语文学习困难儿童汉字记忆编码的神经机制研究

采用事件相关电位方法,探讨语文学习困难儿童汉字记忆编码过程的特点.研究发现:语文学习困难组和对照组在编码过程的300-700ms均存在显著的相继记忆效应.语文学习困难组与对照组的Dm效应存在着显著的时间与空间上的差异.在Dm效应出现前,语文学习困难组加工的P2潜伏期显著晚于对照组.同时还发现,不同能力组加工的N2和LPC差异与Dm效应十分相似,对照组比语文学习困难组更正,与Dm效应不同,不同能力组加工的分离明显大于Dm效应的分离,且持续时间更长,一直持续到1000ms之后,远远晚于Dm效应的分离时间,对照组比语文学习困难组有一个更正的晚正成分.语文学习困难组与对照组在加工程度上存在差异,使编码项目的记忆痕迹呈现出不同特点.

Chinese Language Learning Disabilities in the ERP Study Memory Encoding

The present research used the ERP paradigm of "learning-recognition"to investigate the brain mechanism during encoding process of keeping character of children who have difficulties in learning Chinese.The results indicated that:(1) for all participants,there was a significant subsequent memory effect between 300ms and 700ms of the encoding process;(2) for the occipital,parietal and central areas,the Dm effect was distributed between 400ms and 700ms during encoding phase,and the wave amplitude of correct recognition was significantly greater than that of false recognition;(3) during extraction stage,between 400ms and 500ms there was a significant old/new effect of occipital region and parietal areas;between 500ms and 700ms there was a significant old/new effect of parietal and central areas,and especially in the central area,the wave amplitude of old character reorganization was larger than the new Chinese characters correct recognition;(4) For the two kinds of processing conditions of Chinese learning disabilities group and control group,there was a significant difference on Dm effect in time and space;(5) Before the onset of the Dm effect,the P2 latency of learning difficulties group was significantly later than that of the control group.We also found that the differences between N2 and LPC of different ability groups were very similar with the Dm effect,the control group was more positive relative than the Chinese learning disabilities group;for the Dm effect is more different,the separation of different ability groups was significantly greater and last longer than that of Dm effect,and till 1000ms later,the time of separation was more longer than that of Dm effect.The control group had a more corrective later positive component.There were differences in the degree of processing between the learning disabilities group and the control group,so that the memory trace of the code project showed different characteristics.