Theory and intervention : a complete analysis for children with learning difficulties.

The two main aims of the research presented in this thesis are firstly; to develop
theoretically valid methods of distinguishing between dyslexic and non dyslexic
poor readers (ND-PR) through the use of behavioural tests in a range of primitive
skill areas and secondly; to develop and evaluate three intervention programmes
for learning disabled children based on sound theoretical principles. The
implications of these findings for the traditional discrepancy definition of
dyslexia are considered.
In the first set of studies, dyslexic and ND-PR were tested at 8 and 10 years of
age on a battery of theoretically chosen tests of primitive skills. As expected
from the literature, both the dyslexic and ND-PR showed difficulties in
phonological skills (Bradley and Bryant, 1983; Snowling et al., 1986; Vellutino,
1979). However, by contrast the dyslexic children also showed difficulties in
certain tests of cerebellar dysfunction, whereas the ND-PR did not. This
dissociation presents evidence for the cerebellar impairment hypothesis
(Nicolson, Fawcett and Dean 1995). Findings give early support for the
supposition that the phonological deficit theory may be subsumed within a
broader causal framework of cerebellar impairment. Findings also suggest that
there is value in retaining the discrepancy definition of dyslexia.
The second set of studies compared three types of training on skill acquisition for
children of varied ability ages 5 to 6 years. The groups were given systematic
training over a period of several weeks using a phonological, motor and
arithmetic skill programme. Training was designed for administration by a
relatively unskilled instructor. Parents successfully delivered the first training
programme, the author the second. Promising results were reported for both
small-scale studies. Persistent performance improvement in all training groups
were shown in measures of reading and spelling age and IQ, together with
cautious evidence of skill transfer. Interpretation of the results suggests that each
of the training programmes had generic value for metacognition. The findings
provide a demonstration of both the effectiveness and cost-effectiveness of this
type of structured and regular training intervention with young children,
particularly those with learning difficulties. Implications for both the
phonological and cerebellar impairment hypotheses are discussed. It is proposed
that a motor skill training programme in conjunction with a phonological training
programme has potential in any home/school based intervention.