Notes that high-resolution magnetic resonance imaging allows in vivo quantification of the surface area of the cortex covering the planum temporale. Reviews the definition of planum asymmetry as it relates to structural accompaniments of disorders such as developmental dyslexia and to anatomic and functional lateralization. Finds support for the…

Dyslexia appears to be a meaningless label attached to children with reading problems; the label only leads to confusion rather than clarity. (JH)

Examined with 38 right-handed boys who were either dyslexic or normal readers and matched for age and IQ (mean age both groups=10.6, mean IQ normal readers=106, mean IQ dyslexic readers=105) were the weak, strong, and equal lateralization theories of dyslexia. Cerebral lateralization was measured for linguistic material (digits) using the dichotic…

Evaluates a substantially updated version of the "classical" idea of a significant relationship in dyslexic children between cerebral lateralization and their word decoding deficits. Finds further evidence that dyslexia is not related to incomplete lateralization. Suggests that dyslexics suffer from exuberant right hemisphere processing in…

Investigates visual processing asymmetries in normal and dyslexic readers to determine whether differences between dyslexics and normals were due to structural hemispherical differences or to strategical processing differences. Results indicate dyslexics behave as normal readers if they are unable to predict whether the stimulus will be verbal or…

A study investigated whether a correlation exists between the degree and nature of left-brain laterality and specific reading and spelling difficulties. Subjects, 50 normal readers and 50 reading disabled persons native to the island of Bornholm, had their auditory laterality screened using pure-tone audiometry and dichotic listening. Results…

This is a final report of research in dichotic listening performance (DLP). The purposes for the research were to study the development of DLP in children and adults, to examine DLP as a function of verbal information presented in a task, to determine the contribution of perceptual and mnemonic factors affecting DLP by controlling order-of-report…

Discusses some current concepts of the laterality/reading relationship. An overview of Samuel T. Orton's hypotheses of cerebral dominance and "strephosymbolia" is provided, and both visual half-field and dichotic listening studies as direct, empirical tests of laterality are discussed. (MKM)