Perlunya penelitian longitudinal untuk memahami disleksia pada anak-anak; jangan berpikir instan terus

Ini adalah abstrak yang lain yang presentasinya saya dengarkan pada konferensi penutupan Dutch Dyslexia Program (Amsterdam, 8 Desember 2011). Semoga abstrak ini menggugah kita untuk menyadari pentingnya penelitian secara longitudinal untuk memahami inti masalah dari disleksia pada anak-anak. Penelitian memang tidak pernah instan tapi ilmu yang diberikannya akan dapat memperbaiki kehidupan kita semua.

Prof. dr. Paavo H.T. Leppanen, University of Jyvaskyla, Finland

(huruf-huruf dengan umlaut tidak dapat saya munculkan di sini karena keterbatasan font di multiply)

Aberrant auditory and speech processing linked with familial dyslexia-- a longitudinal follow-up of brain responses

The role of various risk factors for dyslexia, developmental reading disorder, has been debated for several decades. Phonological processing problems are widely acknowledged as a major deficit for dyslexia. However, relatively little is known of underlying neurocognitive risk factors and their interaction with later reading problems and related cognitive skills. Here we review brain response (event-related potential, ERP) findings from the Jyvaskyla Longitudinal Study of Dyslexia (JLD). We have been especially interested in whether dyslexic children with familial risk background would show atypical auditory/speech processing already at infancy and whether these deficits persist in development and how the brain responses measured before reading age would be related to later pre-reading cognitive skills and literacy outcome. One half of the children came from families with at least one dyslexic parent (the at-risk group), while the other half belonged to the control group without any familial background of dyslexia. The early ERPs were correlated to pre-school age phonological processing and letter-naming skills as well as phoneme duration perception, reading and writing skills at 2nd grade at 9 years. The correlations were, in general, more consistent among at-risk children. Developmental changes were observed in these associations. Those at-risk children who became poor readers also differed from typical readers in the infant ERP measures at the group level. ERPs measured at the pre-school age and 3rd grade also differed between dyslexic and typical readers. Further, speech perception at behavioral level differed between dyslexic and typical readers at school-age, but not in all dyslexic readers. The findings suggest persisting developmental differences in the organization of the neural networks sub-serving auditory/speech perception with cascading effects on later reading related skills in children with familial background for dyslexia. However, atypical auditory/speech processing is not likely a sufficient reason by itself for dyslexia but rather one endophenotype/risk factor. Challenges remain, therefore, for the individual identification of high risk children.