Department of Biological and Medical Psychology, University of Bergen, 5009 Bergen, Norway.
Cereb Cortex. 2011 May;21(5):1012-7. doi: 10.1093/cercor/bhq165. Epub 2010 Sep 16.
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.
大脑两半球之间进行高效信息交换对于正在发育的功能侧化大脑至关重要。胼胝体是大脑两半球之间的主要连接，在儿童和青少年时期不断生长。然而，行为研究表明，胼胝体功能发育存在一个关键时期，大约从 6 岁开始。在本纵向研究中，我们对 20 名 6 岁和 8 岁儿童的队列进行了检查，评估了这一时期胼胝体结构和功能发育之间的关系。结构发育通过使用基于磁共振成像的中线胼胝体的形状分析来计算胼胝体厚度的增加来量化。功能发育通过基于双声道呈现辅音-元音音节的语音辨别任务进行评估。统计分析表明，在 2 年的时间里，胼胝体峡部厚度增加的儿童表现出大脑两半球之间信息传递的减少。然而，峡部厚度减少的儿童表现出信息传递的增加。这些结果可能表明，胼胝体连接的细化过程优化了发育中大脑两半球之间的神经元通讯。
