数学学习困难初中生的记忆广度特点

The Short-Term Memory Span and Working Memory Span of Junior High School Students With Math Learning Disability

记忆广度包括短时记忆广度和工作记忆广度,为揭示数学学习困难学生认知缺损特点,筛选103名初中生(平均年龄12.57岁),比较数学困难学生(49名)与数学优秀学生(54名)的记忆广度差异,通过词语系列任务、阅读广度任务以及倒背数字任务,分别测查短时记忆、言语工作记忆以及数字工作记忆。结果发现,数困组与优秀组的学生在词语系列任务中没有显著差异(t=-1.59,p>.05),在阅读广度任务中,具有显著差异(t=-2.38,p<.05),在倒背数字任务中具有极其显著的差异(t=-4.69,p<.01)。阅读广度和倒背数字之间具有显著相关(r=.24,p<.05),词语系列任务与阅读广度(r=.19,p>.05)和倒背数字任务(r=.05,p>.05)之间不存在显著相关。研究表明,在具有干扰情况的任务更能有效预测数学成绩,数学学习困难的认知缺损主要是对抗干扰的能力不足,而非简单的短时记忆广度。

The study was supposed to discover the cognitive processing mechanism of MLD. Math learning disability （MLD） is an important area of learning disability, accounting for a large percentage of students in the middle schools. Now there emerges a leading paradigm for carrying out research on MLD from the viewpoint of information processing. The study was designed to find out whether the MLD students have deficit in the short-term memory span or the working memory span. The criteria for defining the MLD or math learning disorder of this study was： the math score was lower than 20% of the total score, with normal IQ, and without the obvious organic deficit, emotional disorder and learning motivation disorder. 103 students participated in the study, with 49 MLD students and 54 students who were good at math （with an average age of 12.57 years）. The study designed three experiments such as the word series task to measure short-term memory, the reading span task to measure phonological working memory, and the backward digit span task to measure digit working memory. The reading span task was designed on the computer by the E-prime software, while the other two tasks were oral tests. Each participant spent 30 minutes finishing the experiments with the guidance of psychological graduate students. The results of the study showed： （1） there was no significant difference between two groups in the word series task （ t = - 1.59, p 〉. 05）, but significant difference between two groups in the reading span tasks （ t = - 2.38, p 〈, 05） aswell as the backward digit span task （t =-4.69, p〈. 01）. （2） Correlation analysis showed the reading span task and the backward digit span task had high correlations （ r =. 24, p 〈. 05）, and the word series task had low correlation with the reading span task （r =. 19, p 〉. 05） and backward digit slSan task （r =. 05, p 〉. 05）. （3） The regression analysis indicated that the backward digit span task which measured digit working memory can could better predict math achievement than the other two tasks which measured short-term memory and reading working memory. （4） The developmental trend of memory span among the junior middle school students was not significant. To conclude, MLD students couldn＇t finish the tasks with high loaded working memory demand, but they were able to finish some simple cognitive tasks such as the short-term memory task, which meant that the counter interference and attention control abilities deficit were the core deficit in the MLD.