Minna Torppa

Language development, literacy skills and predictive connections to reading in Finnish children with and without familial risk for dyslexia

Discriminative language markers and predictive links between early language and literacy skills were investigated retrospectively in the Jyväskylä Longitudinal Study of Dyslexia in which children at familial risk for dyslexia have been followed from birth. Three groups were formed on the basis of 198 children’s reading and spelling status. One group of children with reading disability (RD; n = 46) and two groups of typical readers from nondyslexic control (TRC; n = 84) and dyslexic families (TRD; n = 68) were examined from age 1.5 years to school age. The RD group was outperformed by typical readers on numerous language and literacy measures (expressive and receptive language, morphology, phonological sensitivity, RAN, and letter knowledge) from 2 years of age onward. The strongest predictive links emerged from receptive and expressive language to reading via measures of letter naming, rapid naming, morphology, and phonological awareness.

Predicting delayed letter knowledge development and its relation to grade 1 reading achievement among children with and without familial risk for dyslexia.

The authors examined the developmental trajectories of childrens early letter knowledge in relation to measures spanning and encompassing their prior language-related and cognitive measures and environmental factors and their subsequent Grade 1 reading achievement. Letter knowledge was assessed longitudinally at ages 4.5, 5.0, 5.5, and 6.5 years; earlier language skills and environmental factors were assessed at ages 3.5 and 4.5 years; and reading achievement was assessed at the beginning and end of Grade 1. The analyses were conducted on a longitudinal data set involving children with and without familial risk for dyslexia. Emerging from the trajectory analysis of letter knowledge were 3 separate clusters: delayed (n = 63), linearly growing (n = 73), and precocious (n = 51). The members of the delayed cluster were predominantly children with familial risk for dyslexia, and the members of the precocious cluster were predominantly control group children. Phonological sensitivity, phonological memory, and rapid naming skills predicted delayed letter knowledge. Environmental predictors included level of maternal education and the amount of letter name teaching. Familial risk for dyslexia made a significant contribution to the predictive relations. Membership in the delayed cluster predicted poor reading performance at Grade 1.

Developmental Links of Very Early Phonological and Language Skills to Second Grade Reading Outcomes: Strong to Accuracy but Only Minor to Fluency

The authors examined second grade reading accuracy and fluency and their associations via letter knowledge to phonological and language predictors assessed at 3.5, 4.5, and 5.5 years in children in the Jyväskylä Longitudinal Study of Dyslexia. Structural equation modeling showed that a developmentally highly stable factor (early phonological and language processing [EPLP]) behind key dyslexia predictors (i.e., phonological awareness, short-term memory, rapid naming, vocabulary, and pseudoword repetition) could already be identified at 3.5 years. EPLP was significantly associated with reading and spelling accuracy and by age with letter knowledge. However, EPLP had only a minor link with reading fluency, which was additionally explained by early letter knowledge. The results show that reading accuracy is well predicted by early phonological and language skills. Variation in fluent reading skills is not well explained by early skills, suggesting factors other than phonological core skills. Future research is suggested to explore the factors behind the development of fast and accurate decoding skills.

Modeling the Early Paths of Phonological Awareness and Factors Supporting its Development in Children With and Without Familial Risk of Dyslexia

The development of phonological awareness (PA) before school age was modeled in association with the development of vocabulary and letter knowledge, home literacy environment (HLE), childrens reading interest, and beginning reading skill in children with and without familial risk of dyslexia. A total of 186 children were followed from birth to the age of 6.5 years. Of these children, about half had a familial background of reading difficulties (the at-risk group), and the other half came from families without such background (the control group). The data from several measures and assessment time points were analyzed within an SEM framework, and a latent analysis of growth curves was employed. Vocabulary and letter knowledge were found to predict PA development, and vice versa, PA predicted them. The effect of HLE on PA was mediated by vocabulary skills, and of the HLE variables, the only variable predicting vocabulary development was shared reading. In spite of the difference in level, favoring the controls, the pattern of effects of vocabulary and letter knowledge on PA development was highly similar in children with and without familial risk for dyslexia. However, in the at-risk group, the HLE variables and childrens reading interest had stronger associations with each other and with skill development than in the control group, and vocabulary predicted parental reports on childrens reading interest in the at-risk group only.

Detection of Sound Rise Time by Adults with Dyslexia.

Low sensitivity to amplitude modulated (AM) sounds is reported to be associated with dyslexia. An important aspect of amplitude modulation cycles are the rise and fall times within the sound. In this study, simplified stimuli equivalent to just one cycle were used and sensitivity to varying rise times was explored. Adult participants with dyslexia or compensated dyslexia and a control group performed a detection task with sound pairs of different rise times. Results showed that the participants with dyslexia differed from the control group in rise time detection and a correlation was found between rise time detection and reading and phonological skills. A subgroup of participants with lower sensitivity to rise time detection characterized by low accuracy in syllable-level phonological skills was found within the dyslexic group. Short stimuli containing only one rise time produced associations with phonological skills and reading, even in a language where the perception of rise time contrasts are not crucial for the signaling of phonemic contrast.

Infant brain responses associated with reading-related skills before school and at school age

INTRODUCTION In Jyväskylä Longitudinal Study of Dyslexia, we have investigated neurocognitive processes related to phonology and other risk factors of later reading problems. Here we review studies in which we have investigated whether dyslexic children with familial risk background would show atypical auditory/speech processing at birth, at six months and later before school and at school age as measured by brain event-related potentials (ERPs), and how infant ERPs are related to later pre-reading cognitive skills and literacy outcome. PATIENTS AND METHODS 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. RESULTS Early ERPs were correlated to kindergarten age phonological processing and letter-naming skills as well as phoneme duration perception, reading and writing skills at school age. The correlations were, in general, more consistent among at-risk children. Those at-risk children who became poor readers also differed from typical readers in the infant ERP measures at the group level. ERPs measured before school and at the 3rd grade also differed between dyslexic and typical readers. Further, speech perception at behavioural level differed between dyslexic and typical readers, but not in all dyslexic readers. CONCLUSIONS These findings suggest persisting developmental differences in the organization of the neural networks sub-serving auditory and 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 or risk factor.

Examining the Double-Deficit Hypothesis in an Orthographically Consistent Language.

We examined the double-deficit hypothesis in Finnish. One hundred five Finnish children with high familial risk for dyslexia and 90 children with low family risk were followed from the age of 3½ years until Grade 3. Childrens phonological awareness, rapid naming speed, text reading, and spelling were assessed. A deficit in rapid automatized naming (RAN) predicted slow reading speed across time and spelling difficulties after Grade 1. A deficit in phonological awareness predicted difficulties in spelling, but only in the familial risk sample. The effect of familial risk was significant in the development of phonological awareness, RAN, reading, and spelling. Our findings suggest that the basic premise of the double-deficit hypothesis—that RAN and phonological awareness are separable deficits with different effects on reading and spelling outcomes—holds also in a consistent orthography.

Parental literacy predicts children's literacy: a longitudinal family-risk study.

This family-risk (FR) study examined whether the literacy skills of parents with dyslexia are predictive of the literacy skills of their offspring. We report data from 31 child-parent dyads where both had dyslexia (FR-D) and 68 dyads where the child did not have dyslexia (FR-ND). Findings supported the differences in liability of FR children with and without dyslexia: the parents of the FR-D children had more severe difficulties in pseudoword reading and spelling accuracy, in rapid word recognition, and in text reading fluency than the parents of the FR-ND children. Finally, parental skills were found to be significant predictors of childrens Grade 3 reading and spelling. Parental skills predicted childrens reading and spelling accuracy even after controlling for childrens preschool skills. Our findings suggest that the literacy skills of a parent with dyslexia might be valuable in assessing early on their childs liability to dyslexia.

Predicting Reading Disability: Early Cognitive Risk and Protective Factors

This longitudinal study examined early cognitive risk and protective factors for Grade 2 reading disability (RD). We first examined the reading outcome of 198 children in four developmental cognitive subgroups that were identified in our previous analysis: dysfluent trajectory, declining trajectory, unexpected trajectory and typical trajectory. We found that RD was unevenly distributed among the subgroups, although children with RD were found in all subgroups. A majority of the children with RD had familial risk for dyslexia. Second, we examined in what respect children with similar early cognitive development but different RD outcome differ from each other in cognitive skills, task-focused behaviour and print exposure. The comparison of the groups with high cognitive risk but different RD outcome showed significant differences in phonological skills, in the amount of shared reading and in task-focused behaviour. Children who ended up with RD despite low early cognitive risk had poorer cognitive skills, more task avoidance and they were reading less than children without RD and low cognitive risk. In summary, lack of task avoidance seemed to act as a protective factor, which underlines the importance of keeping children interested in school work and reading.

Dyslexia—Early Identification and Prevention: Highlights from the Jyväskylä Longitudinal Study of Dyslexia

Over two decades of Finnish research, monitoring children born with risk for dyslexia has been carried out in the Jyväskylä Longitudinal Study of Dyslexia (JLD). Two hundred children, half at risk, have been assessed from birth to puberty on hundreds of measures. The aims were to identify measures of prediction of later reading difficulty and to instigate appropriate and earliest diagnosis and intervention. We can identify at-risk children from newborn electroencephalographic brain recordings (Guttorm et al., J Neural Transm 110:1059–1074, 2003). Predictors are also apparent from late-talking infants who have familial background of dyslexia (Lyytinen and Lyytinen, Appl Psycolinguistics 25:397–411, 2004). The earliest easy-to-use predictive measure to identify children who need help to avoid difficulties in learning to read is letter knowledge (Lyytinen et al., Merrill-Palmer Q 52:514–546, 2006). In response, a purpose-engineered computer game, GraphoGame™, provides an effective intervention tool (Lyytinen et al., Scand J Psychol 50:668–675, 2009). In doubling as a research instrument, GraphoGame provides bespoke intervention/reading instruction for typical/atypically developing children. Used extensively throughout Finland, GraphoGame is now crossing the developed and developing world to assist children, irrespective of the cause (environmental or genetic) of their failing to learn to read (Ojanen et al., Front Psychol 6(671):1–13, 2015).