Perspectives on Language - Winter Edition 2011
Physical Exercise and Movement-Based Interventions for Dyslexia
Carolyn A. Denton 0000-00-00 00:00:00
Because of the extreme difficulty some children have with learning to read, educators and parents have sought alternative approaches to support this process. For several decades, various groups have proposed that programs of repeated movements or physical exercises would "normalize" the brain functioning of persons with dyslexia, enabling them to learn to read more easily. Since the 1960s, parents and schools have invested many thousands of dollars in these approaches, which have typically been offered through commercial enterprises. Risks and Benefits When any intervention or treatment is evaluated, two important questions must be addressed. First, does scientific evidence suggest that people are likely to benefit from the treatment? Second, is there a risk of negative effects? In biomedical research, the Food and Drug Administration requires tests to determine the relative benefits and potential negative side effects of experimental drugs. Standards are no less important in the treatment of children with dyslexia–the inability to read adequately has pervasive lifelong effects. The purpose of this article is to summarize the existing scientific research evidence regarding the effectiveness of exercise and movement-based therapies for children with dyslexia. No treatment approach can be considered effective based on one study; as in any scientific endeavor, it is the accumulation of evidence over time and the quality of each study that allows us to draw reliable conclusions about the effects of an intervention strategy. A high-quality intervention study a) is unbiased, b) is designed so that any improvement in performance can be attributed to the experimental intervention rather than to other influences (e.g., natural growth and development; additional instruction), c) uses high-quality and appropriate measures, d) provides evidence that the experimental treatment or intervention was actually implemented as intended (i.e., fidelity of implementation), e) employs appropriate methods to analyze data and report results, and f) interprets the results appropriately, not making statements that go beyond what the results actually show. General Effects of Exercise Clearly, regular physical exercise has many benefits in terms of fitness and health. There is also good evidence that regular aerobic exercise is associated with improved cognition (i.e., mental functioning) in adults, including improved executive functioning (Colcombe & Kramer, 2003; Hall et al., 2001; Kramer & Erickson, 2007). Executive functioning includes selfregulation, planning, switching attention from one thing to another, and maintaining attention on relevant stimuli while ignoring competing stimuli. Tomporowski, Davis, Miller, and Naglieri (2008) found evidence that regular physical exercise positively effects executive functioning in children, as well, although more research is needed to verify this. There is less evidence that regular exercise results in higher academic performance, as few researchers have examined this question using appropriate research designs. Children who participate in regular exercise programs over an extended period of time tend to have higher scores on achievement tests, but this does not necessarily mean that the exercise was responsible for the higher scores. It is possible that highly motivated students are more committed to exercising and are also more likely to have strong study habits that more directly result in higher achievement. Historical Basis of Movement-Based Treatments Movement-based approaches for children with dyslexia were proposed by several groups during the 1960s and 1970s. The most prominent were based on theories that learning disabilities are the result of neurological disorganization, a delay or failure to establish dominance of the left or right hemisphere of the brain, or problems with responding to visual, auditory, or motor stimuli. Early understandings of reading disorders correctly assumed that they were related to brain functioning, but the way the brain functions during normal and impaired reading was not well understood at that time. These early theories have since been disproven through behavioral and brain imaging research. However, intervention programs based on these theories remain commercially available today. Proponents of these training programs suggest that conditions including dyslexia, ADHD, intellectual disabilities, autism, and traumatic brain injury can be remediated through regular engagement in a prescribed sequence of repeated movements and various forms of sensory stimulation. Neurologic disorganization and repatterning. The theory of neurologic disorganization suggests that dyslexia and other disorders are caused by the failure of the nervous system to become properly organized during a child's early development and that the failure to complete early stages of development affects all subsequent stages. The theory also suggests that a disorganized nervous system can be "normalized" by returning to earlier developmental stages that had been skipped in order to "repattern" the brain by engaging in repeated movements designed to mimic prenatal and infant activities of normally-developing children. Repatterning may include having an adult manipulate a child's limbs to simulate these movements, sometimes over several hours per day (American Academy of Pediatrics, 1999). For example, a widely disseminated program developed by Doman and Delacato suggested that school-aged children who had failed to crawl before they learned to walk would benefit from engaging in repeated crawling movements (see Bird, 1967). Children undergoing Doman-Delacato therapy might also engage in sensory stimulation activities and rebreathing of air using a plastic face mask. Based on multiple, well-controlled studies, the American Academy of Pediatrics (American Academy of Pediatrics, 1982; American Academy of Pediatrics, 1999) issued two statements with strong warnings about the lack of evidence supporting neurologic disorganization theories and repatterning therapies, stating, "Treatment programs that offer patterning remain unfounded; i.e., they are based on oversimplified theories, are claimed to be effective for a variety of unrelated conditions, and are supported by case reports of anecdotal data and not by carefully designed research studies" (American Academy of Pediatrics, 1999, p. 1150). Hemispheric dominance. A second theory popularized during the early and mid-20th century suggested that reading disabilities were the result of delayed development of hemispheric dominance (as evidenced in right or left handedness). Samuel Orton (1925, 1937) attributed errors such as the reversal of letters (e.g., b/d) by poor readers and writers to delays in establishing hemispheric dominance, suggesting that mirror images of the symbols were stored in the left and right hemispheres of the brain (i.e., one hemisphere saw a b while the other saw a d) and that one hemisphere's perceptions could intrude on the other. Although Orton's contributions to the field of dyslexia are well recognized, his theories of hemispheric dominance have been disproven. Nonetheless, similar theories are still cited by commercial providers of training programs in which children participate in exercises such as crossing the midline (e.g., bouncing a ball with one hand and then the other while reaching over the middle of the body), suggested to remediate problems with hemispheric dominance. The perceptual deficit hypothesis. Another widely-accepted theory of the 1960s and 1970s proposed that learning disabilities are caused by visual, auditory, or motor-related perceptual problems. Like the proponents of neurologic patterning therapies, proponents of perceptual deficit theories suggested that learning disabilities could be remediated if children returned to processes associated with the early stages of perceptual development. Suggested interventions to correct perceptual deficiencies included fine- and gross-motor movement exercises. During the 1970s reading instruction was frequently withheld from students with learning difficulties until they had completed these therapies, on the assumption that children could not benefit from instruction until their perceptual problems had been remediated (Vellutino et al., 1977). Based on their review of research, Vellutino and his colleagues concluded that the perceptual dysfunction theory was ungrounded and that there was a lack of research evidence to support therapies based on it. They cited early studies indicating that reading problems were primarily the result of difficulties with language processes, an observation that has since been strongly supported by both behavioral and brain imaging research (e.g., Shaywitz, 2003). Based on the perceptual deficit hypothesis and theories relating dyslexia to inadequately developed hemispheric dominance, an approach known as perceptual-motor training was popularized. Perceptual-motor therapies might include activities such as walking on balance beams and throwing bean bags. A meta-analysis (i.e., a statistical summary of several studies on a given topic) of studies on perceptual-motor training found that this training had no effect on reading outcomes (Kavale & Mattson, 1983). Although the early theories described here have been disproven, Hyatt (2007) suggested that the intervention Brain Gym is based on all three. Hyatt observed that Brain Gym was being marketed in more than 80 countries at the time his article was written. He located five studies evaluating the program. In one, the author of the research report was one of the four study subjects, so it was not reviewed. The other four papers, according to Hyatt, were published in a journal in which authors pay for publication. He cited serious flaws in all four studies, concluding that there is a lack of scientific evidence supporting the program. The Cerebellar Theory of Dyslexia More recently, a group of researchers has proposed the cerebellar theory of dyslexia, or cerebellar dysfunction hypothesis, and exercise programs based on this theory have been promoted as interventions for children with ADHD and dyslexia. The cerebellum, located toward the back of the brain underneath the large cerebral hemispheres, has an important role in coordinating movement. People with cerebellar damage typically have problems with balance, posture, and coordination. The cerebellum also has a smaller role in attention and some kinds of learning. The cerebellar dysfunction hypothesis suggests that the cerebellum is active during the initial stages of learning a skill, but once a skill becomes more automatic, the cerebellum plays a reduced role (Nicolson & Fawcett, 1990). Proponents of this theory hypothesize that an underlying cause of problems associated with dyslexia is impaired cerebellar functioning, which they suggest slows the process of developing fluency (i.e., automaticity) in word reading (Nicolson & Fawcett, 2007). Phonological awareness, a basis for phonological decoding (i.e., using letter-sound correspondences), may be based on learning that is affected in part by the cerebellum. Thus, it has been theorized that cerebellar impairments limit the ability of some students to benefit from typical reading instruction (Nicolson & Fawcett, 2007). This theory is considered plausible by some, but it has not been proven, and there are other explanations of phonological problems in children with dyslexia that have more research support (D. V. M. Bishop, 2007; Fletcher et al., 2007). Cerebellar-Based Exercise Programs Based on the cerebellar dysfunction theory, some have suggested that participating in a set of repeated exercise drills stimulates the cerebellum and remediates cerebellar deficits, thereby improving children's reading performance. Proponents state that engaging in cerebellar exercises over a period of months enables students with dyslexia to respond quickly to reading instruction. The most prominent commercially available cerebellar exercise program is the Dore program, which consists of a daily routine of prescribed exercises performed at home with parental support for up to 12 months. The exercise routines are individually designed and change over time based on ongoing assessment of domains, such as balance, thought to be indicative of cerebellar functioning. Dore program materials suggest that engaging in these exercises in two 10-minute sessions per day can remediate dyslexic symptoms (Dore USA, 2010). Research on Cerebellar Exercise Programs The Dore program has never received an independent evaluation using a high quality experimental design. Two published studies have evaluated the effects of another cerebellar exercise treatment, the Dyslexia Dyspraxia Attention Treatment (DDAT) program (Reynolds & Nicolson, 2007; Reynolds et al., 2003), but both were conducted by proponents of the cerebellar dysfunction theory. Although these studies were not conducted with the current Dore program, they are cited on Dore websites as the primary research support for the program. Participants in Reynolds et al. (2003) and Reynolds and Nicolson (2007) were identified as at-risk for literacy difficulties based on the Dyslexia Screening Test (DST) (Fawcett & Nicolson, 2004), and the DST was also the primary tool used to evaluate the effects of the intervention. The Dyslexia Screening Test. The DST includes subtests that measure word reading, reading text passages with nonsense words inserted, spelling, and writing. Other DST subtests measure cognitive and language skills, and two of the subtests, Bead Threading (number of wooden beads threaded on a cord in 30 seconds) and Postural Stability, or balance, are designed to measure processes regulated by the cerebellum. In the test manual, Fawcett and Nicolson (2004) stated that the postural stability subtest is "the test that has been shown to be one of the best predictors of resistance to [reading] remediation" (p. 15). This statement was not supported by a study in which Barth and colleagues (2010) found that groups of children at-risk for serious reading difficulties who demonstrated strong and weak responses to a first grade supplemental reading intervention performed differently on measures of phonological awareness, rapid naming, and vocabulary; however, the high and low responders did not differ from each other on DST Bead Threading or Postural Stability. Studies of cerebellar exercise. The first study of a cerebellar exercise treatment was a randomized study of the DDAT program conducted with 36 children in one school in England (Reynolds et al., 2003), and the second paper was a follow-up with the children from this study who remained at the school a year later (Reynolds & Nicolson, 2007). The following description of the studies is illustrated in Figure 1. The 36 participants, ages 7 to 10 years, were identified as at-risk for literacy difficulties using the DST composite score (an average across all the DST subtests, including both reading and nonreading measures). Then, they were matched for age and composite DST scores and randomly assigned to receive 6 months of the DDAT cerebellar exercise treatment (Figure 1, Group 1) or to a control group who did not do the exercises (Figure 1, Group 2). Only six of the children (four in Group 1 and two in Group 2) were identified as having dyslexia, and school-administered tests indicated that several children in each group were performing above grade-level expectations in reading at the beginning of the study. For 6 months, Group 1 engaged in cerebellar exercises at home for 5 to 10 minutes twice per day, while Group 2 was not given the exercises during this period. The researchers did not provide information about how regularly the children in Group 1 actually did the exercises or whether they implemented the program as it was described. Some examples of the exercises included standing on a balance board, throwing and catching bean bags while tracking them with the eyes, spinning, and other motor coordination exercises (Reynolds & Nicolson, 2007). After 6 months, both groups were tested again using the DST (Test 2). Reynolds & Nicholson (2007) reported that after the first 6 months, the Group 2 children were also given the exercise therapy (see Figure 1). After 6 months they were retested with the DST (Test 3). Children in both groups received the treatment for about 12 months. Then, 6 to 12 months after completion of the treatment, all of the children were tested again (Test 4). Taken together, the results of the two studies of cerebellar exercise therapy showed that, on the reading subtests of the DST a) at the end of the first 6-month period (Test 2), Group 1 had significantly better DST word reading scores than Group 2 (Reynolds et al., 2003), b) Group 2 showed no immediate effects on DST reading tests after 6 months of the exercise treatment (Test 3; Rack et al., 2007), and c) when the two groups were combined, Test 4 showed that they had not continued to improve on literacy-related DST tests 6 to 12 months later (Reynolds & Nicolson, 2007). This finding does not support the central premise of cerebellar exercise treatments–that engaging in the cerebellar exercises would prepare the brain to benefit from reading instruction provided after the cerebellar problems had been corrected, since the only improvement on the DST reading measures was during the 6-month period during which the first cohort of children were engaged in the exercises. During the period between Test 2 and Test 4, when you might expect to see the most improvement based on the theory that cerebellar exercises prepare the brain to learn to read, the only DST test that showed significant improvement was Postural Stability. The children's average DST scores for word reading, spelling, and nonsense passage reading remained essentially unchanged between Test 2 and Test 4, with trivial gains in spelling and trivial losses in reading (Reynolds & Nicolson, 2007). The researchers also reported that Group 1 had greater growth on school-administered tests during the school year in which they had the exercise treatment than the same group had demonstrated during the previous school year, but it is impossible to determine whether this improved growth was because of the exercise program or for some other reason (e.g., an expert teacher or changes in reading instruction) because the authors did not report the amount of growth made by the control group (Group 2) on these measures during the same period. The same problem exists in interpreting long-term gains in school-administered reading tests reported by Reynolds and Nicholson (2007). There is no way to know whether these gains were due to the exercise treatment. Both of these studies were severely criticized by several researchers and dyslexia experts, who suggested that the way the DST was used and the methods used to analyze the data and report the results resulted in bias toward the exercise program (Bishop, 2007; 2008; Rack et al., 2007; Richards et al., 2003; Singleton & Stuart, 2003; Snowling & Hulme, 2003; Stein, 2003; Whiteley & Pope, 2003). Although several of the commentaries suggested that it is reasonable to evaluate innovative interventions for dyslexia, they all agreed that the studies by Reynolds and colleagues were seriously flawed. Some of the criticisms of the study were that matching students on the DST composite score (including both reading and non-reading subtests) before randomly assigning them to Group 1 or 2 resulted in differences in the reading abilities of children in the two groups at the beginning of the study that could have had an impact on the outcomes. For example, because several children were not actually at-risk for reading difficulties at the beginning of the study, they would be expected to improve on reading tests with quality classroom instruction alone. Thus, gains seen for Group 1 after the first 6 months may not have been related to the exercise treatment. Some critics have also suggested that Group 1 may have improved because of the added attention they received from their parents or simply due to doing exercises of any kind, since physical exercise has been associated with improved attitudes and attention. Following the publication of the follow-up study, Rack et al. (2007) noted that Reynolds and Nicholson had failed to report the results of Test 3, when immediate effects for Group 2 could be evaluated. Rack and colleagues later obtained these results from Reynolds and Nicholson, revealing that participation in the DDAT exercise program had no immediate effects on reading scores for this second cohort. Transfer to untrained skills. In general, the lesson from decades of research on various kinds of training studies is that it is relatively easy to improve skills that are actually trained, but it is much harder to improve skills in a different domain that is not directly trained. This issue, known as the transfer problem, appears to be relevant to the cerebellar exercise treatments researched by Reynolds and colleagues, since sustained growth was seen on the DST measures of posture and dexterity (which were directly trained through the exercises), but not on the reading measures. Summary: Potential Benefits and Risks of Movement- Based Therapies This article began with the suggestion that the potential benefits and risks of any treatment or intervention should be weighed before making treatment decisions. Regardless of the final decision, it should be informed by objective information rather than testimonials and Internet advertising. For educators and clinicians, the need to base decisions on solid research evidence is even more critical, as these professionals have responsibility for many children, and their decisions may have lifelong consequences. Benefits. There is currently insufficient evidence that exercise or movement-based therapies are effective in remediating dyslexia. Early theories of brain disorganization, lack of hemispheric dominance, and perceptual-motor deficits have been discredited, and therapies based on these theories lack scientific evidence to support them. In fact, in some cases, good evidence suggests the opposite–that these treatments are not effective. The current studies of cerebellar exercise therapy do not provide evidence that children would be likely to benefit from participating in a course of cerebellar exercises as a treatment for dyslexia; however, they do not conclusively show that this intervention does not work. As Nicolson and Reynolds (2003) themselves noted, the issues that have been raised about these evaluations should be addressed through a carefully designed, large-scale, independent investigation, but to date, no study of this kind has been conducted. Risks. It seems unlikely that a child would be physically injured by participating in the exercises described in this article, but a doctor's exam would certainly be in order before starting any exercise regimen. In fact, general physical exercise contributes to physical and emotional health and has been associated with improved mental functioning and attention. However, it is entirely possible that children with dyslexia, and their families, could be harmed emotionally if they engage in a year-long therapy program with high expectations, only to find that there are few effects on the child's reading. Unwarranted expectations of a "cure" for a child's dyslexia, along with financial strain of investing in expensive programs, could result in substantial stress for both children and their families. Serious harm could also be caused by delaying potentially more effective interventions as children with dyslexia engage in months of ineffective treatment, since children with impaired reading become farther and farther behind their peers as time passes, not only in their reading skills but also in their vocabulary knowledge and general world knowledge. They may also suffer the serious emotional consequences of repeated failure. Therefore, it seems prudent to carefully evaluate any treatment program and to select those with the most likelihood of success. Options. A growing number of neuroimaging studies have revealed that intensive instruction with certain characteristics can result in substantial changes in brain functioning for children with severe reading difficulties (e.g., Simos et al., 2002; 2007). Vellutino et al. (1977) concluded their article on perceptual deficit training approaches with suggestions that are as relevant today as they were in the 1970s. They proposed that assessment and treatment for reading disabilities should a) focus on tasks that are the most similar to the skills the children need to learn, b) provide direct instruction rather than asking children to learn by inferring what they need to know, c) determine and build upon a student's strengths, d) avoid assumptions that a student is unable to learn skills based on unsupported theories or even previous unsuccessful attempts to teach the skills, and e) develop individualized programs. The accumulation of scientific evidence suggests that children would be more likely to benefit from receiving intensive reading instruction to address phonologically-based reading difficulties directly than from exercise therapies. It seems reasonable to suggest that children would also benefit from a general program of daily exercise and from reading daily with their parents in a non-threatening, supportive atmosphere, activities that do not require investment in expensive programs that lack adequate evidence to support their claims. References American Academy of Pediatrics. (1982). The Doman-Delacato treatment of neurologically handicapped children. Pediatrics, 70(5), 810–812. American Academy of Pediatrics. (1999). The treatment of neurologically impaired children using patterning. Pediatrics, 104(5), 1149–1151. Barth, A. E., Denton, C. A., Stuebing, K. K., Fletcher, J. M., Cirino, P. T., Francis, D. J., et al. (2010). 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Follow-up of an exercise-based treatment for children with reading difficulties. Dyslexia, 13(2), 78–96. doi:10.1002/dys.331 Reynolds, D., Nicolson, R. I., & Hambly, H. (2003). Evaluation of an exercise-based treatment for children with reading difficulties. Dyslexia, 9(1), 48–71; discussion 46–47. doi:10.1002/dys.235 Richards, I. L., Moores, E., Witton, C., Reddy, P. A., Rippon, G., Rochelle, K. S. H., & Talcott, J. B. (2003). Science, sophistry and 'commercial sensitivity': Comments on 'evaluation of an exercise-based treatment for children with reading difficulties', by Reynolds, Nicolson and Hambly. Dyslexia, 9, 146–150. doi:10.1002/dys.258 Shaywitz, S. (2003). Overcoming dyslexia: A new and complete science-based program for reading problems at any level. New York: Knopf. Simos, P. G., Fletcher, J. M., Bergman, E., Breier, J. I., Foorman, B. R., Castillo, E. M., et al. (2002). Dyslexia-specific brain activation profile becomes normal following successful remedial training. Neurology, 58, 1–10. Simos, P. G., Fletcher, J. M., Sarkari, S., Billingsley-Marshall, R., Denton, C. A., Papanicolaou, A. C. (2007). Intensive instruction affects brain magnetic activity associated with oral word reading in children with persistent reading difficulties. Journal of Learning Disabilities, 40(1), 37–48. Singleton, C., & Stuart, M. (2003). Measurement mischief: A critique of Reynolds, Nicolson and Hambly (2003). Dyslexia, 9(3), 151–160; discussion 167–176. doi:10.1002/dys.256 Snowling, M. J., & Hulme, C. (2003). A critique of claims from Reynolds, Nicolson & Hambly (2003) that DDAT is an effective treatment for children with reading difficulties–'Lies, damned lies and (inappropriate) statistics'? Dyslexia, 9(2), 127– 133; discussion 134–125. doi:10.1002/dys.245 Stein, J. (2003). Evaluation of an exercise based treatment for children with reading difficulties. Dyslexia, 9(2), 124–126. doi:10.1002/dys.247 Tomporowski, P. D., Davis, C. L., Miller, P. H., & Naglieri, J. A. (2008). Exercise and children's intelligence, cognition, and academic achievement. Educational Psychology Review, 20(2), 111–131. Vellutino, F. R., Steger, B. M., Harding, C. J., Niles, J. A., & Moyer, S. C. (1977). Has the perceptual deficit hypothesis led us astray? Journal of Learning Disabilities, 10(6), 375–385. Whiteley, H. E., & Pope, D. (2003). Evaluation of an exercise-based treatment for children with reading difficulties. Dyslexia, 9(3), 164–166; discussion 167–176. doi:10.1002/dys.257 Carolyn Denton, Ph.D., is an associate professor in the Children's Learning Institute, located in the Department of Pediatrics at the University of Texas Health Science Center at Houston. Her research investigates reading difficulties and disabilities, the effects of reading interventions, treatments for children who have both attention and reading difficulties, the use of Response to Intervention models in the identification of learning disabilities, adolescent reading comprehension, and coaching as a form of professional development. Dr. Denton is the author of a first grade reading intervention program, Responsive Reading Instruction, published by Sopris West/Voyager.
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