Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Medical Help with info on Brain function vs intelligence

  1. Feb 13, 2007 #1
    I am working on a paper about dyslexia.

    It is interesting to me that, on the one hand, dyslexia is labeled as a disability or deficit, or a glitch in the brain. But on the other hand, data shows that these same kids have above average IQ.

    How can the brain be both - disabled and above average IQ. Are there other situations where this is true?

    I was fascinated by the conversation on Cerebral Glucose Metabolism as related to intelligence in a separate post, but it was a little over my head.

    I was hoping someone here could comment on all of this, but in more layman terms.

  2. jcsd
  3. Feb 13, 2007 #2


    User Avatar
    Homework Helper

    Since you are working on a paper, perhaps you know: is it true that people with dyslexia can't tell left from right?
  4. Feb 13, 2007 #3
    To answer Verty's question first:

    No, it is not true that people with dyslexia can't tell left from right. Some people with dyslexia are late to establish hand dominance -- but so are people without dyslexia, so that's not a fool-proof clue. Some people with dyslexia also show delays in "Rapid Automatic Naming" (RAN)-- essentially, speed of recall. We all have occasional difficulty with RAN; think of a time when the word's been on the tip of your tongue, but you can't quite get it. People with RAN difficulties may have difficulty responding correctly to an instruction to "pick up your left foot" for example. It is as if they have to stop and think, "Now, which one is my left foot? Oh, yeah!".

    A good model for RAN difficulties might be a computer that is need of defragmenting. The processor is as powerful as ever, but the pieces of program are scattered all over, leading to slowed performance. Sadly, there's no program to defragment the human brain, yet.
  5. Feb 13, 2007 #4
    Dyslexia Vs Intelligence

    I am going to cut you some slack and believe that you meant average or above average intelligence because that is what is most commonly written. Seldom does anyone write that all dyslexics are above average and never have I seen any generated data that suggests that.

    Please show the DATA that dyslexics are usually of average or above intelligence. Many myths are associated with dyslexia and that is one of the most common. It is an historical concept that started when it was noticed that some intelligent people had major difficulties with reading. That progressed to looking for intelligent people that had reading problems to find dyslexics to study. From there it became a sampling bias.

    Change your data to say diagnosed dyslexics are usually of average or above average intelligence and it would be true. You could also say that diagnosed dyslexics are usually from average to above average income families and be equally true. This is also because of a sampling bias as families with more money are more likely to have their reading impaired child tested which also skews the results. This doesn't mean there are not any poor or low IQ dyslexics just that you won't find very many because they are not likely to be diagnosed.

    Only in Lake Woebegone where all the children are above average could it possibly be true. ( from the NPR radio show )

    Imagine a bell curve for any characteristic. Now cut it in half. Try explaining how the curve could possible be true. Bell curves reflect natural variations and pretty much define how differences occur and have an average value part at the peak and then decline to lower numbers at smaller concentrations to the left and higher numbers at lower concentrations to the right. Nature seldom makes exceptions to this and there is no compelling reason why dyslexia would be any different.

    There is an additional problem to consider and that is at lower IQs it becomes more difficult to tell if the poor reading skills are caused by dyslexia or lower IQ. By the time you get to an IQ of 70 the expectations of reading skills are so low that if he or she is dyslexic the added reading problems would be easily missed.

    I have read much of the dyslexia research over many years and while I have read many many times about how dyslexics usually have average or above average intelligence I have never been able to find any study to support this. In fact researchers that are interested in the question are finding no support for that conclusion.

    When writing a paper I hope you don't use the word data to actually mean 9 out of 10 websites about dyslexia say that dyslexics usually have average or above intelligence.

    If you think about what "usually of average or above average" means it actually means nothing for dyslexia. Think about it. It allowes for the possibility of dyslexics being below average or it would say dyslexics are always. There are also no standards for reading skills below some lower IQ level so how would anyone know if some low IQ people were dyslexic ?

    BTW Crazy People aren't stupid because you usually have to think yourself crazy ( True or False )
  6. Feb 13, 2007 #5
    I'm not sure where you got your data, but it is not true that

    data shows that these same kids have above average IQ.

    According to Sally Shaywitz, MD


    (More recently, some people have been expressing curiousity about the incidence of dyslexia among people with IQs lower than 85 -- might it also occur independently of IQ, and might the underlying deficit account for some developmentally disabled folks' difficulty in learning to read at a level commesurate with their abilities?)

    I can understand your confusion, though. Let's go back in time, though, to the 1200s, when literacy was very rare, even among the elite. You meet a woman who impresses you with her broad knowledge and ability to think deeply. You'd think nothing of her illiteracy -- you probably are too, if you are a person living in 1200!

    Let's take another example of a problem with communication: stuttering. It too is a brain-based disability, but it isn't connected in the popular mind with poor thinking skills, the way reading delays are.

    What is dyslexia? The definition has shifted over time.

    This is the current one from the International Dyslexia Association. I am linking to Susan Barton's site, because she has some excellent videos on signs and remediation of dyslexia


    We now think that (again quoting Dr. Shaywitz):
    Noticing and manipulating the smaller sounds in a word is called phonemic awareness


    So if a child has normal hearing, but can't tease apart the separate sounds
    that make up a word (like /m/ /o/ /p/ in the example above, how will she not be befuddled by what comes next, the alphabetic principle?



    Here's more from Dr. Shaywitz:

    Myth: Children will outgrow dyslexia.
    Fact: Dyslexia is neurobiological in origin and, as suc, is a lifelong learning disability. Student with dyslexia can overcome their academic difficulties with early identification and intervent, but they will always have dyslexia.

    Myth: Students with dyslexia see letters and words backwards.
    Fact: Dyslexia is not a visual problem. Dyslexia does not cause students to see letters and words backwards. Some students may confuse similar letters, misread similar words, and have trouble forming letters due to their lack of phonological skills.

    Myth: Dyslexia is a general, catch-all term.
    Fact: Dyslexia is a specific learning disability that is neurobiological in origin. In the United States, the research-based definition of dyslexia adopted by the International Dyslexia Association and supported by the National Institutes of Health provides clear delineation of the characteristics of dyslexia.

    Myth: There's no such thing as dyslexia, just parents making excuses for their children who are too stupid to learn to read
    Fact:: Children with

    Myth: Dyslexia only occurs in English-speaking countries, and that is proof that dyslexia doesn't exist.
    Fact: Research has shown that there is a universal neurocognitive basis for dyslexia. Differences in reported incidence may have at two causes: (1) cultural and pedagogical features unique to a country (2) Countries whose dominant language has shallow orthography may allow better reading performance from some dyslexics.

    Myth: Dyslexia is very rare.
    Fact: The prevalence of dyslexia is between 10% and 15% of any population.

    Myth:Only boys have dyslexia
    Fact: Good evidence based on sample surveys of randomly selected populations of children now indicate that dyslexia affects boys and girls equally; the long-held belief that only boys suffer from dyslexia reflected sampling bias in school-identified samples.

    Myth: My second grade student X cannot have dyslexia, because she can read some sight words / is reading at grade level
    Fact: Many dyslexic children have memorized some sight words, enough to escape detection by teachers who believe this myth. Some students' reading difficulties are not apparent to unsophisticated observers until third grade or later, when the demands of reading increase. However, difficulties with accurate spelling, difficulties with reading fluency, and other other clues will tip off the well-educated k-3rd grade teacher observer.

    Myth: Students with dyslexia cannot comprehend phonics, so they cannot be taught to read.
    Fact: This myth confounds "phonological awareness", "phonemeic awareness" and "phonics". "Phonological awareness" is the conscious sensitivity to the sound structure of language. It includes the ability to auditorily distinguish parts of speech, such as syllables and phonemes. The ability to blend and segment phonemes is critical to the development of decoding and spelling skills. Phonological awareness is an important and reliable predictor of later reading ability. "Phonemic awareness" is most simply described as "the insight that every spoken word can be conceived of a sequence of separate sounds (National Research Council, 1998)."

    With early identification and effective research-based, intensive, systematic, multi-sensory, structured-language intervention designed specifically for students with dyslexia, these students can learn to read and/or write well.

    Myth: Dyslexia cannot be identified until the child has been in school for four years (In the United States: third grade).
    Fact: Early intervention is critical to the success of students with dyslexia. Educators need to assess kindergartners' phonemic awareness, letter knowledge, speed of naming, and sound-symbol matching because these skills predict reading success in first and second grade. Dyslexia can be identified with certainty by mid-point of first grade after students have been exposed to effective reading instruction.

    Myth: Dyslexia is a medical or clinical problem, so schools cannot address it. Only medical doctors or psychologists can diagnose dyslexia.
    Fact: Dyslexia is a learning disability which should be noticed by educators. Students suspected of having dyslexia should be referred to qualifed professionals (typically, psychologists with PhD qualifications) who have expertise in (a) in how students process language and learn to read, (b) why some students have difficulty learning to read, and (c) adminstering psychoeducational batteries of tests that can discern students' difficulties.

    Myth: Dyslexia didn't exist (a) before television (b) when mothers stayed home and were available to read to preschool children (c) when teaching was better in some "golden age" prior to the present time.
    Fact: The concept of a developmental reading disability was first recognized in 1877 by Kussmaul and confirmed by James Hinshelwood in 1896. The term dyslexia came into general use in the 1960s.

    Myth: There are simple ways to identify dyslexia
    Fact: There is no single test for dyslexia. A comprehensive battery of tests must be administered. This battery should address phonological processing, oral language, letter knowledge, decoding, word recognition, reading fluency, reading comprehension, spelling, written expression, and cognitive functioning. Information should also be collected regarding the student's developmental and family histories.

    As our knowledge of dyslexia increases, some less-comprehensive screening tests may be found to be reliable. "Screening" is different from "diagnosis".

    Myth: If the dyslexic student would just try harder, she would succeed.
    Fact:This is exactly the same as sayig to a child with 20/200 vision, "You don't need glasses. Just try harder to see what isn't clear to you." The child with such vision deficits has a biological variation in her eyes, which requires a skilled intervention that has become common -- we call them "glasses" or more formally, "corrective lenses". A child with a neurobiological variation we now call dyslexia needs a similar intervention. It is not within the control of the dyslexic child. Motivation is not the primary problem for the student with dyslexia but rather may become a secondary problem because of continued lack of success in academic endeavors.

    Myth:Dyslexia is caused by poor teaching or exposure to the "whole language" or "balanced literacy" approach to reading.
    Fact:Poor instruction does not cause dyslexia but can exacerbate the reading difficulty. Conversely, effective instruction promotes reading success and alleviates many difficulties associated with dyslexia.

    Myth:Dyslexia is a special education issue and should be dealt with through the special education process.
    Fact:The crucial fact for for students with dyslexia is to have early identification followed by effective, research-based instruction designed for students with dyslexia. Dyslexia intervention is most effectively provided within the school's regular education program as a Tier III Intervention.

    Effective Teaching to Remediate Dyslexia--These steps must be mastered in order!

    Phonemic Awareness is the first step. You must teach the student how to listen to a single word or syllable and break it into individual phonemes--the individual sounds.

    Phoneme/Grapheme Correspondence is the next step. Here you teach which sounds are represented by which letter(s), and how to blend those letters into single-syllable words.

    The Six Types of Syllables that compose English words are taught next.

    Probabilities and Rules are then taught. The English language provides several ways to spell the same sounds. For example, the sound /SHUN/ can be spelled either TION, SION, or CION. The sound of /J/ at the end of a word can be spelled GE or DGE. Dyslexic students need to be taught these rules and probabilities.

    Morphology and Roots and Affixes--Morphology is the study of how morphemes are combined from words. A morpheme is the smallest unit of meaning in the language. The curriculum must include the study of base words, roots, prefixes, and suffixes.

    How it is taught:

    Simultaneous Multisensory Instruction: Sometimes we rattle this off and don't really explain what it means or why it is important

    This can be confusing to parents

    Sight or seeing, using the eyes = VISUAL

    Hearing or listening, using the ears = AUDITORY

    Feeling or touching, using the skin = TACTILE

    Moving through space and time, using the whole body = KINESTHETIC

    Reading and writing go together; writing is a kinesthetic task--(can you feel how all the muscles in your hand and arm work to form letters as you write a sentence?).

    Dyslexic people who use all of their senses when they learn (visual, auditory, tactile, and kinesthetic) are better able to store and retrieve the information. So a beginning dyslexic student might see the letter A, say its name and sound, and write it in the air -- all at the same time.

    Excellent instruction includes:

    Intense Instruction with Ample Practice: The dyslexic brain benefits from overlearning--having a very precise focus with lots and lots of correct practice.

    Direct, Explicit Instruction: dyslexic students do not automatically get anything about the reading task, and may not generalize well. Therefore, each detail of every rule that governs written language needs to be taught directly, one rule at a time. Then the rule needs to be practiced until the student has demonstrated that she has mastered the rule in both receptive (reading) and productive (writing and spelling) aspects. Only then should the instructor introduce the next rule.

    Systematic and Cumulative: Many dyslexic students are not identified until later in their academic careers. They have developed mental structures of how English works that are completely wrong. To develop good written language skills--reading and writing--the tutor must go back to the very beginning and rebuild the student's mastery with a solid foundation that has no holes or cracks.

    Synthetic and Analytic: dyslexic students must be taught both how to take the individual letters or sounds and put them together to form a word (synthetic), as well as how to look at a long word and break it into smaller pieces (analytic). Both synthetic and analytic phonics must be taught all the time.

    Diagnostic Teaching: Teachers must continuously assess their students' understanding of, and ability to apply, the rules. The teacher must ensure the student isn't simply recognizing a pattern and blindly applying it. And when confusion of a previously-taught rule is discovered, it must be retaught.

    More Reputable Sources:

  7. Dec 28, 2010 #6
    There is no such thing as a learning style; that is, no such thing as auditory, visual, tactile or kinesthetic preferences when learning. All normal children use all senses as needed.

    If dyslexics can be taught to read by the method that works best for all children (based on an understanding of the letter/sound associations) then what makes a child uniquely dyslexic? All children have difficulty learning to read if not taught that letters represent sounds; all children are therefore dyslexic if inadequately or improperly instructed. If dyslexics have difficulty reading then proficient readers are not dyslexic; if dyslexics can become proficient readers, they are no longer dyslexic.
  8. Dec 28, 2010 #7


    User Avatar
    Gold Member

    see "savant syndrome"

    It's not particularly surprising, since the brain consists of many different regions and systems specialized for many different functions and integrated with a variety of quality in redundancies.

    It is known that blind people who no longer use their visual processing regions for visual processing begin to use those regions for processing other sensory signals that are still available to them.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?

Similar Discussions: Help with info on Brain function vs intelligence
  1. Brain Function (Replies: 2)

  2. Mind vs brain (Replies: 6)

  3. Left vs Right Brain (Replies: 22)