Neuropsychologia, 0 Pergamon Press
Vol. Ltd.
16, pp. 483 to 489. 1978. Printed in Great
Britain.
THE INFLUENCE OF DIFFERENTIAL AUDITORY FEEDBACK UPON THE READING OF DYSLEXIC CHILDREN JOHN STUART GILLIS* and AGATHA E. SIDLAUSKAS Child Study Centre, University of Ottawa, Canada (Received 11 January 1977) Abstract-With the aim of investigating the possibility of a relationship between ear laterality and reading performance, ten dyslexic children were studied under different conditions of auditory feedback. It was found that oral reading was more rapid when feedback was directed mainly to the right ear instead of at equal intensity to both ears. The possible effect of amplifying high frequencies and attenuating low frequencies was also studied, but the results were not as clear. Consideration was given to theoretical interpretation similar to that which has been proposed for the well established right ear advantage in normals.
INTRODUCTION IN RECENT years a considerable body of literature has accumulated which indicates that linguistic stimuli (consonants, words, digits, syllables) are reported more rapidly and accurately when presented to the right ear [l-28], while nonlinguistic stimuli (melodies, environmental sounds) are processed more effectively when directed to the left ear [29-331. Influenced by the well-known proposals of a connection between cerebral dominance, inferred from sensory and/or motor asymmetry, and specific reading disability (ORTON [34] and ZANGWILL [35]), studies have also been carried out with the aim of investigating the possibility of a relationship between ear laterality and reading performance [36-41]. In reviewing this research, SATZ [42] has concluded that such a hypothesis “is only partially supported by the data�. The present study was undertaken with the goal of providing additional information about the question of ear laterality and reading by taking a somewhat different approach from past research. In previous work children have typically been classified into groups of good or normal readers who are then compared with poor or disabled readers with respect to the degree of ear asymmetry shown in dichotic or monaural listening tasks. The prediction has been that disabled readers, being less well lateralized, would show less right ear superiority than the normal readers. An alternative approach, suggested by the work of TOMATIS [43-461, would be to compare the ordinary reading behavior of dyslexic children with that which they produce when forced to listen with the right ear. The expectation would be that the children would read better when artificially lateralized. Since it has been suggested that the frequency of auditory information may be importantly involved in ear lateralization (SPELLACY and BLUMSTEIN [47]) and reading attainment (HENRY [48] and TOMATIS [43, 44]), it was also decided to investigate the possibility of frequency modification effects upon reading performance. *Present address: Canada E3B 5G3.
Department
of Psychology,
St. Thomas
483
University,
Fredericton,
New Brunswick,