Understanding the Nature-Nuture Interactions in Language and Learning Differences

Abstract

Dr. Bernice Wong, editor of the Learning Disability Quarterly, invited this special issue in response to the growing interest in the biological factors in language and learning differences. Many professionals in the field of learning disabilities do not have the necessary training to be critical consumers of such research, for example, in genetics and the various brain-imaging technologies. In addition, there is often a long delay between publication of genetics and brain-imaging research findings in peer-reviewed journals and the trickle-down of these findings to practitioners or researchers who specialize in areas other than the biological factors in language and language differences. Furthermore, some professionals who are enthusiastic about biological explanations of language and learning differences do not have first-hand experience in genetics or brain-imaging research and may embrace brain-based educational bandwagons naively and uncritically. Therefore, I invited representatives of five biologically oriented research approaches to write articles for this special issue and gave them a threefold charge. First, I asked each to provide a tutorial on their major research tool for investigating biological influences on language and learning for readers in other fields who have not had training in genetics, neuroanatomy, brain imaging, electrophysiology, or cognitive neuroscience. Second, I asked each to provide a succinct summary of current research understandings in their respective fields regarding language and learning differences. Third, I asked each of them, as researchers with expertise in the biological bases of language and learning differences, to discuss some of their own recent research. Although each contributor was given the charge of writing about his or her biological research, each addressed, without any solicitation, the issue of interactions between biological and environmental factors. Wendy Raskind, M.D., Ph.D, a medical geneticist, emphasized that even if a screening test materializes some day for biologically based reading disorder, it will probably identify those who are at-risk for reading problems rather than diagnose reading disability. It is still the case that quality of reading instruction plays a critical role in preventing and lessening the severity of reading disability. Christiana Leonard, Ph.D., a neuroanatomist, showed that not only physical properties of the brain but also socioeconomic indicators of environmental factors predict performance on reading and language measures. Todd Richards, Ph.D., a neurophysicist, stressed the importance of conducting functional imaging at a developmental stage when reading problems are treatable and preventable -- because not only are there brain differences between those who learn to read easily and those who struggle in learning to read, but the brain may also change in response to learning to read. Dennis Molfese, Ph.D., and Victoria Molfese, Ph.D., are developmental psychologists who have combined electrophysiological and behavioral methods in longitudinal studies to demonstrate that brain recordings of newborns can predict language and reading problems in the preschool and school age years, respectively. Their research tool may be used to identify at-risk children for very early intervention. Finally, James Booth, Ph.D., a cognitive neuroscientist associated with the pioneering program in learning disabilities at Northwestern University, makes the important point that none of the biological methods yields data interpretable without a model of cognition and language based on paradigms in which individuals process incoming information from the environment. …