The early identification of dyslexia.

The objective of this study was to develop a screening test to identify children at risk
for dyslexia at four or five years of age. A battery of tests, based on recent theoretical
developments in dyslexia research, and including measures such as tests of IQ,
phonological and motor skills, and reaction time, was administered to 91 children
(including a small group with dyslexic parents or siblings) at the age of four and five
years. Subjects were followed up at 6.6 and 7 years, and a group of dyslexic children
were identified. Following analysis of differences in the performance of dyslexic and
non-dyslexic subjects, a number of measures of phonological skills, fine motor skills
and memory were combined to form the Screening Predictive Index (SPI). It was found
that early identification of dyslexia was possible at moderate levels, however
limitations in the selection of outcome groups may have reduced accuracy of prediction.
In addition, slow learners were found to have performed similarly to the dyslexics on
the SPI and therefore, to increase tile accuracy of prediction, a further set of tests were
combined into an annex to tile SPI - the Screening Predictive Index (II). Background
information was also studied. Theoretical issues concerning the early manifestations of
dyslexia and the relationship of dyslexia to other forms of poor reading were examined.
The findings of tile study supported the existence of deficits in phonological skills in
young children with dyslexia, and also difficulties with fine motor skills. However, no
clear support for any of the existing theories of dyslexia was found. Further evidence
of measures that distinguish dyslexics from slow learners, such as tests of cerebellar
function, may be required for the accurate early identification of dyslexia.