VA Medical Center, says “It is theoretically reasonable, but will it actually work to help veterans?”) to the skeptical (also cited, in the Times, Dr. P. Murali Doraiswamy, a Duke University psychiatrist, is “not convinced that gains translate into long-term benefits that can be generalized to daily challenges like remembering where the car is parked”).

The study will involve 132 veterans suffering from TBI. They’ll undergo a battery of cognitive tests before the program, and again 3 and 6 months after the program.

The Times article also makes a critical point that we frequently make about the neuroplasticity-based programs (Fast ForWord and Cogmed) that we use with struggling learners: the programs are different because they address the underlying cognitive deficits, rather than compensatory strategies.

Questionnaire can help with early identification of autism

A growing body of research suggests that early intervention is important for helping children with autism spectrum disorders. But early identification, which is critical for early intervention, has been somewhat elusive.

A new questionnaire, designed to be completed by parents in the pediatrician’s office during the one-year-old well-baby checkup, may help. Researchers from the University of California at San Diego had pediatricians distribute the 24-question survey to parents of 10,479 babies. The test identified 1,371 babies as potentially having autism or other developmental delay. The researchers tracked 184 of those, of whom 32 were subsequently were found to have autism spectrum disorder, 56 had language delays, 9 had developmental delays and 36 had other problems.

The survey is promising, but there was one challenge: 25% of the babies identified as potentially having developmental delays ended up on a normal development path. Such a high false-positive rate could result in a lot of unnecessary anxiety for parents.

The New York Times recently highlighted the research, which was published in the Journal of Pediatrics:

Although many pediatricians don’t screen 1-year-olds for autism, there is a growing body of evidence suggesting early intervention can be effective, said Dr. Karen Pierce, the lead author of the study — published Thursday in The Journal of Pediatrics — and assistant director of the Autism Center of Excellence at University of California, San Diego.

The checklist poses simple questions, like whether a baby responds to his or her name, whether parents can tell when an infant is happy or upset, and whether a child engages in pretend play with dolls or stuffed animals.

Great news! Parent’s language stumbles are good for kids!

It seems like most research studies we read about the impact parents have on the development of young children make us wish we had a do-over card. But here’s some refreshing news for those of us parents who doing the best we can: some of our mistakes can actually help our kids!

From Science Daily:

A team of cognitive scientists has good news for parents who are worried that they are setting a bad example for their children when they say “um” and “uh.” A study conducted at the University of Rochester’s Baby Lab shows that toddlers actually use their parents’ stumbles and hesitations (technically referred to as disfluencies) to help them learn language more efficiently.

For instance, say you’re walking through the zoo with your two-year-old and you are trying to teach him animal names. You point to the rhinoceros and say, “Look at the, uh, uh, rhinoceros.” It turns out that as you are fumbling for the correct word, you are also sending your child a signal that you are about to teach him something new, so he should pay attention, according to the researchers.

The conclusions are from a study published online on April 14 in the journal Developmental Science.

Quoted in the Science Daily article, lead study author Celeste Kidd, a graduate student at the University of Rochester, says “We’re not advocating that parents add disfluencies to their speech, but I think it’s nice for them to know that using these verbal pauses is OK — the “uh’s” and “um’s” are informative.”

If you’re interested in more about how parents can support their children’s language development, check out this post on the developing brain.

PBS NewsHour presents “Autism Now”

The PBS NewsHour just completed a 6-part series about autism. Causes, prevalence, research, funding: it’s all in there.

All six parts, as well as extended interviews with some of the experts are available on the NewsHour Web site, where you can also reserve a DVD of the series.

The Thirsty Linguist reviews Oliver Sacks’ latest book “The Mind’s Eye”

Doctor and author Oliver Sacks is known for bringing neuroscience to the masses. In The Man Who Mistook His Wife for a Hat and Awakenings (which was made into a movie starring Robert DeNiro and Robin Williams), Sacks explores neurological disorders with the writing skills of a novelist.

Our friend, the Thirsty Linguist, reviews Sacks’ latest book, The Mind’s Eye, which explores the human experience of vision:

As in some of his previous books, Sacks presents case histories of individuals suffering from neurological injury or disease, and uses these histories as a means to probe the capacities of the mind. Lilian Kallir, for example, is a pianist who loses the ability to read, even though the rest of her vision remains intact and, puzzingly, she can still write. Sacks follows Lilian’s story over a period of three years, describing the coping strategies she develops, such as color-coding items in her home, as well as the new talents that arise unexpectedly with her condition, such as the ability to re-arrange musical pieces in her mind without consulting a score. Howard Engel, featured in another case history, is a writer who also loses the ability to read, but he approaches his situation differently: he rejects audiobooks, refuses to give up the world of text, and painstakingly learns his ABCs all over again.

Lilian’s and Howard’s cases both suggest that the brain has a specific location dedicated to reading. But it is not at all obvious why this should be so. Unlike spoken language, which evolved over hundreds of thousands of years, written language is a relatively recent cultural invention that offered no survival advantage to humans in primitive societies. Plasticity offers a potential answer to this conundrum: we can and do use structures in the brain for purposes very different from those for which they evolved. Sacks casts a wide net to gather evidence for this idea. He describes case histories of nineteenth century neurologists, who treated patients with symptoms similar to Lilian’s and Howard’s. He cites evolutionary thinkers from Charles Darwin and Alfred Russel Wallace to Stephen Jay Gould and Elisabeth Vrba, tracing the history of the notion of “exaptation,” a biological adaptation which gets put to a new use. He presents key results from imaging studies which demonstrate that different areas of the brain are active during reading versus listening. And he summarizes a computational study of over 100 writing systems which shows that, despite their diversity, these systems share basic visual signatures which resemble those found in natural settings.

The Mind’s Eye thus offers narrative science writing of the most satisfying kind. We delight in pedagogical moments because Sacks weaves them seamlessly into the case histories. We get drawn into the topics of evolution, brain imaging, and computation because we want to follow people like Lilian and Howard. “Make characters the matter of your narrative,” advises James Shreeve in A Field Guide for Science Writers, “and let the science spill from their relations.” Sacks does precisely that.

If Sacks’ work intrigues you, you might also be interested in:

• Reading in the Brain by Stanislas Dehaene
• The Brain That Changes Itself: Stories of Personal Triumph from the Frontiers of Brain Science by Norman Doidge

It’s About Time…

Auditory processing describes what happens when the brain recognizes and interprets sounds. Humans hear when energy that we recognize as sound travels through the ear and is changed into electrical information that can be interpreted by the brain. For many students, something is adversely affecting the processing or interpretation of this information. As a result, these students often do not recognize subtle differences between sounds in words, even though the sounds themselves are loud and clear. For example: “Tell me how a chair and a couch are alike” may sound to a child struggling with auditory processing like “Tell me how a hair and a cow are alike.”

These kinds of problems are more likely to occur when the child is in a noisy environment or is listening to complex information.

The Temporal Dynamics of Learning Center (TDLC) at the University of California is one of six Science of Learning Centers funded by the National Science Foundation. Its purpose is “to understand how the element of time and timing is critical for learning, and to apply this understanding to improve educational practice.”

What is the role of timing in learning? From the TDLC Web site:

When you learn new facts, interact with colleagues and teachers, experiment with new gadgets, or engage in countless other learning activities, timing plays a role in the functioning of your neurons, in the communication between and within sensory systems, and in the interactions between different regions of your brain. The success or failure of attempts to communicate using gestures, expressions and verbal language also depend on timing.

In short, timing is critical for learning at every level, from learning the precise temporal patterns of speech sounds, to learning appropriate sequences of movements, to optimal training and instructional schedules for learning, to interpreting the streams of social signals that reinforce learning in the classroom.

Learning depends on the fine-scale structure of the timing between stimuli, response, and reward. The brain is exquisitely sensitive to the temporal structure of sensory experience:

• at the millisecond time scale in the auditory system;
• at the second time scale in reinforcement learning;
• at the minute time scale for action-perception adaptation; and
• at the day-to-week time scale for consolidation and maturation.

Each level of learning has its own temporal dynamics, and its own timing constraints that affect learning. These levels are not independent, but instead, timing constraints at one level affect learning at another level in a nested way. For example, the dynamics at the cellular level, which is often on the order of milliseconds, implement learning on the whole-brain and behavioral level on much longer time scales, including memories that last a lifetime.

The past decade of neuroscience research demonstrates that the intrinsic temporal dynamics of processes within the brain also reinforce and constrain learning. For example, we have discovered that slow learners tend to have slow “shutter speeds” in terms of how their brains take in and process information. For some poor readers, the underlying problem is the their inability to perceive fast acoustic changes in speech sounds (phonemes) that must be accurately perceived in order to learn letter-sound correspondence rules for reading.

Fortunately, says the TDLC Web site, “Neuroscience-based training regimes that improve this temporal processing ability improve both spoken and written language learning in struggling readers.”

One such training program is the Fast ForWord program, which can be an effective intervention for children with struggling with processing rates because it goes right to the cause of the problem, strengthening the gray matter in the area of the brain responsible for processing auditory information. With Fast ForWord, children are first exposed to sounds that are modified to enhance the minute acoustic differences between similar speech sounds. As children demonstrate proficiency and build new neural pathways, the program automatically reduces the level of modification, until eventually students are challenged to process normal speech sounds.

When their brains are processing speech sounds at peak efficiency, students can better  recognize and discriminate the rapidly changing sounds that are important for discriminating phonemes (the smallest units of speech that distinguish one word from another). As a result, they will more easily:

• Attend and respond to directions and class discussions
• Remember questions, directions, and information
• Learn to read and become a better reader