Perceptual context and individual differences in the language proficiency of preschool children.

Although the contribution of perceptual processes to language skills during infancy is well recognized, the role of perception in linguistic processing beyond infancy is not well understood. In the experiments reported here, we asked whether manipulating the perceptual context in which stimuli are presented across trials influences how preschool children perform visual (shape-size identification; Experiment 1) and auditory (syllable identification; Experiment 2) tasks. Another goal was to determine whether the sensitivity to perceptual context can explain part of the variance in oral language skills in typically developing preschool children. Perceptual context was manipulated by changing the relative frequency with which target visual (Experiment 1) and auditory (Experiment 2) stimuli were presented in arrays of fixed size, and identification of the target stimuli was tested. Oral language skills were assessed using vocabulary, word definition, and phonological awareness tasks. Changes in perceptual context influenced the performance of the majority of children on both identification tasks. Sensitivity to perceptual context accounted for 7% to 15% of the variance in language scores. We suggest that context effects are an outcome of a statistical learning process. Therefore, the current findings demonstrate that statistical learning can facilitate both visual and auditory identification processes in preschool children. Furthermore, consistent with previous findings in infants and in older children and adults, individual differences in statistical learning were found to be associated with individual differences in language skills of preschool children.

Phonological memory and word learning deficits in children with specific language impairment: A role for perceptual context?

BACKGROUND: Sensitivity to perceptual context (anchoring) has been suggested to contribute to the development of both oral- and written-language skills, but studies of this idea in children have been rare. AIMS: To determine whether deficient anchoring contributes to the phonological memory and word learning deficits of children with specific language impairment (SLI). METHODS AND PROCEDURES: 84 preschool children with and without SLI participated in the study. Anchoring to repeated items was evaluated in two tasks - a phonological memory task and a pseudo-word learning task. OUTCOMES AND RESULTS: Compared to children with typical development, children with SLI had poorer phonological memory spans and learned fewer words during the word learning task. In both tasks the poorer performance of children with SLI reflected a smaller effect of anchoring that was manifested in a smaller effect of item repetition on performance. Furthermore, across the entire sample anchoring was significantly correlated with performance in vocabulary and grammar tasks. CONCLUSIONS AND IMPLICATIONS: These findings are consistent with the hypothesis that anchoring contributes to language skills and that children with SLI have impaired anchoring, although further studies are required to determine the role of anchoring in language development.

Auditory working memory and early reading skills in Hebrew-speaking preschool children.

The hypothesis that different subcomponents of auditory working memory are differentially related to early reading skills was tested in 63 Hebrew speaking 4-year-old children, using a battery of early reading (phonological processing and familiarity with written language) and memory (simple and complex spans) tasks. Complex spans accounted for significant amounts of variance on both facets of early reading even after the contribution of simple spans was accounted for. These findings suggest that the unique contribution of complex working memory to early reading can be identified as early as preschool and that the structure of correlations between reading and memory is similar across ages.

Anchoring in 4- to 6-year-old children relates to predictors of reading.

Previous studies suggest that anchoring, a short-term dynamic and implicit process that allows individuals to benefit from contextual information embedded in stimulus sequences, might be causally related to reading acquisition. Here we report findings from two experiments in which two previously untested predictions derived from this anchoring hypothesis were tested: (a) that anchoring facilitates rapid naming and phonological short-term memory in children prior to the onset of formal reading instruction and (b) that anchoring makes a unique contribution to performance in two early predictors of reading (letter knowledge and phonological awareness). In line with those predictions, naming times were faster and memory spans were longer under conditions that encouraged the use of anchoring processes than under conditions that afforded little anchoring. Furthermore, performance in the anchoring-affording condition predicted significant amounts of variance in phonological awareness and letter knowledge even after controlling for the contribution of the conditions that did not afford anchoring. Therefore, we suggest that anchoring might contribute to the development of reading-related processes during the preschool years independent of the development of specific reading-related skills such as phonological processing.

Perceptual anchoring in preschool children: not adultlike, but there.

BACKGROUND: Recent studies suggest that human auditory perception follows a prolonged developmental trajectory, sometimes continuing well into adolescence. Whereas both sensory and cognitive accounts have been proposed, the development of the ability to base current perceptual decisions on prior information, an ability that strongly benefits adult perception, has not been directly explored. Here we ask whether the auditory frequency discrimination of preschool children also improves when given the opportunity to use previously presented standard stimuli as perceptual anchors, and whether the magnitude of this anchoring effect undergoes developmental changes. METHODOLOGY/PRINCIPAL FINDINGS: Frequency discrimination was tested using two adaptive same/different protocols. In one protocol (with-reference), a repeated 1-kHz standard tone was presented repeatedly across trials. In the other (no-reference), no such repetitions occurred. Verbal memory and early reading skills were also evaluated to determine if the pattern of correlations between frequency discrimination, memory and literacy is similar to that previously reported in older children and adults. Preschool children were significantly more sensitive in the with-reference than in the no-reference condition, but the magnitude of this anchoring effect was smaller than that observed in adults. The pattern of correlations among discrimination thresholds, memory and literacy replicated previous reports in older children. CONCLUSIONS/SIGNIFICANCE: The processes allowing the use of context to form perceptual anchors are already functional among preschool children, albeit to a lesser extent than in adults. Nevertheless, immature anchoring cannot fully account for the poorer frequency discrimination abilities of young children. That anchoring is present among the majority of typically developing preschool children suggests that the anchoring deficits observed among individuals with dyslexia represent a true deficit rather than a developmental delay.

Cerebral palsy--long-term medical, functional, educational, and psychosocial outcomes.

Cerebral palsy, typically diagnosed in childhood, clearly continues into adulthood. This study describes the long-term medical, functional, educational, and psychosocial outcomes of people with cerebral palsy. Of the 203 people with cerebral palsy diagnosed and treated at the Child Development Center in Tel Aviv between 1975 and 1994, 163 (80%; age range 8-30 years, mean age 18.9 years, and median age 19 years) participated in a cross-sectional telephone survey. Half the respondents have chronic health problems: 78% report they experience gross motor disability, of whom 22% are wheelchair users; 30% to 50% need help in various activities of daily living; 35% have mental retardation; 79% completed 12 years or more of schooling; 78% live with their parents; 25% have served in the army; 23% have a driver's license; and 23% work in competitive employment. The large majority is involved in varied leisure activities and report a high level of life satisfaction.

A Long-term, epidemiological survey of outcome and adjustment of children with developmental disabilities.

The medical, educational, and psychosocial outcomes of 3224 subjects (age range, 7-33 years; mean age, 20.06 years; SD, 5.74) diagnosed and treated in the Institute for Child Development in Tel Aviv between the years 1975 and 1994 were assessed by a telephone interview. Results indicate that only 9% of the subjects are seriously disabled, and 8% are mentally retarded. Over the years, subjects were referred to the Child Development Center at an increasingly younger age, probably reflecting greater professional and parental awareness of the importance of early intervention. The nature of interventions changed, so that physiotherapy, occupational therapy, and psychological guidance were more often provided. While more children were referred to special education at kindergarten, the percentage of those graduating from regular schools has increased. Most completed 12 years of schooling and successfully acquired full or partial matriculation certificates. As adults, most function independently; fulfill civic obligations, such as their army service; are fully employed; and express satisfaction with their life. These results suggest that children with developmental disabilities who receive early intervention are likely to be functionally independent and to be satisfied with their lives, although they continue to need medical services and require some government support. Further studies are essential to examine the correlation of specific risk factors and early interventions with outcome.