短时记忆定向遗忘的负荷效应:来自ERP的证据  

The Load Effect on Short-term Memory Directed Forgetting: Evidence from an ERP Study

作　　者：蔡雪丽[1] 高贺明[2] 曹碧华[2] 李富洪[1,2] 

机构地区：[1]西南大学心理学部,重庆400715 [2]辽宁师范大学心理学院,大连116029

出　　处：《心理科学》2015年第3期514-520,共7页Journal of Psychological Science

基　　金：国家自然科学基金(批准号:31300844)的资助

摘　　要：采用事件相关电位（ERPs）技术,通过一个短时记忆测试,考察记忆/遗忘线索在不同的工作记忆负荷条件下诱发的脑电差异。实验以字母和数字为刺激,要求被试记忆或遗忘不同数量的视觉信息。ERP结果发现：在线索呈现230~430ms的时间窗口,高负荷条件的遗忘线索比低负荷条件的遗忘线索诱发了更正的ERPs。这一结果表明,抑制机制在定向遗忘中有重要作用,抑制不同数量的信息需要不同数量的认知资源。Differential rehearsal account and the inhibition account have been proposed to explain the directed forgetting effect, and both accounts have been supported by electrophysiological evidence. We hypothesized that if forgetting was merely a passive process, then there would be no active effort required to process the to-be-forgotten information. Accordingly, there would be no toad effect on the ERPs elicited by forgetting cues. On the contrary, if forgetting was an active process involving cognitive inhibition, then forgetting different amounts of information would require different levels of cognitive resource. Accordingly, the high load of forgetting was expected to be different from the low load of forgetting, reflected by the ERP amplitudes. A novel short-term memory test was used in this study with digits and letters as stimuli. Within each trial, two stimuli were presented sequentially, followed by a cue indicating either the presented items should be remembered or not. The amount of memory information was manipulated （high load condition vs. low load condition）. After an interval （a calculation operation）, subjects were asked to make a response to the probe stimuli. The event related potentials （ERP） were locked to the cues. Fourteen undergraduate students were recruited for the present study. Repeated measures ANOVA with cue, load, candality and electrode site as the within-subjects factors were performed on the mean amplitudes of the ERPs evoked by the cues. The ERP results revealed that： （1） remembering cues evoked more positive ERPs than forgetting cues during the 280-430 ms time window, with a maximum difference at frontal scalp sites; （2） the load effects were observed for both the remembering cues and the forgetting cues. Cues in the high load condition evoked more positive ERPs than that of the low load condition. The ERP results suggested that different cognitive resources were relocated to different cues, as well as to different amount of memory. The marked load effect on

关 键 词：定向遗忘 认知负荷 抑制 ERP 

分 类 号：B842.3[哲学宗教—基础心理学]