The neural basis of insight problem solving: an event-related potential study

The electrophysiological correlates of successful insight problem solving (Chinese logogriphs) were studied in 18 healthy subjects using high-density event-related potentials (ERPs). A new experimental paradigm (learning-testing model) was adopted in order to make subjects find a solution on their own initiative rather than receive an answer passively. Results showed that Successful guessed logogriphs elicited a more positive ERP deflection (P200-600) than did Unsuccessful guessed logogriphs in the time window from 200 to 600 ms after onset of the stimuli. Subsequently Successful logogriphs elicited a more negative ERP deflection than did Unsuccessful logogriphs in the time windows of 1500-2000 ms (N1500-2000) and 2000-2500 ms (N2000-2500). Maps of the P200-600 showed strong activity in the midline parieto-occipital scalp regions. Dipole analysis localized the generator of P200-600 in the left superior temporal gyrus and parietotemporo-occipital cortex areas. The N1500-2000 and N2000-2500 had a distinct activation over left frontal scalp regions. Dipole analysis localized the generator of the N1500-2000 in the anterior cingulate cortex (ACC) and the N2000-2500 in the posterior cingulate cortex (PCC). This result indicates that the parietotemporo-occipital cortex areas might be involved in forming rich associations in the early stage of successful logogriph solving. Then, the ACC might play an important role in the breaking mental set and the forming of novel associations. At last, "Aha" feeling might activate the PCC.     

Font effects of Chinese characters and pseudo-characters on the N400: evidence for an orthographic processing view

Event-related brain potentials (ERPs) were recorded during a Chinese character decision task to examine whether N400 amplitude is modulated by stimulus font. Results revealed large negative-going ERPs in an N400 time window of 300-500ms to stimuli presented in degraded Xing Kai Ti (XKT) font compared with more intact Song Ti (ST) font regardless of whether the stimuli were real or pseudo-characters. ERPs for the pseudo-characters were more negative than for the real characters with similar timing and scalp distribution. The N400-like font effect on amplitude is interpreted as analogous to an N400 stimulus degradation effect, an extension to Holcomb (1993); the degraded perceptual cues provided by XKT supposedly account for this degradation effect. This effect is further interpreted to reflect relative difficulty, which results from orthographic processing difficulty, in retrieving the meaning of XKT stimuli compared with ST stimuli.     

Chinese character recognition in mirror reading: evidence from event-related potential

As is well known, mirror reading in language requires recognition of words and letters in mirror-reversed pattern compared with normal reading, and the cognitive mechanism underlying the mirror reading may involve two critical processes: visuospatial transformation and linguistic regulation. Chinese characters, different from English, are characterized by some unique features in orthography and spelling. Using ERP techniques, the present study investigated neural correlates underlying the mirror reading of Chinese characters, and whether the cognitive processes underlying the recognition of mirrored Chinese characters is different from those of alphabetic words. Twelve native Chinese speakers participated in the experiment, during which they were instructed to make an animal/nonanimal distinction. The stimuli varied with the word category (animal vs nonanimal) and presentation format (normal vs mirror-reversed). The data analyses focused on three aspects: the reaction times (RT) for Chinese words of normal and mirror-reversed formats, peak latencies, and peak amplitudes of ERP components elicited by mirror-reversed and normal Chinese words. The results from implicit reading provide evidence for a mirror-reversed effect. The behavioural data showed that mirror-reversed words were more difficult to identify than normal words, with RTs delayed for mirror-reversed words over normal words. Moreover, a clear N2 component, with maximal activity occurring at 200-250ms interval (N2), was more negative for mirror-reversed words than for normal words at posterior regions. However, there were no latency differences between normal and mirror-reversed words. The occipital N2 might be closely related to abstract word form representation. Larger N2 amplitude in response to mirror-reversed Chinese words is interpreted as reflecting visuospatial transformation in order to compensate for impaired word form analysis. The result of no N2 latency delay indicated that word form analysis and visuospatial transformation might be processed in parallel.     

Early processing of emotional faces in children with autism: An event-related potential study

Social deficits are one of the most striking manifestations of autism spectrum disorders (ASDs). Among these social deficits, the recognition and understanding of emotional facial expressions has been widely reported to be affected in ASDs. We investigated emotional face processing in children with and without autism using event-related potentials (ERPs). High-functioning children with autism (n = 15, mean age = 10.5 ± 3.3 years) completed an implicit emotional task while visual ERPs were recorded. Two groups of typically developing children (chronological age-matched and verbal equivalent age-matched [both ns = 15, mean age = 7.7 ± 3.8 years]) also participated in this study. The early ERP responses to faces (P1 and N170) were delayed, and the P1 was smaller in children with autism than in typically developing children of the same chronological age, revealing that the first stages of emotional face processing are affected in autism. However, when matched by verbal equivalent age, only P1 amplitude remained affected in autism. Our results suggest that the emotional and facial processing difficulties in autism could start from atypicalities in visual perceptual processes involving rapid feedback to primary visual areas and subsequent holistic processing.     

The influence of spatial representation on valence judgements: An event-related potential study

The present study used event-related potentials (ERPs) to explore the nature of space-valence congruency effects. We presented participants with up or down arrows at the centre of the screen and then asked participants to identify whether the following target words had the emotional valence. The target words included positive emotional words (e.g., “happy” and “delight”), negative emotional words (e.g., “sad” and “depressive”) and neutral words (e.g., “history” and “country”). Behavioural data showed that the positive targets were identified faster when they are primed by up arrows than when primed by down arrows, whereas the negative targets were identified faster when they are primed by down arrows than when primed by up arrows. The ERP analysis showed larger P2 amplitudes were found in the congruent condition (i.e., the positive targets following up arrows or the negative targets following down arrows) than in the incongruent condition (i.e., the positive targets following down arrows or the negative targets following up arrows). Furthermore, larger N400 amplitudes were found in the incongruent condition compared with the congruent condition. Moreover, larger LPC amplitudes were found in the congruent condition compared with the incongruent condition. Therefore, in addition to replicating the space-valence congruency effects in a neutral/emotional judgement task, our study also extended previous studies by showing that spatial information modulates the processing of the emotional words at multiple stages.     

Strategic retrieval processing and the impact of knowing when a memory was first created

Retrieval orientation refers to a process where participants strategically alter how a memory cue is processed in response to different task demands. In the present study we explored whether retrieval orientation is influenced by knowing when an old stimulus was first encoded. Participants completed separate remember/know test blocks for old items from a recent delay (40 min) and old items from a remote delay (48 h). Manipulations at encoding ensured that performance levels were matched between these two blocks, thus avoiding confounds with differences in retrieval effort. Importantly, a third test block comprised old items from both delays randomly intermixed. As the nature of the old items varies unpredictably in the mixed block, it should not be possibly to adopt a specific retrieval orientation and the mixed block therefore acts as a control condition. Participants saw the words “mixed,” “recent” or “remote” prior to each test block. Comparing ERPs from the recent and remote blocks permitted an investigation of whether participants alter their retrieval orientation in response to the specific length of the retention interval. Comparing ERPs from the pure (recent and remote) test blocks to ERPs from the mixed block permitted an investigation of whether delay information per se led to differences in retrieval strategy. Analysis of the ERP data found no differences between the recent and remote blocks. However, ERPs from these pure blocks were significantly less positive than ERPs from the mixed block from 200 ms towards the end of the epoch. The findings suggest that the delay information was useful in a general sense and encouraged retrieval strategies distinct from those engaged in the mixed block. We speculate that such strategies might relate to whether or not the retrieval search is specific and constrained and/or whether processes that serve to reinstate the original encoding context are engaged.     

情绪性注意瞬脱的认知机制:来自行为与ERP的证据

从过度投入理论与激活反弹理论对瓶颈理论的质疑出发,采用ERP技术检验了情绪性注意瞬脱的加工过程及其神经机制。行为结果显示,以恐惧面孔为T1,中性场景图片为T2,则恐惧面孔T1相对中性面孔T1显著降低了中性T2的识别正确率,进而诱发了情绪性注意瞬脱。ERP结果进一步显示,相较于中性面孔T1,恐惧面孔T1诱发的情绪加工影响了代表中枢加工资源的两阶段P3波幅,使得其始终高于代表标准注意瞬脱的中性面孔T1条件和代表非注意瞬脱的单任务基线条件。以上结果证明,情绪性注意瞬脱形成自情绪性T1加工所诱发的中枢资源过度投入,而非源自中枢资源瓶颈。     

Differentiation of stages in joke comprehension: Evidence from an ERP study

This study aimed to investigate the mechanisms underlying joke comprehension using event‐related potentials (ERPs). Fourteen healthy college students were presented with the context of a story without its joke or nonjoke ending, and then, when the story ending was presented, they were asked to make a funny/unfunny judgment about these endings. The behavioral results showed that there was no significant difference between funny and unfunny items, which meant that subjects could understand funny items as easily as unfunny ones. However, the ERP results showed that funny items initially elicited a more negative ERP deflection (N350–450) over frontocentral scalp regions. Dipole analysis localized the generators in the left temporal gyrus and the left medial frontal gyrus; it is suggested that these areas might be involved in detecting the incongruent element in joke comprehension. Between 600 and 800 ms, funny items subsequently elicited a more negative ERP deflection (N600–800) over frontocentral scalp regions and a more positive ERP deflection (P600–800) over posterior scalp regions. Dipole analysis localized the generator in the anterior cingulate cortex (ACC), an area involved in the breaking of mental set/expectation and the forming of novel associations. Finally, funny items elicited a more positive ERP deflection (P1250–1400) over anterior and posterior scalp regions. Dipole analysis localized the generators in the middle frontal gyrus and the fusiform gyrus, areas that might be related to the affective appreciation stage in joke process. Unlike that of Coulson and Kutas (2001), the present study might support the hypothesis of a three stage model of humor processing (humor detection, resolution of incongruity and humor appreciation).     

Different brain mechanisms between stereotype activation and application: evidence from an ERP study

Stereotyping involves two processes in which first, social stereotypes are activated (stereotype activation), and then, stereotypes are applied to given targets (stereotype application). Previous behavioral studies have suggested that these two processes are independent of each other and may have different mechanisms. As few psychophysiological studies have given an integrated account of these stages in stereotyping so far, this study utilized a trait categorization task in which event-related potentials (ERPs) were used to explore the brain mechanisms associated with the processes of stereotype activation and its application. The behavioral (reaction time) and electrophysiological data showed that stereotype activation and application were elicited respectively in an affective valence identification subtask and in a semantic content judgment subtask. The electrophysiological results indicated that the categorization processes involved in stereotype activation to quickly identify stereotypic and nonstereotypic information were quite different from those involved in the application. During the process of stereotype activation, a P2 and N2 effect was observed, indicating that stereotype activation might be facilitated by an early attentional bias. Also, a late positive potential (LPP) was elicited, suggesting that social expectancy violation might be involved. During the process of the stereotype application, electrophysiological data showed a P2 and P3 effect, indicating that stereotype application might be related to the rapid social knowledge identification in semantic representation and thus may be associated with an updating of existing stereotypic contents or a motivation to resolve the inconsistent information. This research strongly suggested that different mechanisms are involved in the stereotype activation and application processes.     

听觉呈现条件下汉语双字词语义和语音启动的ERP研究

在词汇决定实验中研究语义启动和语音启动,材料为通过听觉呈现的汉语双字词组成的词对(间隔600ms),记录行为数据和ERP数据,结果发现：(1)启动词与目标词之间的语义联系可显著改善对目标词的加工,表现为错误率降低、反应时缩短,以及N400波幅降低;(2)启动词与目标词之间的语音一致对目标词的加工既有干扰作用,又有促进作用。表现为错误率提高,但反应时趋向缩短,N400波幅亦呈下降趋势;(3)启动词与目标词首音相同比尾音相同有更大的干扰作用。     

汉字识别的时间进程：来自字谜任务的ERP证据

通过“学习-测试-判断”的三阶段实验范型, 采用事件相关电位（ERP）技术探讨了猜谜任务中对谜底答案（单个汉字）识别的脑内时程动态变化。结果发现：语义识别与字形识别下,汉字刺激均诱发了明显的N1、P2和N2成分,其中语义识别下的P2波幅表现为更加正性,可能与汉字语义的早期加工有关;随后,300-400ms内,语义识别比字形识别诱发了一个更加正性的ERP成分,该成分可能属于P300成分,反映了对汉字语义的进一步整合加工;最后,500-600ms内,语义识别比字形识别同样诱发了一个更加正性的ERP成分,可能反     

Three kinds of rhymes: An ERP study

In a simple prime-target visual rhyming paradigm, pairs of words, nonwords, and single letters elicited similar event-related potential (ERP) rhyming effects in young adults. Within each condition, primes elicited contingent negative variation (CNV) while nonrhyming targets elicited more negative waveforms than rhyming targets within the 320-500ms (N400/N450) time window. The target rhyming effect, apparently primarily an index of phonological processing, was similar across conditions but tended to be smaller in mean amplitude for letters. One of the first reports of such a letter rhyming effect in the ERP literature, these findings could be important developmentally because letter rhyme tasks simultaneously index the two best predictors of ease of learning to read: letter name knowledge and phonological awareness.     

Positive emotion modulates cognitive control: An event‐related potentials study

There is substantial evidence to indicate that negative emotion can modulate cognitive control processing. However, only a few studies have investigated this effect with positive emotion. Therefore, the present study explored the electrophysiological correlates of the impact of positive emotional stimuli on cognitive control, using event‐related potentials (ERPs). Sixteen healthy young adults completed a modified Simon task (Simon, 1969). Behavioral data indicated that reaction times were faster for positive emotional stimuli than for neutral emotional stimuli in the incongruent condition, but not in the congruent condition, which suggested that positive emotion expedited conflict resolution. The ERP data showed that two negative ERP components (N300–400 and N450–550) were associated with the positive emotional stimuli in the incongruent minus congruent condition. It is suggested that these components may respectively be related to the conflict monitoring (N300–400) and response selection (N450–550) stages of cognitive control processing. Overall, our results indicated that positive emotion could facilitate cognitive control processing. These results are in line with the neuropsychological theory, according to which, positive emotion could modulate cognitive control mediated by increased dopamine levels in frontal brain areas.     

An ERP study of sensory mismatch expressions in Japanese

Combinations of different sensory words produce mismatch expressions like smooth color and red touch in contrast to normal expressions like red color and smooth touch. Concerning these sensory mismatch expressions, results of three experiments are reported. Experiment 1 revealed that (i) mismatch expressions were less comprehensible than normal expressions, and that (ii) there were two patterns among mismatch expressions: the high-comprehensible mismatch expression (HighCME, e.g., smooth color) and the low-comprehensible mismatch expression (LowCME, e.g., red touch). Experiment 2 revealed that the mismatch expressions produced a significantly greater N400 amplitude than the normal expressions. Experiment 3 implied that the difference between High/LowCME was reflected in a later latency band or in a topographical difference of N400, although the statistical significance was marginal. It is argued that the processes to integrate linguistic elements (e.g., combining adjectives and nouns) are not homogeneous.     

Brain potentials for derivational morphology: an ERP study of deadjectival nominalizations in Spanish

This study investigates brain potentials to derived word forms in Spanish. Two experiments were performed on derived nominals that differ in terms of their productivity and semantic properties but are otherwise similar, an acceptability judgment task and a reading experiment using event-related brain potentials (ERPs) in which correctly and incorrectly formed derived words were presented in sentence contexts. The first experiment indicated productivity differences between the different nominalization processes in Spanish. The second experiment yielded a pattern of ERP responses that differed from both the familiar lexical-semantic and grammatical ERP effects. Violations of derivational morphology elicited an increased N400 component plus a late positivity (P600), unlike gender-agreement violations, which produced the biphasic LAN/P600 ERP pattern known from previous studies of morpho-syntactic violations. We conclude that the recognition of derived word forms engages both word-level (lexical-semantic) and decompositional (morpheme-based) processes.     

Alterations in error-related brain activity and post-error behavior over time

This study examines the relation between the error-related negativity (ERN) and post-error behavior over time in healthy young adults (N=61). Event-related brain potentials were collected during two sessions of an identical flanker task. Results indicated changes in ERN and post-error accuracy were related across task sessions, with more negative ERN associated with greater improvements in post-error accuracy. This relationship was independent of any cross-sectional relationships between overall task performance, individual difference factors, including personality and self-efficacy, and indices of self-regulatory action monitoring. These results indicate that the relation between ERN and post-error accuracy remains intact and consistent regardless of variation in this set of individual difference factors previously associated with both of these indices of self-regulatory action monitoring, providing support for the strength, robustness, and persistence of this relationship in the process of adaptively controlling behavior to enhance task performance.     

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。     

On the automaticity of emotion processing in words and faces: event-related brain potentials evidence from a superficial task

The degree to which emotional aspects of stimuli are processed automatically is controversial. Here, we assessed the automatic elicitation of emotion-related brain potentials (ERPs) to positive, negative, and neutral words and facial expressions in an easy and superficial face-word discrimination task, for which the emotional valence was irrelevant. Both emotional words and facial expressions impacted ERPs already between 50 and 100 ms after stimulus onset, possibly reflecting rapid relevance detection. Following this initial processing stage only emotionality in faces but not in words was associated with an early posterior negativity (EPN). Therefore, when emotion is irrelevant in a task which requires superficial stimulus analysis, automatically enhanced sensory encoding of emotional content appears to occur only for evolutionary prepared emotional stimuli, as reflected in larger EPN amplitudes to faces, but not to symbolic word stimuli.     

Neural dynamics of animacy processing in language comprehension: ERP evidence from the interpretation of classifier-noun combinations

An event-related potential experiment was conducted to investigate the temporal neural dynamics of animacy processing in the interpretation of classifier-noun combinations. Participants read sentences that had a non-canonical structure, object noun + subject noun + verb + numeral-classifier + adjective. The object noun and its classifier were either (a) congruent, (b) incongruent, but matching in animacy, or (c) incongruent, mismatching in animacy. An N400 effect was observed for both incongruent conditions, but not for additional mismatch in animacy. When only data from participants who accepted the non-canonical structure were analyzed, the animacy mismatch elicited a P600 but still no N400. These findings suggest that animacy information is not used immediately for semantic integration of nouns and their classifiers, but is used in a later analysis reflected by P600. Thus, the temporal neural dynamics of animacy processing in sentence comprehension may be modulated by the relevance of animacy to thematic interpretation.     

Effects of implicit power motive on the processing of anger faces: An event-related potential study

Implicit motives are one form of motivation that regulates cognitive and emotional processing. In this study, we investigated the impact of implicit power motive (nPower) on the processing of anger faces. Event-related potentials were recorded while high- and low-nPower individuals performed a face version of an emotion Stroop task comprised of anger and neutral faces. It was found that nPower does not modify early perceptual and attentional components (P2 and N2), but a later component is affected. Indeed, power-motivated participants showed enhanced P3/LPPs (Late positive potentials) amplitude compared to low-nPower subjects, in response to anger stimuli. These findings demonstrate that anger faces have greater salience for high-nPower individuals and are subject to a more salient, conscious processing.