A Closer Look at Motor Overflow in Dyslexic

Unintentional movement "overflow" between the hands or "mirror movements" are common in young children, but are generally regarded as indicative of developmental delay in older children. This study was designed to investigate mirror movements in a sample of 23 very poor readers, ages 11-13, with learning disabilities, and in a control group of 48 normal readers, matched for age, sex, and handedness. Five rapid repetitive movements and eight slow finger-displacement movements were studied, and overflow to the opposite hand was quantified. A significant interaction of reading ability with type of movement was observed, with reading-impaired children making more mirror movements during slow finger displacements (but not during rapid repetitive movements) than normal readers. Reading-impaired children showed greater left-hand overflow and normal control children showed greater right-hand overflow overall. The two groups were differentiated by the pattern of overflow rather than the overall amount. It is concluded that dyslexic children were more likely than normal children to co-activate the left hemisphere whenever the left hand was used, and dyslexic children activated both hemispheres in circumstances where normal children did not. (Includes seven references.) (JDD) *********************************************************************** * Reproductions supplied by EDRS are the best that can be made * * from the original document. * *********************************************************************** 'PERMISSION TO REPRODUCE THIS MATERIAL HAS BEEN GRAITED BY , A:z TO THE EDUCATIONAL RESOURCES INFORMATION CENTER (ERIC).' U.S. DEPARTMENT OF EDUCATION Office of Educational Research and Improvement EDUCATIONAL RESOURCES INFORMATION CENTER (ERIC) Dergs document has been reproduced s received from the person or organization origmOngn fl Minor changes have peen made to improve reproduction Quality Points of view nr cpsniona slated in this document do not necessarily represent official OERI Position or policy A Closer Look at Motor Overflow in Dyslexic Children* S.E. Parlow, Dept. of Psychology, Carleton University, Ottawa ABsTRACT The effects of type of movement and reading ability on "mirror movements" were examined in 2? ..;ar-fully selected poor-readers between 11 and 13 years of age, and in a control sample of 48 normal-readers, matched for age, sex and handedness. These poorreaders had very poor word-recognition skills (Wrat-R reading, M=3 %ile) despite normal intelligence and adequate educational opportunities. A significant interaction of reading ability x type of movement was observed, with reading-impaired children making more mi.rror movements during slow finger-displacements (but not during rapid repetitive movements) than normal-readers. The interaction of reading ability x hand was also significant. Reading-impaired children showed greater left-hand overflow and normal control children greater right-hand overflow overall. Implications for brain organization in dyslexia are discussed.The effects of type of movement and reading ability on "mirror movements" were examined in 2? ..;ar-fully selected poor-readers between 11 and 13 years of age, and in a control sample of 48 normal-readers, matched for age, sex and handedness. These poorreaders had very poor word-recognition skills (Wrat-R reading, M=3 %ile) despite normal intelligence and adequate educational opportunities. A significant interaction of reading ability x type of movement was observed, with reading-impaired children making more mi.rror movements during slow finger-displacements (but not during rapid repetitive movements) than normal-readers. The interaction of reading ability x hand was also significant. Reading-impaired children showed greater left-hand overflow and normal control children greater right-hand overflow overall. Implications for brain organization in dyslexia are discussed.