Neural correlates of statistical learning in developmental dyslexia: An electroencephalography study.

The human brain extracts statistical regularities from the surrounding environment in a process called statistical learning. Behavioural evidence suggests that developmental dyslexia affects statistical learning. However, surprisingly few studies have assessed how developmental dyslexia affects the neural processing underlying this type of learning. We used electroencephalography to explore the neural correlates of an important aspect of statistical learning - sensitivity to transitional probabilities - in individuals with developmental dyslexia. Adults diagnosed with developmental dyslexia (n = 17) and controls (n = 19) were exposed to a continuous stream of sound triplets. Every so often, a triplet ending had a low transitional probability given the triplet's first two sounds ("statistical deviants"). Furthermore, every so often a triplet ending was presented from a deviant location ("acoustic deviants"). We examined mismatch negativity elicited by statistical deviants (sMMN), and MMN elicited by location deviants (i.e., acoustic changes). Acoustic deviants elicited a MMN which was larger in the control group than in the developmental dyslexia group. Statistical deviants elicited a small, yet significant, sMMN in the control group, but not in the developmental dyslexia group. However, the difference between the groups was not significant. Our findings indicate that the neural mechanisms underlying pre-attentive acoustic change detection and implicit statistical auditory learning are both affected in developmental dyslexia.

[Effects of the Computer-Based Grapho-Phonological Training Lautarium in Children with Developmental Dyslexia]. / Wirksamkeit des computergestützten grapho-phonologischen Trainingsprogramms Lautarium bei Kindern mit Lese-Rechtschreib-Störung.

Effects of the Computer-Based Grapho-Phonological Training Lautarium in Children with Developmental Dyslexia The effects of the computer-based training program Lautarium on phonological awareness and literacy skills were investigated in 41 third-grade children with developmental dyslexia who attended special dyslexia classes in a primary school in Saxony, Germany. Based on the proven efficacy of phonics-based instruction, Lautarium combines training of phoneme perception and phonological awareness with training of grapheme-phoneme-relationships and reading and spelling of transparent words. In addition, rapid access from written words to meaning is included. The children of the training group (N = 27) worked through the program during school lessons, 5 times per week for 30 minutes, for a period of 7 weeks. During the training period, the controls (N = 14) received traditional remedial reading instruction, 2-3 times per week, in small groups. Children's performance in phonological awareness, reading, and spelling was assessed at three time points (pretest, immediate posttest, and follow-up after 9 weeks). Pretest scores did not differ between groups. For spelling and subtests of phonological awareness, group comparisons of raw scores at posttest and follow-up including the respective pretest score as covariate confirmed stronger improvements in the training group when compared to the controls. Effect sizes were medium to strong. For reading, improvements did not differ between groups. In both groups, standard scores (T-scores) for reading and spelling increased significantly and substantially across the study period (from pretest to follow-up). The results confirm the efficacy of computer-based training with Lautarium in children with dyslexia, and the efficacy of school-based remedial instruction provided in the dyslexia classes.

Does noise affect learning? A short review on noise effects on cognitive performance in children.

The present paper provides an overview of research concerning both acute and chronic effects of exposure to noise on children's cognitive performance. Experimental studies addressing the impact of acute exposure showed negative effects on speech perception and listening comprehension. These effects are more pronounced in children as compared to adults. Children with language or attention disorders and second-language learners are still more impaired than age-matched controls. Noise-induced disruption was also found for non-auditory tasks, i.e., serial recall of visually presented lists and reading. The impact of chronic exposure to noise was examined in quasi-experimental studies. Indoor noise and reverberation in classroom settings were found to be associated with poorer performance of the children in verbal tasks. Regarding chronic exposure to aircraft noise, studies consistently found that high exposure is associated with lower reading performance. Even though the reported effects are usually small in magnitude, and confounding variables were not always sufficiently controlled, policy makers responsible for noise abatement should be aware of the potential impact of environmental noise on children's development.

Verbal predicates foster conscious recollection but not familiarity of a task-irrelevant perceptual feature--an ERP study.

Research on the effects of perceptual manipulations on recognition memory has suggested that (a) recollection is selectively influenced by task-relevant information and (b) familiarity can be considered perceptually specific. The present experiment tested divergent assumptions that (a) perceptual features can influence conscious object recollection via verbal code despite being task-irrelevant and that (b) perceptual features do not influence object familiarity if study is verbal-conceptual. At study, subjects named objects and their presentation colour; this was followed by an old/new object recognition test. Event-related potentials (ERP) showed that a study-test manipulation of colour impacted selectively on the ERP effect associated with recollection, while a size manipulation showed no effect. It is concluded that (a) verbal predicates generated at study are potent episodic memory agents that modulate recollection even if the recovered feature information is task-irrelevant and (b) commonly found perceptual match effects on familiarity critically depend on perceptual processing at study.