Interhemispheric interaction during childhood: I. Neurologically intact children.
ABSTRACT This study examined the development of interaction between the hemispheres as a function of computational complexity (Banich & Belger, 1990; Belger & Banich, 1992) in 24 children aged 6.5 to 14 years. Participants performed 2 tasks: a less complex physical-identity task and a more complex name-identity task. Children, like adults, exhibit an across-hemisphere advantage on the computationally more complex name-identity task, and neither a within-nor an across-hemisphere advantage for the computationally less complex physical-identity task. Correlations indicated that the younger the child, (a) the greater the size of the within-hemisphere advantage on the less complex task, (b) the greater the size of the across-hemisphere advantage on the more complex task, and (c) the poorer the ability to ignore attentionally distracting information in a selective attention paradigm. These results suggest that interhemispheric interaction in children, like that in adults, serves to deal with the heightened processing demands imposed by increased computational complexity.
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ABSTRACT: The establishment of an efficient exchange of information between the cerebral hemispheres is of crucial importance in the developing functionally lateralized brain. The corpus callosum, the major connection between the cerebral hemispheres, grows constantly throughout childhood and adolescence. However, behavioral studies suggest the existence of a critical time period for callosal functional development starting around the age of 6 years. In the present longitudinal study, examining a cohort of 20 children at the age of 6 and 8 years, we assessed the relationship between structural and functional callosal development during this time period. The structural development was quantified by calculating the increase in callosal thickness using a shape-based computational analysis of the mid-sagittal corpus callosum as obtained with magnetic resonance imaging. The functional development was assessed with a speech discrimination task based on the dichotic presentation of consonant-vowel syllables. The statistical analysis revealed that children whose callosal isthmus increased in thickness over the course of 2 years showed a decrease in interhemispheric information transfer. However, children exhibiting a decrease in isthmus thickness revealed an increase in information transfer. These results might indicate a refinement process of the callosal connections to optimize the neuronal communication between the developing cerebral hemispheres.Cerebral Cortex 05/2011; 21(5):1012-7. · 6.83 Impact Factor
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ABSTRACT: Many studied reported that working memory components receive remarkable changes during lifespan. In order to better investigate this, we evaluated working memory components on human subjects belonging to ﬁve groups (10 subjects each) at different ages 6, 8 and 10 years old, young adult (age) and old adult (age). Our pattern of results shows a major transition in object sequence manipulation performance between ages 8 and 10 years. If related to young adults results, both 10-year- old children and old adults differed in accuracy and RT in both maintenance and manipulation conditions. In particular, young adults and old adults differ in RTs in the manipulation condition. Our results also suggest that a change in response strategy from 6 to 8 years of age, to prioritize accuracy may be present. Our ﬁndings appear consistent with recent neuroscientiﬁc ﬁndings, and lead to novel predictions.Neurological Sciences 06/2014; · 1.41 Impact Factor
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ABSTRACT: Recent studies indicate that the effect of voicing on the ear advantage in dichotic listening might serve as indicator of the development of speech processing abilities in children. In the present longitudinal study, we tested this idea by applying dichotic listening with voiced and unvoiced consonant-vowel syllables. In 35 boys and girls, tested at the age of 5, 6, 7, and 8 years, we found that the effect of voicing increases with age, and that girls were more affected by the voicing characteristics than boys. These results indicate a sex difference in the development of speech processing abilities.Developmental Neuropsychology 11/2010; 35(6):752-61. · 2.90 Impact Factor