See Brain. See Brain Read...
New advances in brain-imaging technology are helping scientists discover what happens in the brain when children read. By comparing the images of children who are known to have reading difficulties with those of children who are strong readers, researchers are learning more about how to help children overcome reading problems. Furthermore, images that show what happens to children's brains before and after they get systematic, research-based reading instruction show that the right teaching methods can normalize brain function and thereby improve a child's reading skills.
As many as one out of every five children has a significant reading disability, according to the National Center for Learning Disabilities. Reading disorders, which affect boys and girls equally, can cause difficulties in school and into adulthood. The most common reading disorder, dyslexia, affects an estimated 13 percent to 14 percent of the school-aged population, according to the International Dyslexia Association.
Many children with reading disorders have trouble with a process called “decoding” — essentially, figuring out the different sounds assigned to different letters, and correctly applying those letter-sound relationships to pronounce written words. In the first stage of scientific reading research, experts hypothesized that decoding difficulties were caused by a problem in the brain, and had more to do with sound than with sight. Brain-imaging studies confirmed that hypothesis, joining other psychological studies in establishing that dyslexia does not reflect visual problems or lower intelligence.
Now, psychologists are learning more about what happens in the brain during reading — and testing whether certain kinds of reading instruction can actually change the brain.
Sally Shaywitz, MD, and Bennett Shaywitz, MD, of Yale University, showed that when children without reading problems tried to distinguish between similar spoken syllables, speech areas in the left brain worked much harder than matching areas in the right brain. But when children with reading problems made the same attempt, those parts of the right brain worked harder, going into overdrive after a brief delay. In a 2004 study, the Shaywitzes found that when second- and third-grade students with dyslexia learned to read through an experimental eight-month intervention, those critical left-hemisphere areas became active, looking more like the brains of normal readers.
In a 2005 study, Panagiatos Simos, PhD, of the University of Texas Health Science Center at Houston, and colleagues used technology called magnetic source imaging (MSI) to compare brain activity patterns of kindergartners with either good or poor pre-reading skills. Then they followed the children into first grade. The images showed that children who became skilled readers by the end of first grade had, as early as kindergarten, effective brain-activation patterns for reading. Children who had a bumpier start with reading skills showed different patterns. However, 13 of the 16 children with reading difficulties responded to systematic reading instruction. After a year of direct instruction in the "alphabetic principle" (how letters work together to make words), comprehension (the meaning of words) and fluency (accurately reading words aloud), the students with previous reading difficulties became average readers. What's more, the MSI images showed that during the course of first grade, the children's brains started to bring critical reading areas — areas they hadn't used before — into the reading process.
More recently, scientists have found that brain activity isn't the only thing that differs between children who read well and those who experience reading difficulties. For example, Guinevere Eden, PhD, at Georgetown University, and colleagues found that children with dyslexia don't just have different levels of activity within certain brain regions; they also show poorer connectivity between brain regions. And that connectivity can improve following targeted reading instruction, they found. Researchers at the University of Washington, meanwhile, have used brain imaging to show that children with dyslexia show an increase in their brain's gray matter — the bodies of brain cells — after intensive reading training. The increase in gray matter volume corresponded with reading improvements.
Other studies have identified brain differences among children who respond to reading intervention and those who don't. In 2007, for example, Simos' team used MSI to look at brain activation in 15 first-graders with severe reading disabilities who hadn't made progress despite quality reading instruction. The children received intensive instruction that focused on skills such as phonological decoding (figuring out how to pronounce a word) and rapid word recognition. Eight of the children showed significant improvement in reading ability, and MSI results confirmed that their brains had begun to function more like those of “normal” readers. The seven children who did not improve in reading ability also failed to show the “normalizing” changes in their brains. Such findings may lead to more targeted interventions for specific reading disorders.
Research also suggests that improvements from reading instruction persist. A 2008 study found that compared to good readers, poor fifth-grade readers had lower activity in a region of the brain called the parietal cortex. After intensive instruction, the poor readers showed increased activity in portions of that region. One year after the intervention, that activity had continued to increase, resulting in normal levels of brain activation.
Reading research has made significant progress over the past 30 years, accelerating in the last decade as researchers who study interventions collaborate with brain-imaging researchers. Many studies over the last three decades have confirmed that reading difficulties are often caused by specific brain-based differences in how children process information.
By using brain images to study reading, psychologists and their colleagues in medicine and education have found a biological explanation for the 2004 finding that research-based teaching can significantly improve how students with dyslexia read and spell. Researchers have also found evidence that effective instruction normalizes brain function.
Just as promising is the research that shows children who might otherwise have trouble learning to read can be identified early and taught before their reading problems are apparent. With targeted interventions, their brains can change in as little as a year. This news is encouraging: Most kids who are at risk for reading problems can still learn to read.
Research has underscored the importance of quality instruction in reading basics: comprehension, phonological awareness, the alphabetic principle and the rules of spelling and writing. Children as young as early kindergarten — if not younger — should be screened to determine their level of risk for reading difficulties, and research-based reading programs should be incorporated in the elementary-school curriculum. A child who is at risk may need more intense instruction, but the earlier the better.
Cited research and further reading
Blachman , B. A. (1994). What we have learned from longitudinal studies of phonological processing and reading, and some unanswered questions. Journal of Learning Disabilities, 27 (5), 287.
Blachman , B. A., Fletcher, J. M., Schatschneider, C., Francis, D. J., Clonan, S. M., Shaywitz, B. A., Shaywitz, S. E. (2004). Effects of intensive reading remediation for second and third graders and a 1-year follow-up. Journal of Educational Psychology, 96 (3), 444-461.
Breier, J. I., Simos, P.G., Fletcher, J. M., Castillo, E. M., Zhang, W., & Papanicolaou, A.C. (2003). Abnormal activation of temporoparietal language areas during phonetic analysis in children with dyslexia. Neuropsychology, 17 (4), 610-621.
Foorman, B., Fletcher, J. & Francis, D. (1997). A scientific approach to reading instruction. Learning Disabilities Online.
Krafnick, A. J., Flowers, D. L., Napoliello, E. M., and Eden, G. F. (2011). Gray matter volume changes following reading intervention in dyslexic children. NeuroImage, 57 (3), 733-741.
Meyler, A., Keller, T. A., Cherkassky, V. L., Gabrieli, J. D. E., Just, M. A. (2008). Modifying the brain activation of poor readers during sentence comprehension with extended remedial instruction: A longitudinal study of neuroplasticity. Neuropsychologia, 46 (10), 2580-2592.
The NICHD Research Program in Reading Development, Disorders and Instruction (1999). The National Center for Learning Disabilities. Retrieved from http://www.ncld.org/students-disabilities/ld-education-teachers/nichd-research-program-reading-development-disorders-instruction.
Richards, T. L., Berninger, V. W. (2008). Abnormal fMRI connectivity in children with dyslexia during a phoneme task: Before but not after treatment. Journal of Neurolinguistics, 21 (4) 294-304.
Shaywitz, B. A., Shaywitz, S. E., Blachman, B. A., Pugh, K. R., Fulbright, R. K., Skudlarski, P., et al. (2004). Development of left occipitotemporal systems for skilled reading in children after a phonologically-based intervention. Biological Psychiatry, 55, 926-933.
Shaywitz, S. E. (1996, November). Dyslexia. Scientific American, 77-83.
Shaywitz, S. E. (2003). Overcoming Dyslexia: A new and complete science-based program for reading problems at any level. New York: Alfred A. Knopf.
Simos, P. G., Fletcher, J. M., Sarkari, S., Billingsley, R. L., Castillo, E. M., Pataraia, E., Francis, D. J., Denton, C., Papanicolauo, A. C. (2005). Early development of neurophysiological processes involved in normal reading and reading disability: A magnetic source imaging study. Neuropsychology, 19 (6) 787-798.