Mikko Aro, Kenneth Eklund, Paavo Leppänen & Anna-Maija Poikkeus

Identification of familial risk and dyslexia in Finnish children

The aim of the Jyväskylä Longitudinal Study of Dyslexia (JLD) was to assess the early signs of dyslexia by following the development of children at risk for reading problemsand control children up to school age. The questions related to assessment of literacy skills and diagnosis of dyslexiawere especially relevant at two stages. The first stage was the inception of the study, when the participants were recruited. The risk group children were selected on the basis of their parents’ reading and spelling problems . The second stage was when the participating children reached school age. At that point diagnostic means and criteria were needed for assessing the outcome of familial risk. This article aims at describing and explaining the decisions made with reference to these diagnostic challenges. The problems related to the assessment of literacy, as well as the diagnostics of dyslexia, are also discussed.

Keywords: dyslexia, assessment of reading skills, identification of dyslexia, diagnostics, reading accuracy, reading speed

Paula Lyytinen

Early language development as the predictor of reading acquisition

Early language development varies widely between individuals. Psychologists who work with children often face situations in which they must judge whether a child’s late talking is an age-associated, transient characteristic or a more persistent delay forecasting later difficulties e.g. in reading acquisition at school age. This article illustrates data from the Jyväskylä Longitudinal study of Dyslexia (JLD) that shows, among children at familial risk for dyslexia, how early language development predicts the need for subsequent support in reading acquisition. Our results demonstrate that the child’s early steps in the production and comprehension of speech items provide important predictive cues about the later development of both spoken and written language skills. Among 2–2.5 year-old children, compromised early language comprehension, together with late onset of talking, predicted more persistent problems in language development and difficulties in reading acquisition than did late-talking alone.

Keywords: late-talking, dyslexia, familial risk, early identification

Pirjo Kulju, Päivi Torvelainen, Ville Pekonen & Matti Leiwo

Early phonological development and dyslexia

In child language as well as in literacy studies word structure is often seen as a linear structure of phonemes/letters. In this article we will present main findings of our linguistic studies which are based on a hierarchical, multilayered word structure. Our studies on early phonological development of children at-risk for dyslexia and their controls support the hypothesis that the possible phonological deficit behind dyslexia is seen in early phonological development. However, individual variation within young children is high which should lead to a careful analysis of individual developmental paths. The studies on early writing skills showed that if a word is seen as a multilayered structure, more information on children’s early writing processes is achieved. For example, in the coding process of long quantity the child may concentrate only on segment level analysis instead of taking into account both the segment level (phoneme quality) and the syllable level (quantity).

Keywords: dyslexia, writing, language development, phonological acquisition

Paavo Leppänen & Jarmo Hämäläinen

Problems in speech perception as a risk factor for dyslexia

Developmental reading problems (dyslexia) are thought to result from interwoven genetic and environmental risk factors. In the Jyväskylä Longitudinal Study of Dyslexia (JLD), we have investigated auditory and speech perception related risk factors from infancy and studied their association to later pre-reading cognitive skills and reading skills. We found that children with familial risk and who later developed dyslexia differed, at the group level, in their brain electrical responses already at birth and later at pre-school and school age from children without reading problems. Brain responses measured at infancy were also associated with later cognitive and reading as well as writing skills. Our results indicate that neural networks sub-serving speech processing and later reading related skills are differently organized in early development in dyslexia. These results further indicate that auditory and speech processing problems are one of the risk factors for dyslexia, which together with other risk factors can increase the probability for dyslexia and make it more difficult, depending on the impact of other risk factors.

Keywords: dyslexia, reading problems, auditory processing, speech perception, risk factor, brain research, event-related potential, ERP

Heikki Lyytinen

Early identification for prevention

The results of the Jyväskylä Longitudinal study of Dyslexia (JLD) reveal that persistent problems in learning to read occur also among readers of fully transparent writing systems, such as Finnish. In order to sound out any word with accuracy, Finnish children must learn grapheme-phoneme connections and become skilled at the assembly of phonemes in the order of letters. Severe problems in the initial acquisition of accuracy and later also of fluent reading skills were observed among 1/4 of children at familial (i.e. genetic) risk for dyslexia. All could be identified in time to facilitate initiation of support before school age. The learning game (Ekapeli), built on the basis of what we have learned in the JLD, demonstrates promising results in terms of preventive intervention. Early empirical results of its adaptation to other orthographies, including English (Graphogame), support this optimism.

Keywords: Familial risk for dyslexia, early identification, prevention