kitchen table math, the sequel: neuroscience
Showing posts with label neuroscience. Show all posts
Showing posts with label neuroscience. Show all posts

Monday, October 20, 2014

Neuromyths I have known and loved

In one study Dr. Howard-Jones cites, 48 percent of British teachers agreed with the statement “We mostly only use 10 percent of our brain.” Ninety-three percent believed that “individuals learn better when they receive information in their preferred learning style (for example, visual, auditory or kinaesthetic)” (research actually doesn’t support this), and 29 percent believed “drinking less than 6 to 8 glasses of water a day can cause the brain to shrink” (it can’t). Sixteen percent thought that “learning problems associated with developmental differences in brain function cannot be remediated by education.”

How Brain Myths Could Hurt Kids
I was able to pull the paper, and the data on teacher belief in learning styles is hilarious.

Percentage of teachers who believe individuals learn better when they receive information in their preferred learning style:

93% of teachers in the UK
96% of teachers in the Netherlands
97% of teachers in Turkey
96% of teachers in Greece
97% of teachers in China

Pretty much the entire planetary teaching force.

Sunday, November 9, 2008

Why McGuinness is Mistaken: Some Reading Problems ARE Biologically Based

In the post called "Why English-Speaking Children Can't Read", CJ quotes Dianne McGuinness, who baldly asserts that there is no biological basis to reading difficulties--it's all bad teaching.

While I respect and admire Professor McGuinness's contribution to education and her approach to the teaching of reading, her assertion is not supported by findings from cognitive neuroscience, particularly findings from functional magnetic resonance imaging (fMRI) studies comparing cognitive patterns of good readers and poor readers.

Further, reading and writing are complex, subtle biological activities -- crudely put, the eye must see, the brain must make sense of the visual stimuli; the brain must order the hand to perform a precise series of actions. A sophisticated and nuanced understanding of the neurocognitive nature of the processes, when they perform well, will bring us to understand where the breakdowns occur and how to remediate them.

I believe that Professor McGuinness's assertion is made without a full understanding of what fMRI studies have revealed abou the structure of the reading brain.

The researcher who has done the most to make the cognitive neuroscience accessible to lay readers is Marianne Wolf. I will quote from several sources to illustrate her findings:

From a Tufts University interview with Wolf:
According to Wolf, the brain never evolved to read. Rather, reading reveals how the brain "rearranges older structures devoted to linguistic, perceptual and cognitive regions to make something new." Children with dyslexia have a range of difficulties that prevent this.
Children of the Code interview with Maryanne Wolf --

Dr. Maryanne Wolf: The history of reading disabilities, (I'll use the word dyslexia - some people use it, some people don't), is such a fascinating one because it's like a case study in science patterns, the desire for parsimony among scientists and the refusal of the human brain to be typed in one way. What you see in this history is one researcher after another seizing on what is in front of them and saying, "Ah, that's what dyslexia is. That's what causes it." And it's really the most over-worked and even platitudinous analogy in the world. But the blind men and the elephant describe the history of dyslexia research.

David Boulton: And the Sufi key Story.

Dr. Maryanne Wolf: Exactly. If you look and put together even only the names of dyslexia, you'll see one hypothesis is visual, one is memory, one is verbal, one is auditory. You just go down the list. Well, if you put them all together, or if, as I'm doing this in a book now [Proust and the Squid], I just put those names on the brain and you see a crude cartography of reading. In other words, if it can go wrong it does. And at one point in the history of dyslexia each has been called the major explanation for dyslexia. Now, the modern history has been punctuated by really different, very technologically sophisticated approaches including neurosciences and also including a lot of wonderful work done in an area called psycholinguistics.

In the 1970’s there was a great set of researchers at Haskins Lab at Yale and they were really beginning a whole new approach to understanding dyslexia by looking at the linguistic foundations of reading breakdown. That began one of the single best hypotheses we've ever had which is that the phonological system in language, that is, our ability to hear, to discriminate the smallest sounds called phonemes in words is a fundamental necessity in learning to read and a fundamental source of why some children can't learn to read. That began what is called the phonological deficit hypothesis, which has really been the most successful of explanations to date.

Rapid Naming, Phonemic Awareness and Speed of Processing:

Dr. Maryanne Wolf: My research began while that hypothesis was in its zenith. At the same time I was equally influenced by neurosciences, which was then called neurological or neuropsychological studies. We were beginning to see that there was this one very odd phenomenon that children who were going to become dyslexic were always exhibiting, whether they were five or six or seven, and that was a failure to be able to name, it’s so simple, to name things they saw at the same speed that other children could.

Well, naming seems very simple but it's actually a very difficult set of underlying processes
. So, my mentor, Martha Denckla and her mentor, a neurologist, Norman Geschwind, were responsible for really getting the field to think differently, if you will. In the beginning, people said, "Well, naming speed is just another kind of phonology. You need to be able to retrieve a phonological label." And, for a while that satisfied me. Then, I began to see kids who had no phoneme issues in other areas and yet they had this....

David Boulton: You mean in terms of their ability to articulate themselves on the fly they would demonstrate that they had good phoneme processing but they couldn't name, which has an association component?

Dr. Maryanne Wolf: Well, that's really close. I'll just give you a slightly more technical explanation by saying that when we did all our tests we had explicit measures of these phoneme awareness skills that everybody says were the most important ones and we were seeing that some kids didn't have that but they had naming speed issues. Well, if they're both the same, they should have both. And they weren't exhibiting that and that began us thinking that there are so many issues beyond the phoneme, which includes the visual system and the retrieval system. It includes the speed with which the brain puts its systems together.

That was what we got fixated on. That's not the same as phoneme awareness. So, we then began to really get in-depth understandings of naming speed and the speed with which not only that you name but the speed with which you read and how that fluency in reading is really important not for speed as speed, but for the brain's ability to do those easy processes fast enough to allocate time to comprehension.

David Boulton: Right. So, those lower levels are operating efficiently and there's sufficient bandwidth to be reflective and comprehensive.

Dr. Maryanne Wolf: Perfect. That's what we were beginning to understand. So, this tiny little innocuous naming speed test opened up a world of understanding about how important all of these individual processes are that go beyond the phoneme and how important reading fluency is for comprehension. So, that puts you into, literally, a different ball park from the implication of the phonological deficit, which is that you work on words and phonemes and you get the kids to be able to recognize words and read, decode them and everything else is going to happen naturally. Well, it isn't that simple.

Double-Deficit Hypothesis and Interventions:

Dr. Maryanne Wolf: My colleague, Pat Bowers, and I, and others, (we weren't the only two), advanced our hypothesis in the early nineties. Back then we were kind of John the Baptist-types. It was a little hard going there for a while. Then people started thinking, we know they're right. We still believe it's phonology but there is no doubt that there are these kids. Here is where what we call the double-deficit hypothesis comes in: there are these kids who have single deficits in phoneme awareness, single deficits in naming speed without phoneme, and then double-deficit kids who have both. The kids who have both reading fluency and comprehension issues have different reasons for reading failure than the kids who have only phoneme awareness issues.

David Boulton: And therefore, need different interventions to differentiate their way through what’s obstructing their processing.

Do go read the rest of the interview.

More:
Excerpt from Proust and the Squid

Brain Science Podcast: Interview with Maryanne Wolf

California Literary Review: Proust and the Squid

Podcast: Moira Gunn Interviews Maryanne Wolf: Evolution of the Reading Brain

Guardian Review of Proust and the Squid

Link to description of the RAVE-O reading comprehension program and to description of one RAVE-O training program.

Monday, February 25, 2008

Ambition, Distraction, Uglification, and Derision

The Numbers Guy, Jim Holt, has a great piece in The New Yorker. In the article Are Our Brains Wired for Math? Holt discusses the work of the French neuroscientist, Stanislas Dehaene who argues that we are born with “number sense” that makes us capable of basic calculations and estimates. However, Dehaene clarifies, the procedures that we learn to carry out in mathematics are not instinctive at all.

The fundamental problem with learning mathematics is that while the number sense may be genetic, exact calculation requires cultural tools—symbols and algorithms—that have been around for only a few thousand years and must therefore be absorbed by areas of the brain that evolved for other purposes. The process is made easier when what we are learning harmonizes with built-in circuitry. If we can’t change the architecture of our brains, we can at least adapt our teaching methods to the constraints it imposes.

For nearly two decades, American educators have pushed “reform math,” in which children are encouraged to explore their own ways of solving problems. Before reform math, there was the “new math,” now widely thought to have been an educational disaster. (In France, it was called les maths modernes, and is similarly despised.) The new math was grounded in the theories of the influential Swiss psychologist Jean Piaget, who believed that children are born without any sense of number and only gradually build up the concept in a series of developmental stages.

[snip]

Piaget’s view had become standard by the nineteen-fifties, but psychologists have since come to believe that he underrated the arithmetic competence of small children. Six-month-old babies, exposed simultaneously to images of common objects and sequences of drumbeats, consistently gaze longer at the collection of objects that matches the number of drumbeats. By now, it is generally agreed that infants come equipped with a rudimentary ability to perceive and represent number. (The same appears to be true for many kinds of animals, including salamanders, pigeons, raccoons, dolphins, parrots, and monkeys.) And if evolution has equipped us with one way of representing number, embodied in the primitive number sense, culture furnishes two more: numerals and number words. These three modes of thinking about number, Dehaene believes, correspond to distinct areas of the brain. The number sense is lodged in the parietal lobe, the part of the brain that relates to space and location; numerals are dealt with by the visual areas; and number words are processed by the language areas.

And if evolution has equipped us with one way of representing number, embodied in the primitive number sense, culture furnishes two more: numerals and number words. These three modes of thinking about number, Dehaene believes, correspond to distinct areas of the brain. The number sense is lodged in the parietal lobe, the part of the brain that relates to space and location; numerals are dealt with by the visual areas; and number words are processed by the language areas.

Nowhere in all this elaborate brain circuitry, alas, is there the equivalent of the chip found in a five-dollar calculator. This deficiency can make learning that terrible quartet—“Ambition, Distraction, Uglification, and Derision,” as Lewis Carroll burlesqued them—a chore. It’s not so bad at first. Our number sense endows us with crude feel for addition, so that, even before schooling, children can find simple recipes or adding numbers. If asked to compute 2 + 4, for example, a child might start with he first number and then count upward by the second number: “two, three is one, our is two, five is three, six is four, six.” But multiplication is another matter. It is an “unnatural practice,” Dehaene is fond of saying, and the reason is that our brains are wired the wrong way. Neither intuition nor counting is of much use, and multiplication facts must be stored in the brain verbally, as strings of words. The list of arithmetical facts to be memorized may be short, but it is fiendishly tricky: the same numbers occur over and over, in different orders, with partial overlaps and irrelevant rhymes. (Bilinguals, it has been found, revert to the language they used in school when doing multiplication.)

The human memory, unlike that of a computer, has evolved to be associative, which makes it ill-suited to arithmetic, where bits of knowledge must be kept from interfering with one another: if you’re trying to retrieve the result of multiplying 7 X 6, the reflex activation of 7 + 6 and 7 X 5 can be disastrous. So multiplication is a double terror: not only is it remote from our intuitive sense of number; it has to be internalized in a form that clashes with the evolved organization of our memory. The result is that when adults multiply single-digit numbers they make mistakes ten to fifteen per cent of the time. For the hardest problems, like 7 X 8, the error rate can exceed twenty-five per cent.

Our inbuilt ineptness when it comes to more complex mathematical processes has led Dehaene to question why we insist on drilling procedures like long division into our children at all. There is, after all, an alternative: the electronic calculator. “Give a calculator to a five-year-old, and you will teach him how to make friends with numbers instead of despising them,” he has written. By removing the need to spend hundreds of hours memorizing boring procedures, he says, calculators can free children to concentrate on the meaning of these procedures, which is neglected under the educational status quo.

This attitude might make Dehaene sound like a natural ally of educators who advocate reform math, and a natural foe of parents who want their children’s math teachers to go “back to basics.” But when I asked him about reform math he wasn’t especially sympathetic. “The idea that all children are different, and that they need to discover things their own way—I don’t buy it at all,” he said. “I believe there is one brain organization. We see it in babies, we see it in adults. Basically, with a few variations, we’re all travelling on the same road.” He admires the mathematics curricula of Asian countries like China and Japan, which provide children with a highly structured experience, anticipating the kind of responses they make at each stage and presenting them with challenges designed to minimize the number of errors. “That’s what we’re trying to get back to in France,” he said.


It makes for fascinating reading. I still don't agree with the give a calculator to a five-year-old stuff, though. Nope. I just don't buy that.
Are Our Brains Wired for Math?
Jim Holt
The New Yorker
March 3, 2008