Monday, March 29, 2010

Ready to Read? Neuroscience Research Sheds Light on Brain Correlates of Reading

Ready to Read? Neuroscience Research Sheds Light on Brain Correlates of Reading
By Brenda Patoine


"While a high-level cognitive skill such as reading may seem like a natural province of brain research – all learning occurs in the brain, after all, and learning disabilities have clear brain correlates – until recently relatively few neuroscience laboratories have focused efforts on investigating the brain basis for this uniquely human skill. As neuroscience now delves into the neurobiology of reading, one thing is becoming clear: not all children’s brains are “wired” for reading in the same way.

Researchers are finding increasing evidence linking reading ability to subtle differences in the neural pathways. These pathways connect and coordinate brain regions involved in the elemental skills that comprise reading proficiency, from visual recognition of letters and words to phonological processing, to higher-level systems that enable content comprehension.
In particular, new techniques in neuroimaging are beginning to shed light on the neurobiological underpinnings of “reading readiness” and subtle brain differences that may help explain the wide variance of reading proficiency among children. These emerging data are illuminating the neural bases for the longstanding observation that reading abilities run a wide gamut from exceptional to below normal – the latter sometimes dipping to a level that society typically terms as reading-disabled.
But some researchers are wary of labeling kids as such, with all the consequent implications for academic stigmatization, lowered self-esteem, and family strife, and prefer to think of high- and low-achieving readers as merely at opposite ends of a normal distribution of skill proficiencies.
“My perspective, after 40 years of working on this entity we call ‘reading disability’ or ‘dyslexia,’ is that we need to be thinking of it as a variant of normal, rather than an abnormality,” said Martha Bridge Denckla, a research scientist at the Kennedy Krieger Institute, professor at Johns Hopkins School of Medicine, and member of the Dana Alliance for Brain Initiatives. She suggests reading can be better understood as a talent, a biologically bestowed gift that is not doled out equally to everyone.
“There is variability at the highest level of the brain for a whole bunch of different things we call talents,” said Denckla. “We accept completely that there are people who do not have whatever the neurological basis for musical talent may be – we just say they don’t have that ‘ear’ for music. Well, people can also be born with an untalented ‘ear’ for the speech sounds of language, which makes it very difficult to connect with an alphabetic system and be proficient at reading.”

An ‘Inconvenient Difference’

Rather than a disability, Denckla prefers to think of people who have difficulty reading as having an “inconvenient difference in biological organization” – though she is quick to point out that the disability moniker is crucial for enabling struggling kids to get the help they need in the education system because of the way special-education laws are set up.
Stanford University psychologist Brian Wandell echoed this sentiment: “Historically, people have assumed that all children’s brains come adequately equipped and ready to learn to read,” just as with learning to speak, which occurs naturally without much training. But, he said, “Sometimes, there is a natural distribution of capabilities. Reading is probably the hardest thing we teach people to do in the education system. There are some kids who are just going to have a hard time.”

Taken as a whole, Denckla said, these results suggest that in children who have difficulty reading, “the brain’s ‘wiring diagram’ is just a little bit different, better thought of as an anomaly than an abnormality. For all we know, it may have some benefit for some other activities, but it appears to be somewhat disadvantageous for reading.”
There are many examples, she pointed out, of highly successful people who are not so great at basic academic skills like reading, from Albert Einstein to Charles Schwab. “It turns out that the talent for reading – and particularly for reading quickly, which makes it useful – is not distributed to every human being, and not in direct proportion to one’s other talents,” Denckla said.

“If these fibers are weak, it may be that the signals aren’t coming in strong enough, or at the proper rate,” he said. Using larger text or three-dimensional characters, for example, or somehow manipulating the timing of the textual inputs, might “amp up the signal” enough to make a difference, he said. A similar principle has been used successfully to remediate language-based learning disabilities."

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