LATERALIZATION OF WORKING MEMORY PROCESSING IN DEVELOPMENT

这个子项目是众多研究子项目之一

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The human brain is separated into two distinct cerebral hemispheres. The two sides of the brain are similar in appearance, and every structure in each hemisphere is mirrored on the other side, yet despite these strong similarities, many functions of each cortical hemisphere are different. Functional neuroimaging research studies have frequently described hemispheric asymmetry reduction in elderly adults. Neuroimaging studies of the developmental trajectory of hemispheric specialization, however, are somewhat limited, and those that exist are contradictory. It has been assumed for a long time that children develop brain lateralization with age. Strong evidence for increased specialization comes from child aphasics (children who lose language abilities because of brain damage) recover from left hemisphere damage more sharply than adults do, and right hemisphere damage seems as likely to result in language deficits as left hemisphere damage. Our research asks if young children (ages 7-12) are lateralized in the same way as older children and adults? fMRI scanning was used to measure brain activity in 14 children and 13 adults (ages 20-29) as they performed spatial and verbal working memory tasks. Behaviorally, the effects of material-type were examined using a 2 x 2 x 3 ANOVA of material x group x load for accuracy across maintenance trials. Adults were more accurate (F (1, 25) = 34.15, p < 0.001) than children. Participants were less accurate at higher loads (main effect of load, F (2, 50) = 41.76, p < 0.001). There was a trend for participants to be less accurate for the spatial (x = 80.8%) than for the verbal (x = 83.6%) WM task, F (1, 25) = 4.09, p < 0.06. The material x group interaction was non-significant (p = 0.17). Together, these behavioral data point to the fact that there are major developmental differences in how fast and accurately children perform.