1 Rotman Research Institute, Baycrest, Toronto, Ontario.
J Int Neuropsychol Soc. 2013 Nov;19(10):1042-52. doi: 10.1017/S1355617713000751. Epub 2013 Aug 7.
The neural organization of cognitive processes, particularly hemispheric lateralization, changes throughout childhood and adolescence. Differences in the neural basis of relational memory between children and adults are not well characterized. In this study we used magnetoencephalography to observe the lateralization differences of hippocampal activation in children and adults during performance of a relational memory task, transverse patterning (TP). The TP task was paired with an elemental control task, which does not depend upon the hippocampus. We contrasted two hypotheses; the compensation hypothesis would suggest that more bilateral activation in children would lead to better TP performance, whereas the maturation hypothesis would predict that a more adult-like right-lateralized pattern of hippocampal activation would lead to better performance. Mean-centered partial least squares analysis was used to determine unique patterns of brain activation specific to each task per group, while diminishing activation that is consistent across tasks. Our findings support the maturation hypothesis that a more adult-like pattern of increased right hippocampal lateralization in children leads to superior performance on the TP task. We also found dynamic changes of lateralization throughout the time course for all three groups, suggesting that caution is needed when interpreting conclusions about brain lateralization.
认知过程的神经组织，特别是大脑两半球的侧化，在整个儿童期和青春期都在发生变化。儿童和成人在关系记忆的神经基础上的差异尚未得到很好的描述。在这项研究中，我们使用脑磁图来观察儿童和成人在执行关系记忆任务（横向模式化，TP）时海马体激活的侧化差异。TP 任务与元素控制任务配对，后者不依赖于海马体。我们对比了两个假设；补偿假设认为，儿童更多的双侧激活会导致更好的 TP 表现，而成熟假设则预测更类似于成人的右侧化的海马体激活模式会导致更好的表现。平均中心化偏最小二乘分析用于确定每个组中每个任务特有的大脑激活模式，同时减少跨任务一致的激活。我们的研究结果支持成熟假设，即儿童中更类似于成人的增加右侧海马体侧化模式会导致 TP 任务表现更好。我们还发现所有三组在整个时间过程中都有侧化的动态变化，这表明在解释大脑侧化的结论时需要谨慎。
