新颖语义联结在顿悟促进记忆效果中的作用

采用成语谜题选择任务, 通过学习-测验范式探究顿悟促进记忆的认知神经机制。实验1采用行为实验, 验证成语谜题选择范式在探究顿悟促进记忆中的有效性, 结果显示, 相比于寻常联结条件, 新颖联结条件下被试在学习阶段具有更高的顿悟感得分, 在测试阶段具有更高的正确率, 范式的有效性得以验证。实验2采用fMRI技术探究顿悟促进记忆的关键脑区。结果显示, 相比于失败记忆新颖联结条件, 成功记忆新颖联结条件更强地激活了顿悟过程相关脑区, 包括海马、杏仁核、额中回、颞上回和颞中回。这说明在学习阶段的顿悟问题解决过程中, 对信息的深加工与积极情绪促进了随后的记忆; 对其进一步分析发现, 相比于寻常联结记忆, 新颖联结对记忆的促进效应主要与右侧海马激活有关, 它可能反映了在顿悟问题解决中新颖联结形成过程建立了情节记忆以及新颖且有价值的语义联结。研究结果表明新颖语义联结形成在顿悟促进记忆中发挥了重要作用。     

抑郁症情绪加工与认知控制的脑机制

抑郁症患者负性认知加工偏向是导致抑郁的一个主要认知因素, 是抑郁症的一个稳定特质。这种偏向与对负性情绪刺激自下而上的情绪加工增强有关, 表现为杏仁核和梭状回等脑区过度激活; 也与自上而下的认知控制功能不足有关, 表现为背外侧前额皮质、前扣带回等脑区活性不足。文章在前人研究基础上, 提出了关于抑郁症情绪加工与认知控制脑机制的一个理论假说, 即抑郁症的产生是由于抑郁症患者情绪加工脑区过度激活与认知控制脑区功能降低之间的相互作用而形成的恶性循环所介导。目前证明此理论假说在研究内容、研究材料、研究技术等方面还存在一些问题, 这些可能是未来研究的方向。     

记忆汉字和英语单词的差异脑区研究

通过英文词和汉字的记忆实验,探讨储存和提取不同阶段汉字与英文的脑加工差异。采用经典的"学习-再认"实验范式,8名大学生进行英文与汉字记忆和再认测验,fMRI采集数据,AFNI软件进行预处理、多元回归及ANOVA组分析统计语言差异。结果显示:汉字记忆减英文记忆激活右扣带回;英文记忆减汉字记忆激活右颞上回(BA38)、左扣带回(BA31)、左小脑扁桃体。汉字再认减英文再认的差异脑区为小脑扁桃体、左颞上回。英文再认减汉字再认在0.05水平上没有脑区差异。汉字记忆激活左侧梭状回、右舌回、左顶上小叶、左额下回;英文记忆激活右舌回、左内侧前额叶、左中央前回、左额中回。汉字再认激活左枕下回、左顶下小叶、右额下回、左额中回、右豆状核、左小脑扁桃体、左颞上回、右内侧前额叶。英文再认激活右舌回、左额上回、左顶下小叶、额下回、左中央前回、右顶上小叶、豆状核、右侧尾状核、左中央后回、左侧丘脑。本研究发现:(1)记忆的差异性统计激活颞叶,表明颞叶是记忆存储脑区;(2)学习和记忆阶段有额叶、顶叶激活,表明这些脑区参与文字加工;(3)英文再认比汉字再认激活更多脑区,花费更多的脑资源。     

认知重评和表达抑制情绪调节策略的脑网络分析：来自EEG和ERP的证据

本文旨在对认知重评和表达抑制两种常用情绪调节策略的自发脑网络特征及认知神经活动进行深入探讨。研究采集36名在校大学生的静息态和任务态脑电数据, 经过源定位和图论分析发现节点效率与两种情绪调节显著相关的脑区, 以及脑区之间的功能连接。研究结果表明, 在使用认知重评进行情绪调节时会激活前额叶皮质、前扣带回、顶叶、海马旁回和枕叶等多个脑区, 在使用表达抑制进行情绪调节时会激活前额叶皮质、顶叶、海马旁回、枕叶、颞叶和脑岛等多个脑区。因此, 这些脑区的节点效率或功能连接强度可能成为评估个体使用认知重评和表达抑制调节情绪效果的指标。     

内隐记忆与外显记忆的神经过程研究

在认知神经科学中,内隐记忆与外显记忆的神经过程研究倍受关注.本文对记忆编码和提取的脑功能成像研究成果,以及提取过程中内隐与外显记忆所激活的相关脑区特征进行了较为详尽的分析.最后对有关记忆研究领域的未来发展作出展望.     

时间延迟对故事情境关联虚假记忆的影响

研究以故事情境短文为实验材料,探讨了即时与延时48h后虚假记忆变化表现及其与真实记忆相分离的认知神经机制。结果表明,虚假记忆在延迟48h后诱发的LPC走向比即时更正性;即时条件虚假记忆与真实记忆认知加工相分离表现在有意回想加工及额叶后提取加工阶段,延迟48h后仅表现在额叶后提取加工阶段。上述结果为虚假记忆存在随时间变化及其与真实记忆相分离提供了电生理证据。     

读写分离的脑神经机制：来自fMRI的证据

使用只读不写的繁体字和会读会写的简体字材料, 以默读为实验任务, 探讨“会读会写”与“只读不写”文字的加工脑区。8名在校大学生在磁共振扫描过程中默读呈现的繁体字或简体字, 采用ANOVA统计全脑激活图。与简体字相比, 繁体字额外激活了右额下回、左小脑。在功能连接性上, 简体字和繁体字相同的激活脑区有左楔前叶-左内侧前额叶, 左楔前叶-左中央前回, 右枕中回-左舌回; 不同的是, 繁体字左楔前叶与右额下回有高相关, 而简体字左楔前叶与右额中回有高相关。左内侧前额叶与中央前回只在繁体字中表现出高相关。繁体字和简体字任务的T检验差异脑区包括左颞中回和右顶下小叶。只读不写的文字具有加工的整体性和轮廓性特征, 它的读音与不规则简体字相似, 具有整字加工特点。繁体字和简体字加工具有相同的功能连接区, 但也存在差异。右脑表现为连接脑区不同, 左脑内侧前额叶与中央前回表现为相关性不同, 说明内侧前额叶-中央前回在繁体字加工中起着重要作用。实验结果还证明顶叶是记忆再认的主要脑区。     

左侧角回在词汇语义加工中的作用

大脑左侧角回是语言认知神经科学研究发现的一个重要语义加工脑区。该脑区在词汇语义加工中的具体功能还没有得到统一的认识,成为研究者广泛关注的热点和焦点问题。结构上,角回位于颞叶、枕叶和顶叶交接区,并且具有广泛的白质纤维束连接,这决定了它可能具有跨区域信息整合的功能。它在高水平语义表征、模态和特征信息联合表征、语义关系表征以及语义整合加工中参与激活,可能是语义表征和加工的信息“聚合区”。然而,左侧角回在语义表征枢纽、语义执行控制加工、默认模式网络的语义加工三方面还存在功能争论,未来研究需要综合考虑左侧角回的解剖结构基础及其与广泛脑区连接的特点,对角回子区域的功能进行深入细致地探讨。     

认知判断中手部动作模拟的fMRI研究

该研究采用功能磁共振成像技术,考察不同条件下进行工具认知判断时手部姿势对认知判断的影响及动作模拟的神经机制。实验发现：手部姿势存在显著的主效应,冲突手部姿势条件下反应时最慢,且冲突手部姿势条件下与不冲突手部姿势条件下、自然状态条件下反应时存在显著差异,自然状态条件与不冲突手部姿势条件下反应时不存在显著差异。另外,f MRI成像结果发现,额中回、额下回、顶下小叶以及辅助运动区在自然状态下有显著激活,表明个体在进行认知判断过程中有动作模拟过程;海马结构、扣带回及楔前叶等与记忆有关的脑区有显著激活,表明身体经验在认知过程的作用。总的研究表明,不同的手部姿势状态对认知判断有不同影响,冲突手部姿势会对动作模拟产生干扰作用,手部动作模拟的神经机制主要涉及镜像神经元区,且在认知判断时存在具身效应。     

科学发明情境中问题提出的fMRI研究

本研究中, 以76个科学发明问题(36个带有相关的原型, 40个不带有相关的原型)为实验材料,使用功能性磁共振成像(fMRI)技术探讨了科学发明情境中的问题提出以及新近获得的语义对有价值的科学问题提出的启发效应的大脑机制。对有原型提出有价值的科学问题与无原型提出一般问题这两种情况下被试反应的数据进行记录和分析。结果表明两种情况下共同激活的脑区(科学发明情境中问题提出的脑区)为左侧梭状回、左侧内侧额叶、左侧豆状核、右小脑和左侧中央前回。这些共同激活的脑区表明：左侧梭状回也许与各个语句的语义表征有关; 左侧内侧额叶也许与所有语句的整体语义表征以及提出各个语义之间的“问题”有关(左侧豆状核和右小脑配合内侧额叶分别负责控制注意、眼动的指向和注意资源的分配); 左侧中央前回可能负责用语句表述出所提出的语义之间的“问题”。对有原型提出有价值的科学问题和无原型提出有价值的科学问题这两种情况下被试反应的数据进行记录和分析。结果表明有原型提出有价值的科学问题比无原型提出有价值的科学问题显著激活的脑区(科学发明情境中新近获得的语义对有价值的科学问题提出的启发效应的脑区)为左侧楔前叶、左侧额下回、左侧颞中回。这些显著激活的脑区表明：楔前叶与情境记忆的贮存和提取有关; 额中回与认知控制和注意资源的分配有关; 颞中回与新异性原型的成功激活有关。     

Regulation of brain activity in the fusiform face and parahippocampal place areas in 7–11-year-old children

Developmental studies have demonstrated that cognitive processes such as attention, suppression of interference and memory develop throughout childhood and adolescence. However, little is currently known about the development of top-down control mechanisms and their influence on cognitive performance. In the present study, we used functional magnetic resonance imaging to investigate modulation of activity in the ventral visual cortex in healthy 7–11-year-old children and young adults. The participants performed tasks that required attention to either face (Fs task) or scene (Sf task) images while trying to ignore distracting scene or face images, respectively. A face-selective area in the fusiform gyrus (fusiform face area, FFA) and an area responding preferentially to scene images in the parahippocampal gyrus (parahippocampal place area, PPA) were defined using functional localizers. Children responded slower and less accurately in the tasks than adults. In children, the right FFA was less selective to face images and regulation of activity between the Fs and Sf tasks was weaker compared to adults. In the PPA, selectivity to scenes and regulation of activity, there according to the task demands were comparable between children and adults. During the tasks, children activated prefrontal cortical areas including the middle (MFG) and superior (SFG) frontal gyrus more than adults. Functional connectivity between the right FFA and left MFG was stronger in adults than children in the Fs task. Children, on the other hand, had stronger functional connectivity than adults in the Sf task between the right FFA and right PPA and between right MFG and medial SFG. There were no group differences in the functional connectivity between the PPA and the prefrontal cortex (PFC). Together the results suggest that, in 7–11-year-old children, the FFA is still immature, whereas the selectivity to scenes and regulation of activity in the PPA is comparable to adults. The results also indicated functional immaturity of the PFC in children compared to adults and weaker connectivity between the PFC and the rFFA, explaining the weaker regulation of activity in the rFFA between the Fs and Sf tasks.     

Neuro-cognitive aspects of “OM” sound/syllable perception: A functional neuroimaging study

The sound “OM” is believed to bring mental peace and calm. The cortical activation associated with listening to sound “OM” in contrast to similar non-meaningful sound (TOM) and listening to a meaningful Hindi word (AAM) has been investigated using functional magnetic resonance imaging (MRI). The behaviour interleaved gradient technique was employed in order to avoid interference of scanner noise. The results reveal that listening to “OM” sound in contrast to the meaningful Hindi word condition activates areas of bilateral cerebellum, left middle frontal gyrus (dorsolateral middle frontal/BA 9), right precuneus (BA 5) and right supramarginal gyrus (SMG). Listening to “OM” sound in contrast to “non-meaningful” sound condition leads to cortical activation in bilateral middle frontal (BA9), right middle temporal (BA37), right angular gyrus (BA 40), right SMG and right superior middle frontal gyrus (BA 8). The conjunction analysis reveals that the common neural regions activated in listening to “OM” sound during both conditions are middle frontal (left dorsolateral middle frontal cortex) and right SMG. The results correspond to the fact that listening to “OM” sound recruits neural systems implicated in emotional empathy.     

The neural basis of autobiographical and semantic memory: new evidence from three PET studies

A novel, neuropsychologically informed paradigm (extended retrieval of events in response to a cue word) was used to investigate the neural basis of autobiographical and semantic memory. Contrasting retrieval of autobiographical memories with retrieval of semantic facts (ABM-SEM) in 24 subjects across three PET studies revealed bilateral involvement of the middle temporal gyrus (BA 21) and medial frontal cortex (BA 9/10). The opposite contrast, SEM-ABM, resulted in increased regional cerebral blood flow in left posterior temporal regions (BA 37) and left prefrontal cortex (BA 45/46). Laterality maps suggest that the bilateral pattern seen in our studies, but not often in other neuroimaging investigations, reflects the use of a task stressing retrieval of specific personal events. Further comparisons revealed that the activation in the right anterior temporal lobe during autobiographical recall was virtually identical to that seen during retrieval of information about famous people or events in contrast with retrieval of general semantic facts. These findings suggest that the retrieval of an autobiographical event requires participation from conceptual knowledge, and that this type of knowledge is bilaterally distributed in the temporal lobes.     

文盲与非文盲汉字字形和语音加工的脑机制

利用功能性磁共振成像(fMRI)技术探讨文盲和非文盲汉字字形和语音加工脑机制的差异。实验1使用汉字字形和图形比较了中国人文盲和非文盲字形加工过程脑机制的左侧差异。实验2使用汉字语音和纯音比较了文盲和非文盲语音加工过程脑机制的双侧差异。结果表明文盲与非文盲汉字字形和语音加工脑机制不同,且非文盲的脑活动强。     

Neural correlates of subliminal and supraliminal letter processing--an event-related fMRI study

One problem of interpreting research on subconscious processing is the possibility that participants are weakly conscious of the stimuli. Here, we compared the fMRI BOLD response in healthy adults to clearly visible single letters (supraliminal presentation) with the response to letters presented in the absence of any behavioural evidence of visibility (subliminal presentation). No letter catch trials served as a control condition. Forced-choice responses did not differ from chance when letter-to-background contrast was low, whereas they were almost 100% correct when contrast was high. A comparison of fMRI BOLD signals for supraliminal and subliminal letters with the control trials revealed a signal increase in left BA 37 (fusiform gyrus). Comparison of supraliminal with subliminal letters showed a significant increase in the right inferior frontal gyrus (BA 44, partly extending to BA 9 and BA 45, as well as BA 46). Finally, a comparison of subliminal with supraliminal letters showed increases in the left middle temporal gyrus (BA 21) and the right extrastriate cortex (BA 19).     

Direct comparison of episodic encoding and retrieval of words: an event-related fMRI study

Functional magnetic resonance imaging (fMRI) was used to compare directly episodic encoding and retrieval. During encoding, subjects studied visually presented words and reported via keypress whether each word represented a pleasant or unpleasant concept (intentional, deep encoding). During the retrieval phase, subjects indicated (via keypress) whether visually presented words had previously been studied. No reliable differences were found during the recognition phase for words that had been previously studied and those that had not been studied. Areas preferentially active during encoding (relative to retrieval) included left superior frontal cortex, medial frontal cortex, left superior temporal cortex, posterior cingulate, left parahippocampal gyrus, and left inferior frontal gyrus. Regions more active in retrieval than encoding included bilateral inferior parietal cortex, bilateral precuneus, right frontal polar cortex, right dorsolateral prefrontal cortex, and right inferior frontal/insular cortex.     

Direct Comparison of Episodic Encoding and Retrieval of Words: An Event-related fMRI Study

Functional magnetic resonance imaging (fMRI) was used to compare directly episodic encoding and retrieval. During encoding, subjects studied visually presented words and reported via keypress whether each word represented a pleasant or unpleasant concept (intentional, deep encoding). During the retrieval phase, subjects indicated (via keypress) whether visually presented words had previously been studied. No reliable differences were found during the recognition phase for words that had been previously studied and those that had not been studied. Areas preferentially active during encoding (relative to retrieval) included left superior frontal cortex, medial frontal cortex, left superior temporal cortex, posterior cingulate, left parahippocampal gyrus, and left inferior frontal gyrus. Regions more active in retrieval than encoding included bilateral inferior parietal cortex, bilateral precuneus, right frontal polar cortex, right dorsolateral prefrontal cortex, and right inferior frontal/insular cortex.     

Effective brain connectivity in children with reading difficulties during phonological processing

Using Dynamic Causal Modeling (DCM) and functional magnetic resonance imaging (fMRI), we examined effective connectivity between three left hemisphere brain regions (inferior frontal gyrus, inferior parietal lobule, fusiform gyrus) and bilateral medial frontal gyrus in 12 children with reading difficulties (M age=12.4, range: 8.11-14.10) and 12 control children (M age=12.3, range: 8.9-14.11) during rhyming judgments to visually presented words. More difficult conflicting trials either had similar orthography but different phonology (e.g. pint-mint) or similar phonology but different orthography (e.g. jazz-has). Easier non-conflicting trials had similar orthography and phonology (e.g. dime-lime) or different orthography and phonology (e.g. staff-gain). The modulatory effect from left fusiform gyrus to left inferior parietal lobule was stronger in controls than in children with reading difficulties only for conflicting trials. Modulatory effects from left fusiform gyrus and left inferior parietal lobule to left inferior frontal gyrus were stronger for conflicting trials than for non-conflicting trials only in control children but not in children with reading difficulties. Modulatory effects from left inferior frontal gyrus to inferior parietal lobule, from medial frontal gyrus to left inferior parietal lobule, and from left inferior parietal lobule to medial frontal gyrus were positively correlated with reading skill only in control children. These findings suggest that children with reading difficulties have deficits in integrating orthography and phonology utilizing left inferior parietal lobule, and in engaging phonological rehearsal/segmentation utilizing left inferior frontal gyrus possibly through the indirect pathway connecting posterior to anterior language processing regions, especially when the orthographic and phonological information is conflicting.     

Association of Fine Motor Loss and Allodynia in Fibromyalgia: An fNIRS Study

Recent studies showed that fine motor control dysfunction was observed in fibromyalgia (FM) syndrome as well as allodynia. However, brain signatures of this association still remain unclear. In this study, finger tapping task (FTT) and median nerve stimulation (MNS) were applied to both hands of 15 FM patients and healthy controls (HC) to understand this relationship. Hemodynamic activity was measured simultaneously using functional near-infrared spectroscopy (fNIRS). Experiments were analyzed separately by using 2x2 repeated measures ANOVA. Results for the FTT experiment revealed that HC showed higher activity than FM patients in bilateral superior parietal gyrus (SPG), left supramarginal gyrus (SMG) and right somatosensory cortex (SI). Furthermore, right-hand FTT resulted in higher activity than left-hand FTT in left SPG, left SI and right motor cortex (MI). In the MNS experiment, FM patients showed higher activity than HC in bilateral SPG, right SMG, right SI and right middle frontal gyrus (MFG). Negative correlation was observed in left SPG between FTT and MNS activities. Besides, MNS activity in left SPG was negatively correlated with left-hand pain threshold.This study revealed that left SPG might be an important indicator to associate fine motor loss and allodynia in FM.     

Individual Differences in Brain Structure and Resting Brain Function Underlie Representation-Connection in Scientific Problem Solving

Evidence from a range of fields shows that representation-connection (RC) is the key step towards the solution of a real-world insight problem. However, no study has focused on the inter-individual variability in RC, and little is known about whether structural and resting-state functional signals can account for inter-individual differences in RC. Combining structural (regional grey matter density, rGMD) and functional (fractional amplitude of low-frequency fluctuations (fALFF) and resting-state functional connectivity (RSFC)) analysis approaches was used to examine the neural substrates of RC. The results showed that the RC score was positively correlated with rGMD and fALFF values in the bilateral lingual gyrus (LG), which might be related to relevant visual imagery during the correct matching of a specific prototype with an unsolved technical problem and the retrieval and application of key information from prototypes. In addition, the RC score was negatively correlated with the rGMD in the left dorsolateral prefrontal cortex (DLPFC), and functional connectivity analysis revealed that a higher RC score was inversely correlated with the strength of the RSFC between the right LG and the left inferior parietal lobule (IPL), which indicated that RC might be supported by decreased response inhibition and the automatic association of semantics.