Advances in the field of quantum sensing mean that magnetic field sensors, operating at room temperature, are now able to achieve sensitivity similar to that of cryogenically cooled devices (SQUIDs). This means that room temperature magnetoencephalography (MEG), with a greatly increased flexibility of sensor placement can now be considered. Further, these new sensors can be placed directly on the scalp surface giving, theoretically, a large increase in the magnitude of the measured signal. Here, we present recordings made using a single optically-pumped magnetometer (OPM) in combination with a 3D-printed head-cast designed to accurately locate and orient the sensor relative to brain anatomy. Since our OPM is configured as a magnetometer it is highly sensitive to environmental interference. However, we show that this problem can be ameliorated via the use of simultaneous reference sensor recordings. Using median nerve stimulation, we show that the OPM can detect both evoked (phase-locked) and induced (non-phase-locked oscillatory) changes when placed over sensory cortex, with signals ~4 times larger than equivalent SQUID measurements. Using source modelling, we show that our system allows localisation of the evoked response to somatosensory cortex. Further, source-space modelling shows that, with 13 sequential OPM measurements, source-space signal-to-noise ratio (SNR) is comparable to that from a 271-channel SQUID system. Our results highlight the opportunity presented by OPMs to generate uncooled, potentially low-cost, high SNR MEG systems.Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

脑磁图作为一种无创的脑功能成像技术，依靠超高的时间及空间溯源分辨率，在脑科学研究和临床应用领域中有着极其重要的价值.本文介绍了自主搭建的基于原子磁力计的穿戴式脑磁图系统，通过设计匀场补偿线圈组并结合参考传感器阵列，实现被试头部运动区域内剩磁在±1 nT以内，保证动态测量过程中传感器输出维持在动态范围以内；同时提出了一种虚拟合成梯度去噪方法，显著抑制了环境共模噪声；最终在被试者头部自然运动状态下，成功检测到高信噪比的α节律信号与听觉诱发磁场信号，证实了该系统的有效性，为穿戴式脑磁图应用推广提供更多的可能性.

该文以超导量子干涉元件研究光激发氦三极化气体的低磁场磁共振与造影术. 使用圆偏极化雷色光将氦三气体极化, 超导量子干涉元件磁共振与造影之测量是以磁通耦合方式来进行, 超导量子干涉元件是用铋锶钙铜氧高溫超导罐来隔离环境噪音. 此方法测得的磁共振信号与影像相较于直接将样品置于杜瓦瓶下方有较高的信噪比, 当样品无法靠近感测元件时, 此装置具高信噪比特色. 磁通耦合方式的超导量子干涉元件低磁场磁共振与造影术及其氦三极化气体的肺部造影在学术与应用上是相当有趣.

目的 探索基于汉语高频名词的词图匹配语义判断任务的设计思路,以及该任务下的功能磁共振成像(fMRI)和事件相关电位(ERP)实验研究方法,为该领域研究提供范式。方法 阐述汉语高频名词的词图匹配判断任务的材料来源和设计流程,并纳入1例健康受试者,进行词图匹配语义判断任务下的fMRI、ERP实验,将任务下采集的fMRI/ERP数据进行分析,判断该任务在fMRI/ERP实验中的可行性。结果 fMRI结果显示,与注视“+”时相比,受试者在词图呈现时右侧额中回激活增高;与词图匹配条件相比,受试者在词图不匹配条件下右侧颞中回激活增高。ERP结果显示,词图匹配条件下受试者左侧额颞区激活较明显,词图不匹配条件下右侧额叶区激活较明显。结论 基于本实验设计,采用fMRI、ERP技术均可以获得语言相关脑区激活效应,提示本任务可用于探索汉语语言的脑加工机制。

大脑皮质内部的联系神经束, 对于大脑皮质之间的信息传递担任非常重要的角色. 传统的语言模型理论提出人类的2个主要语言中枢分别位于大脑皮质的左侧额下回的布罗卡区域(Broca’s area, BA44 and BA45)以及颞上回处的维尼基区域(Wernicke’s area, BA22), 而联系这2个区域的纤维束, 也就是弓状束(arcuate fasciculus). 另外, 近期研究也发现下顶叶(inferior parietal cortex, BA39 and BA40)在语音处理历程具重要性. 扩散磁振造影(Diffusion MRI)可以提供大脑白质精细的组织结构, 配合神经径路追踪(tractography)便能撷取出复杂的神经纤维连结路径. 该研究利用扩散磁振影像中的高夹角分辨率扩散磁振造影(high angular resolution diffusion imaging)与神经径路追踪技术, 呈现与语言相关的大脑机率神经连结路径(probabilistic language pathway).

通过限制球形卷积(constrained spherical deconvolution,CSD)和神经纤维追踪技术(tractography),以了解大脑左右半球的弓状束(arcuate fasciculus,AF)神经结构完整性与语言理解能力的相关性.该文使用磁共振成像(MRI)仪对14例大脑左半球罹患肿瘤的右利手患者进行了术前术后扫描(每次扫描均伴随一次波士顿失语症测试),并用分析软件DSI Studio计算术前术后左右半球弓状束的四项扩散指标,并进行了比较.结果发现左脑弓状束有两项指标在术前术后有非常显著的差异(p<0.01),而右脑四项指标均无显著改变(p>0.05).另外,该文还将扩散指标与患者相对应的语言测试所反映的语言理解能力进行了相关性分析,发现无论术前术后,左半球弓状束与语言理解能力相关系数r介于0.6~0.8之间,而右半球则仅介于0.3~0.4之间.上述结果表明,语言理解能力与左侧弓状束密切相关(p<0.01),而与右侧弓状束相关性不大,此结果与以往研究者对大脑侧化的认知相符.

Several event-related potential (ERP) studies in second language (L2) processing have revealed a differential vulnerability of syntax-related ERP effects in contrast to purely semantic ERP effects. However, it is still debated to what extent a potential critical period for L2 acquisition, as opposed to the attained proficiency level in the L2, contributes to the pattern of results reported in previous ERP studies. We studied L2 processing within the model of a miniature version of a natural language, namely Japanese, specifically constructed to assure high proficiency of the learners. In an auditory ERP experiment, we investigated sentence processing of the "Mini-Japanese" in Japanese native speakers and German volunteers before and after training. By making use of three different types of violation, namely, word category, case, and classifier violations, native and nonnative ERP patterns were compared. The three types of violation elicited three characteristic ERP patterns in Japanese native speakers. The word category violation elicited an anteriorly focused, broadly distributed early negativity followed by a P600, whereas the case violation evoked a P600 which was preceded by an N400. The classifier violation led solely to a late left distributed negativity with an anterior focus. Although the P600 was similar for Japanese natives and learners, the N400 and the anterior negativities were not present in the learner group. The differences across groups suggest deviant neural processes in on-line syntactic and thematic processing in the L2 learners despite high behavioral skills.

We present two ERP studies on the processing of word order variations in Japanese, a language that is suited to shedding further light on the implications of word order freedom for neurocognitive approaches to sentence comprehension. Experiment 1 used auditory presentation and revealed that initial accusative objects elicit increased processing costs in comparison to initial subjects (in the form of a transient negativity) only when followed by a prosodic boundary. A similar effect was observed using visual presentation in Experiment 2, however only for accusative but not for dative objects. These results support a relational account of word order processing, in which the costs of comprehending an object-initial word order are determined by the linearization properties of the initial object in relation to the linearization properties of possible upcoming arguments. In the absence of a prosodic boundary, the possibility for subject omission in Japanese renders it likely that the initial accusative is the only argument in the clause. Hence, no upcoming arguments are expected and no linearization problem can arise. A prosodic boundary or visual segmentation, by contrast, indicate an object-before-subject word order, thereby leading to a mismatch between argument "prominence" (e.g. in terms of thematic roles) and linear order. This mismatch is alleviated when the initial object is highly prominent itself (e.g. in the case of a dative, which can bear the higher-ranking thematic role in a two argument relation). We argue that the processing mechanism at work here can be distinguished from more general aspects of "dependency processing" in object-initial sentences.

In this study, event-related brain potential effects of speech processing are obtained and compared to similar effects in sentence reading. In two experiments sentences were presented that contained three different types of grammatical violations. In one experiment sentences were presented word by word at a rate of four words per second. The grammatical violations elicited a Syntactic Positive Shift (P600/SPS), 500 ms after the onset of the word that rendered the sentence ungrammatical. The P600/SPS consisted of two phases, an early phase with a relatively equal anterior-posterior distribution and a later phase with a strong posterior distribution. We interpret the first phase as an indication of structural integration complexity, and the second phase as an indication of failing parsing operations and/or an attempt at reanalysis. In the second experiment the same syntactic violations were presented in sentences spoken at a normal rate and with normal intonation. These violations elicited a P600/SPS with the same onset as was observed for the reading of these sentences. In addition two of the three violations showed a preceding frontal negativity, most clearly over the left hemisphere.

Spoken word recognition and production require fast transformations between acoustic, phonological, and conceptual neural representations. Bilinguals perform these transformations in native and non-native languages, deriving unified semantic concepts from equivalent, but acoustically different words. Here we exploit this capacity of bilinguals to investigate input invariant semantic representations in the brain. We acquired EEG data while Dutch subjects, highly proficient in English listened to four monosyllabic and acoustically distinct animal words in both languages (e.g., "paard" - "horse"). Multivariate pattern analysis (MVPA) was applied to identify EEG response patterns that discriminate between individual words within one language (within-language discrimination) and generalize meaning across two languages (across-language generalization). Furthermore, employing two EEG feature selection approaches, we assessed the contribution of temporal and oscillatory EEG features to our classification results. MVPA revealed that within-language discrimination was possible in a broad time-window (similar to 50-620 ms) after word onset probably reflecting acoustic-phonetic and semantic-conceptual differences between the words. Most interestingly, significant across-language generalization was possible around 550-600 ms, suggesting the activation of common semantic-conceptual representations from the Dutch and English nouns. Both types of classification, showed a strong contribution of oscillations below 12 Hz, indicating the importance of low frequency oscillations in the neural representation of individual words and concepts. This study demonstrates the feasibility of MVPA to decode individual spoken words from EEG responses and to assess the spectro-temporal dynamics of their language invariant semantic-conceptual representations. We discuss how this method and results could be relevant to track the neural mechanisms underlying conceptual encoding in comprehension and production.

肝癌是最常见的恶性肿瘤之一，亚洲地区最为常见的肝癌演变过程为肝炎-肝硬化结节-异型增生结节-肝细胞性肝癌．判断肝脏结节在演变过程所处分期，并采取干预措施，对降低肝癌的发生率非常关键．本文针对影像组学提出了更精确的支持向量机（SVM）分类算法——LFOA-F-SVM，用于对120名患者的腹部动态增强磁共振图像的肝脏结节进行四分类．该算法利用了考虑半径与几何间距的F-SVM，并结合莱维飞行策略（LF）的果蝇优化算法（FOA）寻求超参．为了验证方法的有效性，本文另外添加了5个UCI分类数据集（心脏、帕金森疾病、虹膜、葡萄酒和动物园），并与SVM、PSO-SVM、FOA-SVM、F-SVM进行比较．结果表明，在6个分类数据集（包括肝脏结节数据集和5个UCI分类数据集）中，相对于其他分类算法，LFOA-F-SVM的分类准确率最高，在肝脏结节数据集中的四分类精确率和查全率也较高．

直肠癌T分期对患者的术前评估有重要作用.然而，传统的放射科医生根据患者磁共振图像直接判断分期的方法效果欠佳.本文提出使用影像组学的方法预测直肠癌T分期，首先获取105例直肠癌患者影像数据，根据病理报告中的T分期结果将T1、T2期患者划分为未突破肌层组，将T3、T4期患者分为突破肌层组，整理数据得到未突破肌层组31例，突破肌层组74例.在患者的轴向位T2WI图像中勾画病灶区域，并在病灶上使用pyradiomics工具包提取影像组学特征，使用最小绝对值收敛和选择算子（LASSO）对高维特征做特征选择，得到与T分期高度相关的特征数据，使用随机森林、支持向量机（SVM）、逻辑回归、梯度提升树（GBDT）分别建模，进行交叉验证调参，评估模型性能.每层图像提取100维特征，经LASSO特征选择后得到7个与T分期高度相关的特征，使用4种模型分别建模，其中SVM算法表现最优，平均受试者操作特征曲线下面积（AUC）、准确率、灵敏度、特异度分别为0.968 5、0.886 4、0.962 5、0.899 2，测试集准确率达到了0.904 7.结果表明，使用影像组学方法可以提高直肠癌T分期预测的准确率.

Functional MRI was used to determine how the constituents of the cortical network subserving dynamic spatial working memory respond to two types of increases in task complexity. Participants mentally maintained the most recent location of either one or three objects as the three objects moved discretely in either a two- or three-dimensional array. Cortical activation in the dorsolateral prefrontal (DLPFC) and the parietal cortex increased as a function of the number of object locations to be maintained and the dimensionality of the display. An analysis of the response characteristics of the individual voxels showed that a large proportion were activated only when both the variables imposed the higher level of demand. A smaller proportion were activated specifically in response to increases in task demand associated with each of the independent variables. A second experiment revealed the same effect of dimensionality in the parietal cortex when the movement of objects was signaled auditorily rather than visually, indicating that the additional representational demands induced by 3-D space are independent of input modality. The comodulation of activation in the prefrontal and parietal areas by the amount of computational demand suggests that the collaboration between areas is a basic feature underlying much of the functionality of spatial working memory.Copyright 2000 Academic Press.

In speaking and comprehending language, word information is retrieved from memory and combined into larger units (unification). Unification operations take place in parallel at the semantic, syntactic and phonological levels of processing. This article proposes a new framework that connects psycholinguistic models to a neurobiological account of language. According to this proposal the left inferior frontal gyrus (LIFG) plays an important role in unification. Research in other domains of cognition indicates that left prefrontal cortex has the necessary neurobiological characteristics for its involvement in the unification for language. I offer here a psycholinguistic perspective on the nature of language unification and the role of LIFG.