ABSTRACT
Two experiments investigated the contribution of phonological short-term memory to the processing of spoken sentences by 4- and 5-year-old children. In Experiment 1, sentences contained either short or longer words, and varied in syntactic structure. Overall, repetition but not comprehension of the sentences was significantly influenced by word length. In Experiment 2. children selected on the basis of their high phonological short-term memory ability were founded to be superior at repeating sentences to children of lower phonological short-term memory ability, although the two groups did not differ in their comprehension accuracy for the same sentences. In both experiments, comprehension and repetition performance were differently influenced by particular sentence structures. It is proposed that sentence repetition in children is constrained by phonological memory capacity, and is therefore directly influenced by memory-related factors that include the length and number of words in sentences, and individual differences in memory skills.
Subject(s)
Cognition/physiology , Language , Memory, Short-Term/physiology , Phonetics , Child, Preschool , Humans , Psychological TestsABSTRACT
This article presents findings from the Children's Test of Nonword Repetition (CNRep). Normative data based on its administration to over 600 children aged between four and nine years are reported. Close developmental links are established between CNRep scores and vocabulary, reading, and comprehensive skills in children during the early school years. The links between nonword repetition and language skills are shown to be consistently higher and more specific than those obtained between language skills and another simple verbal task with a significant phonological memory component, auditory digit span. The psychological mechanisms underpinning these distinctive developmental relationships between nonword repetition and language development are considered.
Subject(s)
Language Development Disorders/diagnosis , Language Tests , Memory, Short-Term , Phonetics , Psychometrics , Case-Control Studies , Child , Child, Preschool , Cognition , England , Female , Humans , Male , Memory , Neuropsychological Tests , Reading , Reference Values , Reproducibility of Results , Speech , Tape Recording , VocabularyABSTRACT
Blood leukocyte cultures were incubated with antioxidants and the carcinogens sodium cyclamate and 7,12-dimethylbenz(alpha)anthracene in different combinations. There were 17.4% more chromosomal breaks in the group of cells treated with dimethylbenzanthracene only than in the untreated controls. The reductions in chromosomal breaks by the antioxidants were as follows: ascorbic acid, 31.7%; butylated hydroxytoluene, 63.8%; Na(2)SeO(3), 42.0%; and dl-alpha-tocopherol, 63.2%. Multiple chromosomal breaks were distributed equally throughout the experimental groups. Sodium cyclamate had only slightly more chromosomal breaks than the controls (11.6 compared to 10.9%). In the cyclamate groups treated with Na(2)SeO(3), 11.2% of chromosomes were broken. More acrocentric-type chromosomal breaks (21.7%) were seen in the untreated cells than the cells treated with cyclamate (3.4%) or dimethylbenzanthracene alone (4.8%). The carcinogen-treated groups had a higher percentage of meta breaks than the untreated controls.
