ACQ Vol 11 no 2 2009

Research updates

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

What is cognitive neuropsychology?

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 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, 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

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 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. 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 treatment approach). Further reading

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ACQ Volume 11, Number 2 2009

ACQ uiring knowledge in speech, language and hearing