FN400和LPC对熟悉性和回想的特异性指向分析

双加工理论认为熟悉性和回想是情景记忆的两个独立过程,其重要证据是ERP研究中FN400和LPC可以分别指示熟悉性和回想。但也有研究证明FN400是概念启动和熟悉性共同作用的结果,而LPC也不能准确的反映回想加工,因此,将其作为双加工理论证据的可靠性需进一步讨论。未来需进一步明确概念启动和熟悉性影响FN400的前提条件,并在提高生态效度和控制额外变量的同时明晰LPC的指向性,同时探究熟悉性和回想在再认过程中的具体作用方式。     

语义联系对关联再认神经机制的调节

已有研究显示,关联再认可记录到分别反映双重加工模型的两阶段（即熟悉和回忆）的ERP成分（即FN400和LPC成分）,且具有高语义联系配对的关联再认可通过整合在基于熟悉加工的基础上完成。然而,不同语义联系对关联再认神经机制的影响及单个项目的熟悉和回忆加工的调节作用尚未揭示。为此,本研究比较了主题相关和类别相关图形关联再认的波形波幅异同,并分析了单个项目的熟悉和回忆加工对配对识别的影响。结果显示,主题相关和类别相关条件的旧配对、重组配对和“旧+新”配对均记录到反映熟悉加工的FN400成分,主题相关条件的旧配对、重组配对和“旧+新”配对均记录到反映回忆加工的LPC成分,类别相关条件的旧配对记录到LPC成分。表明关联再认的神经机制受语义联系所调节,单个项目的熟悉程度可影响配对识别时的神经机制,上述结论支持双重加工模型。     

The Relation of ERP Components to Complex Memory Processing

The relation between various ERP components generated during encoding of a word and its subsequent recall were investigated using a “rote” serial-order and an “elaborative” category memory task. Words (flashed separately) were time-locked to EEG recordings from 21 cortical sites. ERP components from the five subjects having the highest recall scores were compared to the five lowest scoring subjects. Results based on the P200 peak amplitude data as well as the N400 and late positive component peak amplitude and latency data suggest that anterior and posterior distributional differences are elicited during encoding of words for rote and elaborative memory tasks. Furthermore, strong individual differences in these patterns were found as a function of task. A tentative argument was made that the obtained anterior and posterior differences may index different word feature selection and encoding processes, which are differentially utilized by high and low recallers.     

负面身体自我女性对身体信息的记忆偏向： 来自ERP研究的证据

采用事件相关电位（ERPs）技术探讨了负面身体自我女性（大学生）对胖-瘦两类身体图片进行再认时的脑内时程动态变化。结果发现,相对于控制组（正常女大学生）,胖负面身体自我女大学生在750~800ms的时间窗口内,“胖图”比“瘦图”诱发出一个更正的ERP波形,差异波的地形图显示该正成分在中前部有更强的激活。进一步对差异波作偶极子溯源分析,结果发现,该正成分主要起源于右侧枕叶附近。这似乎表明,右侧枕叶的激活与身体自我信息的出现有关,与负面身体自我图式的体验有关     

The effects of total sleep deprivation on recognition memory processes: A study of event-related potential

This study examined the memorization of information after a night of normal sleep and total sleep deprivation (TSD) by means of event-related potentials (ERPs). We expected a disfacilitatory effect of TSD on memory processing. Eighteen subjects were tested twice in a counterbalanced fashion. During the study session, subjects were presented with unfamiliar face stimuli and asked to memorize them for a subsequent memory test. At the test session, the subjects were presented with the studied faces intermixed with “new” faces and asked to indicate the previously presented stimuli. The N100 was used as a covariate to control for the differences in level of vigilance between the two sessions. Sleep deprivation decreased subjects’ ability to discriminate new from previously studied stimuli and decreased the peak amplitude of the early component (N200) to the decrement of performance. In addition, following TSD the amplitude of the late frontal component (LFC), which is thought to reflect contextual processing, was decreased in covariance with the N100 vigilance component. The amplitude of the late posterior component (LPC/P600) was also reduced but was unrelated to the vigilance component of the ERP. Based on prior studies, this LPC reduction can be interpreted to indicate a decrease in information retrieved after TSD. In summary, a night of TSD decreased the amplitude of the ERPs associated with complex episodic memory task stimuli, affected the frontal cortex during episodic retrieval, and prevented the elaboration process. Furthermore, there was an inability to discriminate what is and what is not in memory, possibly due to less local processing of details.     

作为效应的ERP研究

晚正成分能够反映不同效价和不同唤醒度的情绪。作为后悔的一种现象,作为效应是否与晚正成分具有关联是研究关心的问题。采用运气轮博弈的范式,记录与分析被试在“做”与“不做”决策下的ERPs。研究发现,决策结果的正误显著影响了FRN、P300和LPC的波幅大小。作为类别对FRN、P300和LPC波幅的影响受到不同决策结果的影响,在决策正确的条件下,作为类别对FRN、P300和LPC波幅不产生影响,而在决策错误的条件下,作为类别对FRN、P300和LPC波幅产生了显著的影响。结果表明作为效应不仅影响了FRN、P300的波幅,同时也影响了LPC的波幅,将来研究应进一步探明晚正成分与后悔的密切关联。     

风险对两类跨期选择的影响：一项ERP研究

该研究利用ERP技术,采用伴随风险的跨期选择任务比较了两类跨期选择（立即vs.延迟、延迟vs.延迟）,并探究了风险（零风险、低风险、高风险）对两者跨期选择影响的神经动力学机制。ERP结果显示,对于立即vs.延迟和延迟vs.延迟,在N2和N400上前者大于后者,在LPC上后者大于前者;风险对两者在时程上的影响趋于一致。因此,其加工可能是先对奖赏在风险维度上进行折扣,再与延迟时间进行整合形成奖赏预期,而后做出选择。     

整合对联结再认和项目再认的促进作用：“只有收益”观点

研究旨在探讨整合如何影响联结再认和项目再认及其加工过程。编码阶段要求被试学习复合词和非复合词, 提取阶段完成联结再认和项目再认测验。结果显示, 复合词比非复合词有更好的联结再认表现, 但在项目再认表现上两者之间没有显著的差异。ERP结果显示, 在联结再认上, 复合词诱发显著的FN400效应(与熟悉性加工有关)和LPC效应(与回想加工有关), 非复合词只诱发显著的LPC效应, 且复合词比非复合词有更大的LPC效应。在项目再认上, 复合词比非复合词诱发更大的FN400效应。总而言之, 整合在促进联结再认的同时并不会损害项目再认的表现, 支持了“只有收益”观点。     

Gesture and metaphor comprehension: Electrophysiological evidence of cross-modal coordination by audiovisual stimulation

In recent years, studies have suggested that gestures influence comprehension of linguistic expressions, for example, eliciting an N400 component in response to a speech/gesture mismatch. In this paper, we investigate the role of gestural information in the understanding of metaphors. Event related potentials (ERPs) were recorded while participants viewed video clips of an actor uttering metaphorical expressions and producing bodily gestures that were congruent or incongruent with the metaphorical meaning of such expressions. This modality of stimuli presentation allows a more ecological approach to meaning integration. When ERPs were calculated using gesture stroke as time-lock event, gesture incongruity with metaphorical expression modulated the amplitude of the N400 and of the late positive complex (LPC). This suggests that gestural and speech information are combined online to make sense of the interlocutor’s linguistic production in an early stage of metaphor comprehension. Our data favor the idea that meaning construction is globally integrative and highly context-sensitive.     

条件推理中否定前件下信念偏差发生阶段的ERP研究

以日常生活中的条件推理语句为实验材料,采用大、小前提和结论依次呈现的“推断-判断”范式,利用事件相关电位(event-related brain potential, ERP)技术探讨了条件推理中否定前件下信念偏差效应的脑内时程动态变化。结果发现：在行为反应上,较信念促进,信念阻碍下的正确率更低反应时更长;在脑电上,两条件(信念阻碍和信念促进)诱发的ERP波形仅在大前提加工阶段出现明显的分离。这表明该推理下的信念偏差效应可能早在对大前提的语义表征阶段就已发生。