改进的N-back范式工作记忆认知实验研究

Cognitive Experiment of Improved N- back Paradigm on Working Memory

目的通过改进的n-back认知实验探究两种工作记忆负荷下健康被试的行为学特点、辨识力水平及激活脑区的差异。方法利用SPSS 12.0将实验数据分别从统计学及心理学两个方面进行方差分析和比较,结合SPM的脑区激活图分析脑区负载效应。结果数字组工作记忆负荷比图片组小。各任务间准确率无统计学差异(F=6.317,P>0.05),记忆负荷的增加对反应时间有显著影响(P<0.05),辨识力受任务难度和任务类型影响的交互作用显著(F=4.739,P<0.05),发现两组实验激活脑区有显著差异。结论健康被试行为学表现和辨识力均受刺激材料影响,且与记忆负荷呈负相关。在两组实验中,相关脑区激活范围随记忆负荷的增加并不明显,但部分脑区激活程度增强。

Objective To explore the behavioral characteristics, discernment level and activate brain regions differences of the healthy subjects in the two working memory load conditions by a improved N - back task. Methods The experimental data from the two aspects of the statistics and psychology were compared by SPSS 12.0. The cerebral .effects of memory load were analyzed by SPM. Results The effects of working memory load in the group of digit subjects were lower than the group of pictures subjects. There was no statisti- cally significant difference in the accuracy between two tasks （F = 6. 317, P 〉 0.05 ）. The reaction time were significantly affected by the memory load increases （ P 〈 0.05 ）. The discrimination was significantly affected by interaction between task difficulty and task types （ F = 4. 739,P 〈 0.05 ）. There were significant differences in the two sets of experimental brain areas activated. Conclusion Both the behav- ioral performance and discernment of healthy subjects are influenced by the stimulus material, and negatively correlated with memory load. The related activated brain regions are not obvious with increasing memory load in two experiments, but the activated level of some brain regions increase.