Hagelthorn K M, Brown W S, Amano S, Asarnow R
Kennedy Krieger Institute, Johns Hopkins University School of Medicine, USA.
Dev Neuropsychol. 2000;18(1):11-31. doi: 10.1207/S15326942DN1801_2.
Implications of the developmental progression of myelination of the corpus callosum were studied using evoked potential interhemispheric transmission time (EP-IHTT) and the bilateral field advantage (BFA) in letter matching. Forty-two normal children aged 7 to 17 years were asked to respond regarding whether 2 letters matched when presented either unilaterally (both in the same visual field) or bilaterally (1 letter in each field). Evoked potentials were recorded with bilateral midparietal electrodes during unilateral presentations of the letter-matching task. Age-related changes were found for both EP-IHTT and BFA. BFA in reaction time in the visual letter-matching task increased significantly with age. Decreasing EP-IHTT with age was also evident (although only in a statistical trend). These findings lend support to the hypothesis that increased callosal myelination during late childhood has functional significance. Callosal maturation appears to result in faster interhemispheric transfer and increasing ability to integrate information across the midline.
利用诱发电位半球间传导时间（EP-IHTT）和字母匹配中的双侧视野优势（BFA），研究了胼胝体髓鞘形成发育进程的影响。42名7至17岁的正常儿童被要求在字母单侧呈现（均在同一视野）或双侧呈现（每个视野各一个字母）时，回答两个字母是否匹配。在字母匹配任务的单侧呈现过程中，用双侧顶叶中部电极记录诱发电位。发现EP-IHTT和BFA均与年龄相关。视觉字母匹配任务中反应时间的BFA随年龄显著增加。随着年龄增长，EP-IHTT也明显缩短（尽管只是在统计学趋势上）。这些发现支持了这样一种假设，即儿童晚期胼胝体髓鞘形成增加具有功能意义。胼胝体成熟似乎导致半球间传递更快，以及跨中线整合信息的能力增强。
