汉语单字词音、义加工的脑激活模式

目的：研究汉字音、义加工的脑机制。方法：采用汉字单字词为实验材料，通过功能磁共振成像扫描执行语音和语义两种认知任务的脑区。结果：语音任务激活的脑区有，左侧顶叶下部和颞上回(BA 40／39／22，BA：Brodmann Area，即布鲁德曼分区，下同)，左侧枕中回(BA18／19)，右侧枕下回(BA18／19)，以及左中央前回(BA6)。语义任务激活的脑区有，左侧顶叶下部(BA40／39)和左侧颞上回(BA22)，左侧额下回(BA10／47)，右侧额中回和额上回(BA10／11)，以及左侧额中回(BA11)。语义任务减去语音任务激活的脑区有，左侧额下回(BA47)，左侧海马(BA36)和右侧海马旁回(BA36)。语音任务减去语义任务没有发现任何脑区的显著激活。结论：在语义任务中与语音有关的脑区得到激活；而在语音任务中与语义有关的脑区没有激活。     

正常人汉字工作记忆功能磁共振脑激活区改变的研究

目的探讨正常人汉字任务下脑激活区的改变。方法对40例正常人进行汉字工作记忆功能磁共振扫描。结果汉字工作记忆任务下,编码、保持及提取期均有额叶、楔前叶、楔叶、边缘叶及扣带回的正向激活,且有侧脑室及脑脊液在编码及保持期的正向激活和在提取期的负向激活。除共同激活脑区外,编码期所有激活脑区均为正向激活,保持期正向激活脑区有中央前回、杏仁核、上后扣带皮层(BA 31),负向激活脑区有颞中回、顶叶、角回,提取期正向激活脑区有尾状核。结论汉字任务下,脑激活区的改变除皮层及皮层下结构,还有侧脑室及脑脊液的激活。     

维吾尔语语义加工脑功能定位的磁共振成像研究

目的 利用功能磁共振(fMRI)技术研究维吾尔族对其母语(维吾尔文字)进行词义联想脑功能的激活区及语言的偏侧化.方法 29例健康志愿者作为受试对象,通过视觉刺激对每个单音节实词进行词义联想同时行fMRI,所有数据经神经功能分析软件对相关脑皮质激活区进行个体分析及组分析.结果 多个皮质出现激活区,主要出现在双侧额中回、额下回、枕中回、中央前回及梭状回,左侧颞中回、顶上下小叶、楔前叶,右侧颞上回、舌回.左侧大脑半球激活体积明显大于右侧.结论 多个脑功能区参与维吾尔语义加工,fMRI能够很好地发现这些功能区,维吾尔族语言优势半球为左侧大脑半球.     

非流利型失语患者对汉语句子理解的句法和语义加工研究

目的利用汉语非流利型失语患者对汉语句子理解中句法和语义加工机制进行研究,来进一步探讨句子理解的理论,并为患者的语言康复治疗提供指导。方法选取2组被试为研究对象,即20例汉语非流利型失语患者(病例组)以及20例正常受试者(对照组),分别进行探测词是否为施事任务、"把"字句判断任务、语义可逆的句图匹配任务及短时记忆检测,比较2组受试者各项得分情况,分析两组被试表现上的差异。结果探测词是否为施事任务中病例组和对照组可逆osv词序、可逆svo词序之间有明显统计学差异(P0.05),而病例组和对照组不可逆osv词序、不可逆svo词序之间无明显统计学差异(P0.05)。失语患者在完成句子判断任务时句法违反和语义违反两种错误的判断的错误率无明显统计学差异(P0.05)。在句图匹配任务中失语患者对svo词序和"把"字句完成得较好,而对"被"字句和osv词序完成得较差,svo词序和"把"字句完成的错误率两者之间无明显统计学差异(P0.05),osv词序和"被"字句两者之间无明显统计学差异(P0.05);在短时记忆检测中病例组与对照组有明显统计学差异(P0.05)。结论 (1)非流利型失语患者出现了句法加工和语义加工的分离,实验支持句法自主理论;(2)支持句子的理解是一个可分离的阶段的理论。非流利型失语患者的句子理解障碍不能简单地归因于功能词加工障碍,句子理解障碍的原因可能是句法整合的障碍即句子理解的阶段三出现了障碍。     

抑郁症患者汉语情绪词阈下的Stroop效应事件相关电位

背景：抑郁症患者负性认知偏差与情绪信息加工的关系是一个重要的研究课题。情绪Stroop测验常用于评估情绪加工特点,而情绪词阈下Stroop刺激模式也常用于精神病学临床研究。 目的：本研究采用阈下汉语情绪词Stroop刺激范式来探讨抑郁症患者异常情绪信息加工的事件相关电位(ERP)效应。 设计,时间和地点：随机对照设计,时间为2007年8月至2008年3月,地点在中南大学湘雅二医院。 研究对象：首发抑郁症患者26例,符合DSM-IV抑郁症诊断标准,无脑部疾病、躯体疾病,未进行电休克治疗和抗抑郁药物治疗。健康对照组24例。两组在年龄、性别和教育水平方面无差异,均为右利手。 方法：采用阈下汉语情绪词Stroop刺激范式,要求被试对呈现200ms的红色或蓝色方块进行反应,而汉语情绪词阈下启动刺激为20ms。主要分析行为学和ERP数据。 主要测试指标：反应时和ERP成分的潜伏期和波幅。参照ERP平均波幅图以及其它研究,主要分析N270 (220~300ms)成分和N400 (380~450ms)成分的潜伏期和波幅。 结果：行为数据显示两组正确率之间无显著性差异,抑郁症组反应时比正常对照组延长,尤其是负性词与中性词(p<0.01)。重复测量方差分析表明,N270成分的波幅有词性和电极的主效应(p<0.01)以及词性和电极的交互效应(p<0.05);两组波幅大小顺序均为正性词>负性词>中性词。组别、词性差异波地形图显示差异主要分布在额区和左侧顶颞区。N400成分的波幅有词性和电极的主效应(p<0.01),潜伏期显示电极的主效应(p<0.01)以及电极和组别的交互效应(p<0.01);两组波幅大小顺序均为正性词>负性词>中性词,而且两组之间的三种情绪词波幅之间有显著性差异(p<0.01)。组别、词性差异波地形图显示差异主要分布在左右额区、中央区和左侧顶颞区。 结论：抑郁症患者执行阈下汉语情绪词Stroop刺激作业时表现了异常的情绪信息加工特征,以及对汉语情绪词三种词性进行语义激活时与正常组相比表现为不同的ERP时程效应。研究结果支持我们提出的正负性情绪平行神经模型。     

精神分裂症患者记忆围棋子位置时的脑激活区域

BACKGROUND： Go, a traditional Chinese chess-like game, requires many unknown functions of the brain including attention, imaging, problem solving and processing of spatial working memory. To date, it remains uncertain whether the intellectual activities required to play Go are related to the frontal lobe. OBJECTIVE： To investigate various patterns of brain region activity while schizophrenic patients and normal subjects engaged in memorizing piece placement in the Chinese game of Go. Spatial working memory was measured in order to validate whether the prefrontal lobe participates in this memory process.
DESIGN, TIME AND SETTING： Non-randomized, concurrent control trial was performed at Second Xiangya Hospital of Central South University, between May and December 2004.
PARTICIPANTS： A total of nine Chinese schizophrenic patients with no brain or bodily diseases and not undergoing electroshock treatment, who were in accordance with the DSM-Ⅳ criteria for schizophrenia, as well as thirteen healthy staffs and students with matched age, sex, and education were included. Patients and control subjects had no neurological disorders or mental retardation. In addition, all participants were right-handed. METHODS： The cognitive task for functional magnetic resonance imaging was a block design experiment. Both groups were asked to remember the placement of pieces in the Chinese game of Go on a computer screen. A brain activation map was analyzed in SPM99.
MAIN OUTCOME MEASURES： Brain responses were compared with regard to activation region size, volume, and asymmetry indices. RESULTS： Compared with the control group, the reaction time was significantly delayed in schizophrenics performing the working memory task （P 〈 0.05）. When performing the tasks, normal subjects showed significant activation of the bilateral dorsolateral prefrontal lobe with left dominance; the asymmetry indices were： frontal lobe, ＋0.32; temporal lobe, 0.58; parietal lobe, 0.41 ; and occipital lobe, 0.34. On the other hand, schizophrenics showed right dominance and had a broader activation region of the prefrontal lobe （asymmetry indices： frontal lobe, 0.10; temporal lobe, ＋0.38; parietal lobe, ＋0.24; and occipital lobe, 0.00）. When comparing the normal group subtracted with the schizophrenic group, no significant lateralization was found in the frontal lobes but significant activation was found in the left anterior central gyrus, left middle frontal gyrus and in both sides of the cingulate gyrus. Comparing the schizophrenic group subtracted with the normal group, there was significant right lateralization of the frontal lobe and abnormally activated regions on both sides of the anterior central gyrus, middle frontal gyrus, left inferior frontal gyrus, right medial frontal gyrus and the right insular lobe. CONCLUSION： Different brain activation regions are involved in memorizing the placement of pieces in Chinese Go between schizophrenia and healthy subjects. Schizophrenics showed right dominance and border activation range, indicating that the prefrontal cortex plays an important role in memory information processing and resource allocation when remembering piece placement in the game of Go.     

事件相关脑电位考察汉语句法和语义的加工机制

This study sought to test the processing of three types of sentences in Chinese, as correct sentences, semantic violation sentences, and sentences containing semantic and syntactic violations, based on the following sentence pattern: "subject (noun) + yi/gang/zheng + predicate (verb)". Event-related potentials on the scalp were recorded using 32-channel electroencephalography. Compared with correct sentences, target words elicited an early left anterior negativity (N400) and a later positivity (P600) over frontal, central and temporal sites in sentences involving semantic violations. In addition, when sentences contained both semantic and syntactic violations, the target words elicited a greater N400 and P600 distributed in posterior brain areas. These results indicate that Chinese sentence comprehension involves covert grammar processes.     

汉语语音加工的神经基础：图片刺激下的功能磁共振成像

对语音加工的研究使用文字刺激的较多。实验采用fMRI技术,使用图片刺激,在汉语押韵任务下,考察与汉语语音加工相关的脑区。对13名以汉语为母语的在校健康本科大学生的测试结果显示：图片刺激下汉语的语音加工会激活额叶、顶叶和枕颞联合皮质,包括额下回、额中回、缘上回、枕颞内侧回等。此外,图片刺激下汉语语音加工在颞上回BA22区引起了激活,但在颞中回未出现激活。     

精神分裂症言语流畅性任务期间脑激活的纵向近红外光谱成像研究

目的 基于近红外光谱成像（near-infrared spectroscopy,NIRS）技术,探索精神分裂症患者言语流畅性任务下的脑激活情况是否会随着治疗进程发生改变,分析NIRS是否具有评估患者精神症状改善程度的价值。方法 纳入53例精神分裂症患者和55名健康对照。入组时使用NIRS检测所有被试言语流畅性任务期间额颞叶9个感兴趣区域（region of interest,ROI）的氧合血红蛋白（oxygenated hemoglobin,oxy-Hb）变化情况,使用阳性与阴性症状量表（positive and negative symptom scale,PANSS）评估患者症状的严重程度。患者以单一非典型抗精神病药物治疗,4周后对患者再次进行PANSS评定和NIRS检测。结果 入组时,与基线值相比,患者组9个ROI均未激活（P>0.05,FDR校正）,对照组均激活（P<0.05,FDR校正）,患者组ROI的oxy-Hb变化值均低于对照组（P<0.05,FDR校正）。4周后患者组PANSS总分、各分量表评分均较入组时下降（P<0.05）,有6个ROI激活（P...     

情绪词汇认知加工诱发电位时空模式的脑功能研究

目的应用多通道事件相关电位(event-related potential,ERP)分析技术,探讨正常青年受试者对情绪性词汇认知加工脑神经功能电活动机制。方法应用不同情绪效价的情绪刺激图片对31例健康志愿者进行情绪效价5个水平情绪脑电诱发电位的测试判别,观察受试者对5个情绪效价水平情绪词汇的情绪反应。结果 ERPs统计参数映像图(SPM)结果,对词汇情绪性加工的显著性差异最早可见于刺激后60~200ms;中后期(刺激后420~960ms)极负性和中性情绪反应显著性差异表现为右腹侧记忆-注意整合网络出现刺激负荷效应。极正性和中性情绪反应差异为中期(刺激后320~420ms)的左顶、颞、枕,晚期(刺激后680~1 000ms)见到右额中央负荷效应。极正性和极负性情绪反应差异于刺激后400~1 000ms见于双侧眶额皮层、腹内侧前额皮层、前扣带回皮层和躯体感觉皮层等脑区的广泛记忆-注意整合网络引起更强的激活。结论个体认知行为差异和社会环境背景影响不同情绪效价情绪性词汇的加工,不同情绪效价的情绪性词汇加工过程中存在显著性差异。正负性情绪词汇的加工是双侧半球广泛脑区的记忆-注意整合网络激活效应,并存在脑的偏侧化激活效应。     

Specialization of phonological and semantic processing in Chinese word reading

The purpose of this study was to examine the neurocognitive network for processing visual word forms in native Chinese speakers using functional magnetic resonance imaging (fMRI). In order to compare the processing of phonological and semantic representations, we developed parallel rhyming and meaning association judgment tasks that required explicit access and manipulation of these representations. Subjects showed activation in left inferior/middle frontal gyri, bilateral medial frontal gyri, bilateral middle occipital/fusiform gyri, and bilateral cerebella for both the rhyming and meaning tasks. A direct comparison of the tasks revealed that the rhyming task showed more activation in the posterior dorsal region of the inferior/middle frontal gyrus (BA 9/44) and in the inferior parietal lobule (BA 40). The meaning task showed more activation in the anterior ventral region of the inferior/middle frontal gyrus (BA 47) and in the superior/middle temporal gyrus (BA 22,21). These findings are consistent with previous studies in English that suggest specialization of inferior frontal regions for the access and manipulation of phonological vs. semantic representations, but also suggest that this specialization extends to the middle frontal gyrus for Chinese. These findings are also consistent with the suggestion that the left middle temporal gyrus is involved in representing semantic information and the left inferior parietal lobule is involved in mapping between orthographic and phonological representations.     

Developmental differences of neurocognitive networks for phonological and semantic processing in Chinese word reading

Developmental differences in the neurocognitive networks for phonological and semantic processing in Chinese word reading were examined in 13 adults and 13 children using functional magnetic resonance imaging (fMRI). Rhyming and semantic association judgments were made to two-character words that were presented sequentially in the visual modality. These lexical tasks were compared with a nonlinguistic control task involving judgment of line patterns. The first main finding was that adults showed greater activation than children in right middle occipital gyrus on both the meaning and rhyming task, suggesting adults more effectively engage right hemisphere brain regions involved in the visual-spatial analysis of Chinese characters. The second main finding was that adults showed greater activation than children in left inferior parietal lobule for the rhyming as compared with the meaning task, suggesting greater specialization of phonological processing in adults. The third main finding was that children who had better performance in the rhyming task on characters with conflicting orthographic and phonological information relative to characters with nonconflicting information showed greater activation in left middle frontal gyrus, suggesting greater engagement of brain regions involved in the integration of orthography and phonology.     

Similar alterations in brain function for phonological and semantic processing to visual characters in Chinese dyslexia

Dyslexia in alphabetic languages has been extensively investigated and suggests a central deficit in orthography to phonology mapping in the left hemisphere. Compared to dyslexia in alphabetic languages, the central deficit for Chinese dyslexia is still unclear. Because of the logographic nature of Chinese characters, some have suggested that Chinese dyslexia should have larger deficits in the semantic system. To investigate this, Chinese children with reading disability (RD) were compared to typically developing (TD) children using functional magnetic resonance imaging (fMRI) on a rhyming judgment task and on a semantic association judgment task. RD children showed less activation for both tasks in right visual (BA18, 19) and left occipito-temporal cortex (BA 37), suggesting a deficit in visuo-orthographic processing. RD children also showed less activation for both tasks in left inferior frontal gyrus (BA44), which additionally showed significant correlations with activation of bilateral visuo-orthographic regions in the RD group, suggesting that the abnormalities in frontal cortex and in posterior visuo-orthographic regions may reflect a deficit in the connection between brain regions. Analyses failed to reveal larger differences between groups for the semantic compared to the rhyming task, suggesting that Chinese dyslexia is similarly impaired in the access to phonology and to semantics from the visual orthography.     

Neural representation of phonological information during Chinese character reading

Previous studies have revealed that phonological processing of Chinese characters elicited activation in the left prefrontal cortex, bilateral parietal cortex, and occipitotemporal regions. However, it is controversial what role the left middle frontal gyrus plays in Chinese character reading, and whether the core regions (e.g., the left superior temporal gyrus and supramarginal gyrus) for phonological processing of alphabetic languages are also involved in Chinese character reading. To address these questions, the present study used both univariate and multivariate analysis (i.e., representational similarity analysis, RSA) to explore neural representations of phonological information during Chinese character reading. Participants were scanned while performing a reading aloud task. Univariate activation analysis revealed a widely distributed network for word reading, including the bilateral inferior frontal gyrus, middle frontal gyrus, lateral temporal cortex, and occipitotemporal cortex. More importantly, RSA showed that the left prefrontal (i.e., the left middle frontal gyrus and left inferior frontal gyrus) and bilateral occipitotemporal areas (i.e., the left inferior and middle temporal gyrus and bilateral fusiform gyrus) represented phonological information of Chinese characters. These results confirmed the importance of the left middle frontal gyrus and regions in ventral pathway in representing phonological information of Chinese characters.     

Functional connectivity during orthographic,phonological, and semantic processing of Chinese characters identifies distinct visuospatial and phonosemantic networks

While neuroimaging studies have identified brain regions associated with single word reading, its three constituents, namely, orthography, phonology, and meaning, and the functional connectivity of their networks remain underexplored. This study examined the neurocognitive underpinnings of these neural activations and functional connectivity of the identified brain regions using a within‐subject design. Thirty‐one native Mandarin speakers performed orthographic, phonological, and semantic judgment tasks during functional magnetic resonance imaging. The results indicated that the three processes shared a core network consisting of a large region in the left prefrontal cortex, fusiform gyrus, and medial superior frontal gyrus but not the superior temporal gyrus. Orthographic processing more strongly recruited the left dorsolateral prefrontal cortex, left superior parietal lobule and bilateral fusiform gyri; semantic processing more strongly recruited the left inferior frontal gyrus and left middle temporal gyrus, whereas phonological processing more strongly activated the dorsal part of the precentral gyrus. Functional connectivity analysis identified a posterior visuospatial network and a frontal phonosemantic network interfaced by the left middle frontal gyrus. We conclude that reading Chinese recruits cognitive resources that correspond to basic task demands with unique features best explained in connection with the individual reading subprocesses.     

Separating phonological and semantic processing in auditory sentence processing: a high-resolution event-related brain potential study

Phonological and semantic processing was studied using high-resolution event-related brain potentials (ERPs) during a sentence-matching task to investigate the spatial distribution of the phonological mismatch negativity (PMN) and the N400 response. It was hypothesized that the two components were spatially separable and that the activity matched prior localization knowledge. Participants examined visual-auditory sentence pairs that related within a semantic hierarchy (e.g., visual: "The man is teaching in the classroom"; Auditory: "The man is in the em leader school/barn"). Semantic congruency was varied for the final words of the spoken sentences. Incongruent words mismatched expectation in terms of both the initial phonological features (unexpected sound) and semantic features (unexpected meaning). In addition, the category-exemplar probability of the final words was either high or low, with low probability words being more difficult to anticipate. Low probability words were predicted to selectively affect PMN activity. We found that incongruent words elicited a PMN (287 msec) and a N400 (424 msec), for both the high and low probability words. As expected, low probability congruent words elicited a small PMN but no N400. In contrast, high probability congruent words elicited neither a detectible PMN nor a N400. The primary PMN sources were in left inferior frontal and inferior parietal lobes. The primary N400 source activation occurred along the left perisylvian cortex, consistent with prior N400 source localization work. From these results, it was concluded that the PMN and N400 were localized to separate cortical language (and memory) regions and had different source activation patterns.     

Brain potentials during semantic and prosodic processing in French

The present experiment was aimed at investigating the on-line processing of semantic and prosodic information. We recorded the Event-Related brain Potentials (ERPs) to semantically and/or prosodically congruous and incongruous sentences that were presented aurally, to study the time course of semantic and prosodic processing, and to determine whether these two processes are independent or interactive. The prosodic mismatch was produced by cross-splicing the beginning of statements with the end of questions, and vice-versa. Subjects had to decide whether the sentences were semantically or prosodically congruous in two different attention conditions. Results showed that a right centro-parietal negative component (N400) was associated with semantic mismatch, and a left temporo-parietal positive component (P800) was associated with prosodic mismatch. Thus, these two electrophysiological markers of semantic and prosodic processing differed in their polarity, latency and scalp distribution. These differences may indicate that the two processes stem from different underlying generators. However, the finding that the P800 elicited by prosodic mismatch was larger when the sentences were semantically incongruous than congruous suggests that the two processes may be interactive.     

Implicit phonological and semantic processing in children with developmental dyslexia: Evidence from event-related potentials

Dyslexia is characterized by a core phonological deficit, although recent studies indicate that semantic impairment also contributes to this condition. In this study, event-related potentials (ERP) were used to examine whether the N400 wave in dyslexic children is modulated by phonological or semantic priming, similarly to age-matched controls. ERPs were recorded while children listened to word lists in which the semantic and phonological congruency of the terminal words were manipulated. No overt judgments were made by participants. In control children the N400 amplitude to both semantically and phonologically incongruent words was enlarged relative to congruent words. Dyslexic children exhibited a dissociation of priming effects depending on whether semantic or phonological primes were used. Semantic priming elicited an N400 effect comparable to controls, though delayed. In phonological priming, the dyslexics differed from controls in both the phonologically incongruent and congruent conditions showing reduced N400 amplitude in the former and enhanced N400 in the latter. This pattern suggests that when faced with phonological priming, dyslexics show abnormal neural responses related to both integration of similarities between the consecutive stimuli and the ability to detect incongruent stimuli. Semantic priming seems relatively intact in dyslexics, however neural responses to contextual incongruency are delayed.     

Understanding semantic and phonological processing deficits in adults with aphasia: effects of category and typicality

Background: Semantic and phonological processing deficits are often present in aphasia. The degree of interdependence between the deficits has been widely studied with variable findings. Semantic variables such as category and typicality have been found to influence semantic processing in healthy individuals and persons with aphasia (PWA), but their influence on phonological processing is unknown.

Aims: This study examined the nature of semantic and phonological access in aphasia by comparing adults with aphasia to healthy control participants. Semantic and phonological tasks were used to assess the difference in processing requirements between and within each group as well as examine the effects of category and typicality on different stages of semantic and phonological processing.

Methods & Procedures: Thirty-two PWA and 10 neurologically healthy adults were administered nine tasks: Category Superordinate, Category Coordinate, Semantic Feature, Rhyme Judgment (No-Name), Syllable Judgment (No-Name), Phoneme Verification (No-Name), Rhyme Judgment (Name-Provided), Syllable Judgment (Name-Provided), and Phoneme Verification (Name-Provided). Accuracy and reaction time (RT) data were collected for each of these tasks and between-group and within-group differences were analysed via MANOVA/MANCOVA and hierarchical clustering analyses.

Outcomes & Results: PWA performed with significantly lower accuracy than controls on phonological tasks but performed comparably on semantic tasks. Participants with aphasia were significantly slower than controls on all semantic and phonological tasks. Clustering of the nine tasks by accuracy revealed different processing requirements in the participants with aphasia compared to the control group while clustering by RT revealed similar trends in both groups in that phonological (no-name) items required the most processing time. Significant effects of category and typicality were noted in the semantic tasks but not in any of the phonological tasks.

Conclusions: Individuals with aphasia demonstrated overall impaired phonological processing with relatively preserved semantic processing as compared to controls. Per accuracy and RT measures, distinct trends in processing load for semantic tasks versus phonological tasks were seen in the individuals with aphasia whereas only speed of processing and not accuracy was impacted by phonological processing load in the control group. The results align most closely with discrete serial processing models of lexical processing as category and typicality effects were robust in the semantic tasks but not in any of the phonological tasks. Alternative explanations for these results also are discussed.