三字字谜顿悟的时频特征与源定位

运用事件相关电位(ERPs)技术,采用猜谜任务范式,从字谜问题解决中谜底“催化”所诱发顿悟的时间过程和源定位两方面来探讨顿悟的认知神经机制。脑电时程分析显示,在320-550ms内,“有顿悟”较“无顿悟”的ERP波形有一个更大的负向偏移,且在“有顿悟-无顿悟”差异波中,该负成分的潜伏期约为380ms,差异波的脑电峰值锁定在Cz点。EEG时频则显示N380主要表现为减弱的高频gamma波和beta波的频谱特征。独立成分溯源结果显示,N380存在四个独立源,主要分布在右侧额中回、左侧顶下小叶、右侧颞上回和右侧额下回。这些结果表明,三字字谜顿悟的N380就是N400,且主要负责三字顿悟字谜外显含义到内隐隐喻意义的表征转换加工。     

工作记忆中汉字与空间的分离及动态优势半球的ERP效应

测量了14名正常被试完成延迟匹配任务时的事件相关脑电位(ERP)。在刺激消失后的延迟阶段,汉字任务和空间任务均在头皮中前部额区产生P260和晚期正成分(LPC), 在头皮后部顶枕区产生N150和晚期负成分(LNC)。汉字任务的P260表现出右脑优势, 400-800ms时LPC转变为与空间任务相比较的汉字左脑相对优势。空间任务的P260在左右脑无差异,400-800ms时LPC转变为右脑优势。头皮后部无显著差异。本研究提供了工作记忆中汉字与空间信息保持的分离及其优势脑动态变化的ERP证据。     

新颖语义联结形成的右半球优势效应

新颖语义联结形成是创造性思维的重要加工过程。采用谜题型歇后语为材料,直接操控语义联结的新颖性,通过两个实验考察汉语新颖语义联结形成的神经机制。实验1采用fMRI记录谜题型歇后语阅读理解过程的神经活动,结果显示相对于寻常语义关联条件,新颖语义关联条件更强地激活了右侧颞上回,该脑区可能与新颖语义信息的激活有关。实验2采用ERP技术在语义关联性判断任务中考察新颖语义联结形成神经加工的时空特征,结果显示相对于寻常语义关联条件,新颖语义关联条件在右侧颞区和右侧额区诱发了更正的晚期正成分,可能分别反映了新颖语义信息的激活以及选择与整合。研究结果支持了新颖语义联结形成的右半球加工优势效应。     

When a Dog Has a Pen for a Tail: the Time Course of Creative Object Processing

Creative objects differ from ordinary objects in that they are created by human beings to contain novel, creative information. Previous research has demonstrated that ordinary object processing involves both a perceptual process for analyzing different features of the visual input and a higher-order process for evaluating the relevance of this visual information. However, it is unclear how and when these processes are influenced by the creative information of the object. This study utilized event-related potentials (ERPs) to investigate the time course of creative object processing. Behavioral results revealed that participants spent more time processing creative objects than they did ordinary objects. Analysis of scalp ERPs further revealed that creative objects elicited a more negative ERP deflection between 190 and 340 ms (N190–340) with an anterior scalp distribution. Additionally, creative objects elicited more positive ERP deflection than did ordinary objects between 400 and 700 ms (P400–700) with a right centro–parietal scalp distribution and between 700 and 1000 ms (late positive component) with a right anterior–central scalp distribution. Such results suggest that the processing of creative objects is composed of two distinct stages. The early perceptual stage involves the detection of visual differences exhibited by the creative objects, while the late stage involves the right-lateralized processes of understanding and encoding the creative information.     

Musicians processing music: Measurement of brain potentials with EEG

Abstract

In the present study, the EEG was recorded from the scalp of musicians while mentally active in their field. Analytic, creative and memory processes of the brain were observable using a special electrophysiological method called DC-potential recording. Music students listened to a sequence of four notes and subsequently were either to reverse the sequence (task 1 = analytic) or to compose a new continuation (task 2 = creative). In task 3, the initial segment of a well-known melody was presented and had to be continued (memory task). All tasks had to be solved mentally (imagery). In tasks 1 and 2, either tonal or atonal sequences were presented.

While processing, the results show that the analytic task elicited the highest brain activity. The analytic task involved mainly parieto-temporal areas of both hemispheres, the left hemisphere showing a tendency for domination. The memory task produced predominant activity over the right hemisphere. The creative task caused the lowest brain activation and elicited an unexpected lateralisation to the left, though we expected creativity to be a right hemispheric holistic-synthetic phenomenon.

Comparing listening with processing of the perceived music, we found a significant shift from an insignificant right hemispheric to an insignificant left hemispheric predominance (except with the memory task). This indicates that musicians do not lateralise to the left hemisphere per se when listening to music. Whether one finds a left hemispheric lateralisation in listening tasks or a right hemispheric one probably depends on the amount of simultaneous analytic-sequential processing the musician undertakes.     

Right hemisphere sensitivity to word- and sentence-level context: evidence from event-related brain potentials

Researchers using lateralized stimuli have suggested that the left hemisphere is sensitive to sentence-level context, whereas the right hemisphere (RH) primarily processes word-level meaning. The authors investigated this message-blind RH model by measuring associative priming with event-related brain potentials (ERPs). For word pairs in isolation, associated words elicited more positive ERPs than unassociated words with similar magnitudes and onset latencies in both visual fields. Embedded in sentences, these same pairs showed large sentential context effects in both fields. Small effects of association were observed, confined to incongruous sentences after right visual hemifield presentation but present for both congruous and incongruous sentences after left visual hemifield presentation. Results do not support the message-blind RH model but do suggest hemispheric asymmetries in the use of word and sentence context during real-time processing.     

Hemispheric differences in strong versus weak semantic priming: evidence from event-related brain potentials

GOALS: Research with lateralized word presentation has suggested that strong ("close") and weak ("remote") semantic associates are processed differently in the left and right cerebral hemispheres [e.g., Beeman, M. j., & Chiarello, C. (1998). Complementary right- and left-hemisphere language comprehension. Current Directions in Psychological Science, 7(1), 2-8]. Recently, this hypothesis has been challenged [Coney, J. (2002). The effect of associative strength on priming in the cerebral hemispheres. Brain and Cognition, 50(2), 234-241]. We predicted that foveal presentation of strong and weak associates would elicit different patterns of hemispheric activity, as indexed by high-density event-related brain potentials (ERPs), and that source localization of the scalp potentials would help clarify the nature of hemispheric contributions to semantic organization. METHODS: 128-channel ERPs were recorded in two experiments as subjects performed a lexical decision task. Word trials were equally divided into strongly related, weakly related, and unrelated word pairs. All words were foveally presented. SOA was 800 ms in Experiment 1, and 200 ms in Experiment 2. RESULTS: Topographic analyses revealed medial frontal (MFN) and parietal (N400/LPC) effects for both strong and weak associates. Between approximately 450 and 550 ms, the magnitude of the N400/LPC effect indicated priming for both strong and weak associates over left parietal sites, while priming over right parietal sites was restricted to strongly related word pairs. During this interval, spatiotemporal source modeling showed that these scalp effects were best accounted for by ipsilateral sources in the medial temporal lobe. The observed pattern of asymmetries for strong versus weak associates is not consistent with certain proposals regarding the complementarity of right- and left-hemisphere contributions to semantics. It is, however, consistent with findings from visual half-field studies (Hasbrooke and Chiarello, 1998). We discuss the relevance of these results for theories of hemispheric asymmetry and meta-control in lexical semantic access.     

奖励驱动的双任务加工过程中的分离脑机制：来自ERP的证据

运用事件相关电位技术, 采用分支双任务范式, 探讨在奖励驱动的双任务加工过程中, 第一任务奖励编码和第二任务奖励编码的时间进程及其脑机制。结果发现：双任务的反应时显著大于单任务的反应时; 单任务的N2波幅显著大于双任务条件; 双任务的P3波幅显著大于单任务条件。双任务加工过程中奖励编码的半球效应主要体现在P3上, 且右半球参与第一任务奖励信息的编码, 驱动第一任务; 两半球协同参与第二任务奖励信息的编码, 驱动第二任务。结果表明：双任务所耗费的心理资源更多, 同时双任务加工过程中第一任务奖励信息编码的半球优势效应与任务的性质有关。     

Hemispheric specialization and creative thinking: A meta-analytic review of lateralization of creativity

In the last two decades research on the neurophysiological processes of creativity has found contradicting results. Whereas most research suggests right hemisphere dominance in creative thinking, left-hemisphere dominance has also been reported. The present research is a meta-analytic review of the literature to establish how creative thinking relates to relative hemispheric dominance. The analysis was performed on the basis of a non-parametric vote-counting approach and effect-size calculations of Cramer’s phi suggest relative dominance of the right hemisphere during creative thinking. Moderator analyses revealed no difference in predominant right-hemispheric activation for verbal vs. figural tasks, holistic vs. analytical tasks, and context-dependent vs. context-independent tasks. Suggestions for further investigations with the meta-analytic and neuroscience methodologies to answer the questions of left hemispheric activation and further moderation of the effects are discussed.     

语义距离半球效应的ERP研究

以通过视觉通路呈现的汉语双字词为实验材料,操纵启动词与目标词的语义距离。在词汇决定实验中记录ERP,发现：（1）除N300外,P240亦对语义距离敏感,它可能是一种与语义加工有关的新的ERP成分;（2）P240在头皮中央偏左的部位较早出现,但在头皮右侧波幅较大;（3）N300和P240都不存在语义距离的半球效应,该结果没有证实右脑更专擅远距离语义加工的假设,表明使用汉语与使用拼音文字的脑机制存在差异。     

再探猜谜作业中“顿悟”的ERP效应

采用事件相关电位(ERP)技术探讨顿悟问题（字谜）解决中提供答案后的脑内时程动态变化。结果发现,在250~400 ms内,“有顿悟”和“不理解”比“无顿悟”的ERP波形均有一个更为负向的偏移。在“有顿悟—无顿悟”和“不理解—无顿悟”的差异波中,这个负成分的潜伏期约为320 ms (N320),地形图显示,N320在中后部活动最强。进一步对“有顿悟—无顿悟”差异波作偶极子溯源分析,发现N320主要起源于扣带前回（ACC）附近。这似乎表明,N320可能反映了提供答案瞬间新旧思路之间的认知冲突,但是却不能真正揭示顿悟问题解决中思维定势的成功突破以及“恍然大悟”所对应的独特脑内时程变化     

异同判断中“快同效应”的大脑机制：一项ERP研究

采用高密度的事件相关电位（ERPs）技术,记录分析了大学生被试在执行异同判断任务[包括不同颜色刺激对（DC）,不同形状刺激对（DS）和相同刺激对（Same）]时的脑内时程动态变化。行为结果表明,“同”反应的确显著快于“异”反应,表现出明显的快同效应。ERP结果显示：在280-320 ms内,DS和DC条件均比Same条件诱发一个更负的N2成分。偶极子溯源分析表明,DC和DS条件下,N2可能起源于大脑的前扣带皮层（ACC）,可能与“异”反应早期不一致信息（颜色或形状）的认知监控和调节有关;反之Same条件下,N2成分可能起源于楔前叶,主要反映了“同”反应早期知觉识别中整体特征比较加工的过程（同一性指示器）。另外,在450 ms左右, DC和DS比Same条件均诱发了一个更负的P3成分,可能反映了对刺激局部特征的比较和识别（慢速比较器）,并与选择性注意和资源分配等高级认知活动有关;并且,Same条件下P3成分的潜伏期更短,与行为结果一致。以上研究结果表明,异同判断中“同”反应和“异”反应可能有着不同的比较通道和大脑机制,支持双过程模型理论;同时表明,慢速比较器和同一性指示器可能是序列加工的。     

Electrophysiological correlates of impaired reading in dyslexic pre-adolescent children

In this study, event related potentials (ERPs) were used to investigate the extent to which dyslexics (aged 9-13 years) differ from normally reading controls in early ERPs, which reflect prelexical orthographic processing, and in late ERPs, which reflect implicit phonological processing. The participants performed an implicit reading task, which was manipulated in terms of letter-specific processing, orthographic familiarity, and phonological structure. Comparing consonant- and symbol sequences, the results showed significant differences in the P1 and N1 waveforms in the control but not in the dyslexic group. The reduced P1 and N1 effects in pre-adolescent children with dyslexia suggest a lack of visual specialization for letter-processing. The P1 and N1 components were not sensitive to the familiar vs. less familiar orthographic sequence contrast. The amplitude of the later N320 component was larger for phonologically legal (pseudowords) compared to illegal (consonant sequences) items in both controls and dyslexics. However, the topographic differences showed that the controls were more left-lateralized than the dyslexics. We suggest that the development of the mechanisms that support literacy skills in dyslexics is both delayed and follows a non-normal developmental path. This contributes to the hemispheric differences observed and might reflect a compensatory mechanism in dyslexics.     

内隐多效性选择的ERP证据

采用事件相关电位技术,考察内隐多效性选择及其神经机制。被试的任务是认真观看配对的纯色图片刺激,并进行分类按键反应。实验结果发现,在P2上,积极启动刺激比对照刺激激发了更大的P2波幅; 对比对照刺激,积极启动刺激在左脑、大脑中部和后脑诱发了更大的P2波幅,其中右脑的效应最大。在N2上,积极启动刺激比对照刺激激发了更小的N2波幅; 对比对照刺激,积极启动刺激在左脑、大脑中部和后脑诱发了更小的N2波幅,其中右脑的效应最大。在P3上,积极启动刺激比对照刺激激发了更大的P3波幅; 对比对照刺激,积极启动刺激在左脑、大脑中部和后脑诱发了更大的P3波幅,其中右脑的效应最大。研究结果表明当外显目标与内隐目标同时被呈现时,被试趋向于做多效性选择,这可能表明无意识信息加工具有相当大的权重。且右后部脑区可能是加工多效性刺激的核心和关键区域,P3成分可能反应了内隐多效性选择的精细加工过程,能够作为内隐多效性选择的有效的ERPs指标。     

新颖性图像加工的时间进程

采用ERPs技术,考察了个体新颖性图像加工的时间进程。行为结果表明: 新颖性图像的判断时间更长。ERPs结果显示:新颖与非新颖图像在刺激呈现后190–340ms诱发出明显的前额区N190–340,但在波幅上无显著差异;在400–600ms以及600–1000ms,新颖性图像在顶区与额–中央区, 特别在右侧半球诱发出更大的正性偏移(P400–600和LPC)。研究表明: 图像新颖性属性的识别主要发生在涉及图像特征融合、图像记忆编码等多项认知活动参与的晚期加工阶段,并存在半球右侧化效应。     

本族效应的认知神经机制

本族效应是指个体对本族面孔比异族面孔有更好的再认的现象。本族面孔和异族面孔诱发的N170、P200、N200与“DM”效应存在显著差异, 这些脑电成分与本族效应的编码有关, 即对异族面孔编码不充分是本族效应产生的部分原因; “新旧”效应主要从提取角度解释本族效应, 认为提取异族面孔比本族面孔困难。与本族效应有关的主要脑区有梭状回、扣带回与杏仁核等。此外, 丰富的本族面孔知觉经验也会造成本族面孔的右半球优势比异族面孔大。未来研究除了要继续探讨本族效应的某些脑电成分、关注本族效应消失的神经机制以外, 从整合观点探讨本族效应的神经机制也是未来的研究方向。     

ERP signatures of conscious and unconscious word and letter perception in an inattentional blindness paradigm

A three-phase inattentional blindness paradigm was combined with ERPs. While participants performed a distracter task, line segments in the background formed words or consonant-strings. Nearly half of the participants failed to notice these word-forms and were deemed inattentionally blind. All participants noticed the word-forms in phase 2 of the experiment while they performed the same distracter task. In the final phase, participants performed a task on the word-forms. In all phases, including during inattentional blindness, word-forms elicited distinct ERPs during early latencies (∼200–280 ms) suggesting unconscious orthographic processing. A subsequent ERP (∼320–380 ms) similar to the visual awareness negativity appeared only when subjects were aware of the word-forms, regardless of the task. Finally, word-forms elicited a P3b (∼400–550 ms) only when these stimuli were task-relevant. These results are consistent with previous inattentional blindness studies and help distinguish brain activity associated with pre- and post-perceptual processing from correlates of conscious perception.     

Comparison of brain mechanisms underlying the processing of Chinese characters and pseudo-characters: an event-related potential study

Most Chinese characters are composed of a semantic radical on the left and a phonetic radical on the right. The semantic radical provides the semantic information; the phonetic radical provides information concerning the pronunciation of the whole character. The pseudo‐characters in the study consisted of different sub‐lexical parts of real Chinese characters and consequently they also had the semantic radical and the phonetic radical. But they were not readable and had no actual meaning. In order to investigate the spatiotemporal cortical activation patterns underlying the orthographic, phonological and semantic processing of Chinese characters, we used event‐related brain potentials (ERPs) to explore the processing of Chinese characters and pseudo‐characters when 14 healthy Chinese college students viewed the characters passively. Results showed that both Chinese characters and pseudo‐characters elicited an evident negative potential peaking around 120 ms (N120), which appeared to reflect initial orthographic distinction and evaluation. Then, Chinese pseudo‐characters elicited a more positive ERP deflection (P220) than did Chinese characters 200–250 ms after onset of the stimuli. It was similar to the recognition potential (RP) and might reflect the integration processes of phonological and semantic processing on the basis of early orthographic information. Dipole source analysis of the difference wave (pseudo‐characters minus characters) indicated that a generator localized in the left temporal‐occipital junction contributed to this effect, which was possibly related to phonological and perceptual–semantic information integration. Between 350–450 ms, a greater negativity (N360) in pseudo‐characters as compared to characters was found over midline fronto‐central scalp regions. Dipole analysis localized the generator of N360 in the right parahippocampal cortex. Therefore, the N360 might be an N400 component and reflect the higher‐level semantic activation on the basis of orthographic, phonological and perceptual–semantic processing.     

Right hemispheric dominance in gaze-triggered reflexive shift of attention in humans

Recent findings suggest a right hemispheric dominance in gaze-triggered shifts of attention. The aim of this study was to clarify the dominant hemisphere in the gaze processing that mediates attentional shift. A target localization task, with preceding non-predicative gaze cues presented to each visual field, was undertaken by 44 healthy subjects, measuring reaction time (RT). A face identification task was also given to determine hemispheric dominance in face processing for each subject. RT differences between valid and invalid cues were larger when presented in the left rather than the right visual field. This held true regardless of individual hemispheric dominance in face processing. Together, these results indicate right hemispheric dominance in gaze-triggered reflexive shifts of attention in normal healthy subjects.     

不同性质的汉语高熟悉度隐喻意义加工过程——来自ERP研究的证据

采用ERP技术考察不同性质隐喻加工的时间进程与神经机制。以词对方式呈现词源性隐喻、引发性隐喻、一般字面义,被试进行语义相关判断任务。结果发现:从引发性隐喻、一般字面义到词源性隐喻,N400平均波幅呈阶梯状递减,引发性隐喻和词源性隐喻的P600平均波幅大于一般字面义。对于不同类型词对诱发的N400,大脑左半球没有显著差异,但右半球上引发性隐喻显著大于词源性隐喻和字面义词对。并且右半球P600平均波幅更大,但三种词对间没有显著差异。结果表明:(1)日常熟悉隐喻的理解更符合平行假说但需要更多的认知资源;(2)右半球是否参与以及参与程度与隐喻性质和加工阶段有关。