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ACQ
Volume 11, Number 2 2009
ACQ
uiring knowledge in speech, language and hearing
At Macquarie Centre for Cognitive Science
(MACCS), we have an ongoing program of research which
focuses on using a cognitive neuropsychological approach
to understand and treat of disorders of reading and spelling.
Here we summarise three recent areas of research. However,
other active research projects include the development and
norming of spelling tests for the differential diagnosis of
spelling difficulties (Kohnen, Nickels & Castles, 2009).
Orthographic learning for new
written words
Past research has shown that the ability to store written words
in a mental word store (i.e., orthographic learning) is impaired
in developmental reading and spelling problems (dyslexia/
dysgraphia; DiBetta & Romani, 2006). Hence, children and
adults with spelling and reading problems are slower at
learning spellings of new words. We have found that
treatment can improve the reading/spelling of trained
Cognitive neuropsychology is a branch of cognitive
psychology. It has two major components:
1 To use data from cognitive impairments to further our
understanding of normal cognitive processes (e.g., the
problems individuals have in reading or spelling can be
used to evaluate theories of reading and spelling).
2 To use theories of cognitive function to help us
understand better the impairments of those with
cognitive impairments (e.g., use theories of reading to
determine which components of the reading process
are impaired and which intact for a particular individual
with dyslexia).
The cognitive neuropsychological approach
to
assessment
involves systematic, hypothesis-driven
assessment of the component processes of a cognitive
task (e.g., reading) to establish which of these processes
are intact and which impaired, i.e., establishing the “level
of impairment” of a particular skill within a cognitive
model. The basis of this approach is to use the pattern of
success and failure across tasks (e.g., reading of irregular
words versus reading of non-words) to draw conclusions
as to which processing routines are available and which
are impaired.
The cognitive neuropsychological approach
to
treatment
rests on the assumption that treatment will be
maximally effective only when the direction of treatment
is determined by precise knowledge of the individual’s
language processing strengths and weaknesses. Hence,
Understanding and treating develop
mental literacy impairments using a
cognitive neuropsychological approach
Macquarie Centre for Cognitive Science
Lyndsey Nickels, Saskia Kohnen, and Karen Smith-Lock
Research updates
as symptoms (e.g., poor word reading) can arise as
a result of various different types of impairment (e.g.,
problems with rule knowledge, problems with sight word
knowledge), analysis limited to surface symptoms will not
enable construction of effective treatments. The cognitive
neuropsychological approach to treatment also has a
strong commitment to methodological rigour in evaluation
of the effects of treatment, using single case study
experimental designs.
Detailed assessment based on a cognitive theory
thus enables treatment to be directed precisely at the
problems that have been identified and to capitalise
on those processing abilities that remain (relatively)
unimpaired. Similarly, the effects of treatment on the
impairments can be precisely monitored with retesting.
Analysis of what is wrong however unfortunately doesn’t
uniquely determine what to do about it, but does narrow
down the options (e.g., if an individual with poor reading
was found to have good knowledge of letter–sound
rules, a phonics program would not be an appropriate
treatment approach).
Further reading
Ellis, A.W., and Young, A.W. (1996).
Human cognitive
neuropsychology: A textbook with readings
. Hove, East
Sussex: Lawrence Erlbaum. (an introductory textbook)
Jackson, N.E. and Coltheart, M. (2001)
Routes to
reading success and failure
. Hove: Psychology Press.
What is cognitive neuropsychology?
irregular words (words where their spelling/pronunciation has
to be learned and cannot be derived by rule, e.g.,
yacht
).
Interestingly, misspelled words which are not trained also
show improved reading/spelling (e.g., Brunsdon, Coltheart &
Nickels, 2005; Kohnen, Nickels, Coltheart & Brunsdon,
2008). Why does this improvement happen?
One possibility for explaining this improvement is that
remediation may have had beneficial effects on orthographic
learning, in other words, on the process of actually acquiring
orthographic representations. We are investigating this
possibility by looking at how orthographic learning might
change over the course of an intervention for children
with different subtypes of literacy disorders. In order to do
this, orthographic learning tasks are administered to the
participants before and after training. Typically, orthographic
learning tasks consist of stories in which a new word is
introduced (e.g., “In the olden days people used to eat a
dish called
stromp
. Stromp tastes like rice…”). Orthographic