自然阅读的脑成像研究及其与眼动技术结合

以往的研究者主要采用单词系列呈现的实验范式对词、句子和篇章等材料进行阅读脑成像研究。针对近年来使用自然阅读范式的功能磁共振(fMRI)研究进行分析,建议在该范式下使用脑-眼动同步记录的方式,并介绍了基于注视编码的fMRI数据分析原理。新的范式和技术提高了fMRI研究的生态效度,有利于对阅读中眼动加工的脑机制进行探索,是相关研究的新趋势。未来需要在自然阅读fMRI实验中结合实验设计及其他技术以克服时间分辨率低的问题,同时要注意探讨阅读和眼动脑区的关系。     

后见之明研究综述

后见之明指后见判断(可得益于事件结果反馈的判断)与先见判断(不知晓事件结果时的判断)的系统差异,其研究范式大体可分为两类,假定型设计和记忆型设计。后见效应的研究,具有重大的理论价值和应用价值。文章对后见效应的研究范式、研究结果、及其有关理论进行了简要综述,并对其应用价值加以评述。     

锚定效应的研究范式、理论模型及应用启示

锚定效应是普遍存在的一种现象,它是指在不确定状态判断过程中,人们会以最初的信息作为参照点来调整对事件的估计,这往往会导致得出错误的判断。本文首先阐述了锚定效应的相关概念及经典研究范式,后者包括语意启动范式、数值启动范式、自发锚与外部锚启动范式等。然后对锚定效应的不充分调整启发模型、锚定调整模型、选择通达模型、双加工模型以及神经心理模型等进行了深入的探讨,并总结了锚定效应在经济管理等领域中的应用。最后指出了锚定效应的研究局限及未来的研究发展方向。     

模糊决策的认知神经机制

模糊决策是特殊、复杂的风险决策, 还是一种独立的决策类型, 是当前认知神经科学争论的热点问题。一系列的fMRI研究分别得出了不同结论, 但大多数证据支持模糊决策和风险决策之间存在分离, 模糊决策有其独特的决策机制; 模糊决策的认知神经机制也是一个亟待解决的问题。因此本研究拟应用事件相关电位技术、生物反馈技术和基因技术, 采用IGT和GDT任务范式, 通过网络成瘾人群和正常人群的对比研究, 去探索模糊决策和风险决策之间的分离; 应用事件相关电位技术和磁共振技术, 采用IGT范式和选瓶任务范式, 研究模糊决策的认知神经机制; 并从临床角度进一步验证上述结果。该项目的开展, 有助于拓广模糊决策的研究领域和视野, 对理解人类在模糊情境下的决策机制以及模糊决策和风险决策之间的关系, 具有重要的理论意义; 对临床上成瘾人群、脑损伤患者的认知诊断和治疗以及现实中企业和个人的决策, 具有重要的参考价值。     

多目标追踪的神经机制

多目标追踪任务是研究动态场景中视觉注意加工机制常用的范式。自1998年开始对多目标追踪神经机制的影像学研究以来, 研究者采用ERP和fMRI等技术对多目标注意追踪所涉及的神经电生理活动和脑功能区激活方面开展了大量研究。ERP研究发现, 追踪过程持续的ERP脑电成分如N2pc、CDA的波幅与注意追踪负荷有关, 并且出现在目标与非目标上的探测刺激诱发的脑电成分如N1、P1波幅的差异可反映注意资源的分配, 具体为目标在追踪过程中得到了激活, 而非目标受到了抑制。fMRI研究比较一致地发现了顶叶(包括前顶内沟、后顶内沟、顶上小叶)、背外侧额叶皮层等在注意追踪中的强烈激活。其中顶内沟主要与注意负荷有关, 顶内沟的活动水平直接决定了观察者注意追踪的行为表现。而顶上小叶可能更多的负责注意转移。背外侧额叶皮层可能负责追踪时的感觉运动预测过程。     

轻度认知损伤重复效应脑电研究：范式及应用

“语义一致性加重复”范式（congruity-plus-repetition paradigm）在早前重复范式的基础上增加了早期语义情境用以控制重复效应的前期成份N400和后期成份P600之间的相互干扰。作者回顾了这种范式在轻度认知损伤（mild cognitive impairment,MCI）的事件相关电位研究领域的应用,并分析了该范式在MCI的识别及预测其向痴呆转归方面的优越性。提示效应的组合更能标记正常认知老化向痴呆的动态过渡;能产生两个或多个效应组合的实验范式将是该领域未来研究方向之一。     

幽默加工中不一致探测与解决的脑机制分离

本fMRI研究使用“文字背景—漫画图片”实验范式,设计了三种实验条件（可笑、不可笑和无关）,试图对幽默加工中不一致探测与解决的脑机制进行分离。可笑与不可笑条件对比的结果与前人研究一致,证明了新实验范式的有效性。其次,无关与不可笑条件比较,右侧脑岛激活,说明脑岛可能与不一致探测有关。综合分析发现,脑岛与杏仁核可能共同参与了不一致探测加工。此外,结果还第一次区分了幽默加工中不一致解决与一般问题解决的脑区。     

阅读中的快速启动范式述评

快速启动范式（Sereno & Rayner, 1992）是一种基于呈现随眼动变化技术而设计的眼动范式,主要用于研究中央凹视野内字词识别的瞬时启动,通过精确控制启动条件和启动时窗,以考察词汇通达过程中词汇水平（如,词频、词长等）、亚词汇水平（如,语音、语义、字形等）信息的加工时序。本文从基本原理、设计基础、应用领域、注意事项等方面对快速启动范式进行了较为深入的解读和介绍,并结合已有的研究成果,指出了该范式在汉语阅读中的应用价值。     

视觉返回抑制的实验范式

综述了视觉返回抑制的实验范式及相关研究。Posner和Cohen在研究视觉空间注意内部转移过程的实验中发现了返回抑制现象,这一实验被视为经典的返回抑制实验。后来通过大量的研究,形成了线索-靶子和靶子-靶子两大实验范式。线索-靶子范式中根据线索呈现方式、任务类型、刺激呈现方式等方面的不同,又可以细分为一系列小的范式和方法;而靶子-靶子范式的应用主要集中在与辨别任务的结合,以及跨通道的研究中     

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。     

From sensory processes to conscious perception

In recent years, cognitive neuroscientists have began to explore the process of how sensory information gains access to awareness. To further probe this process, event-related functional magnetic resonance imaging (fMRI) was used while testing subjects with a paradigm known as the "attentional blink." In this paradigm, visually presented information sporadically fails to reach awareness. It was found that the magnitude and time course of activation within the anterior cingulate (BA 32), medial prefrontal cortex (BA 9), and frontopolar cortex (BA 10) predicted whether or not information was consciously perceived during the critical period for the attentional blink. These results are discussed in light of a neural framework for conscious processing.     

fMRI reliability: Influences of task and experimental design

As scientists, it is imperative that we understand not only the power of our research tools to yield results, but also their ability to obtain similar results over time. This study is an investigation into how common decisions made during the design and analysis of a functional magnetic resonance imaging (fMRI) study can influence the reliability of the statistical results. To that end, we gathered back-to-back test–retest fMRI data during an experiment involving multiple cognitive tasks (episodic recognition and two-back working memory) and multiple fMRI experimental designs (block, event-related genetic sequence, and event-related m-sequence). Using these data, we were able to investigate the relative influences of task, design, statistical contrast (task vs. rest, target vs. nontarget), and statistical thresholding (unthresholded, thresholded) on fMRI reliability, as measured by the intraclass correlation (ICC) coefficient. We also utilized data from a second study to investigate test–retest reliability after an extended, six-month interval. We found that all of the factors above were statistically significant, but that they had varying levels of influence on the observed ICC values. We also found that these factors could interact, increasing or decreasing the relative reliability of certain Task × Design combinations. The results suggest that fMRI reliability is a complex construct whose value may be increased or decreased by specific combinations of factors.     

Are errors differentiable from deceptive responses when feigning memory impairment? An fMRI study

Previous neuroimaging studies have suggested that the neural activity associated with truthful recall, with false memory, and with feigned memory impairment are different from one another. Here, we report a functional magnetic resonance imaging (fMRI) study that addressed an important but yet unanswered question: Is the neural activity associated with intentional faked responses and with errors differentiable? Using a word list learning recognition paradigm, the findings of this mixed event-related fMRI study clearly indicated that the brain activity associated with intentional faked responses was different to the activity associated with errors committed unintentionally. For intentional faked responses, significant activation was found in the ventrolateral prefrontal cortex, the posterior cingulate region, and the precuneus. However, no significant activation was observed for unintentional errors. The results suggest that deception, in terms of feigning memory impairment, is not only more cognitively demanding than making unintentional errors but also utilizes different cognitive processes.     

色-词Stroop任务中的冲突类型述评

在认知控制领域中, 色-词Stroop任务常被用于研究冲突加工的内在机制。本文首先简述色-词Stroop任务中的刺激冲突和反应冲突及研究这两类冲突常用的实验范式。然后介绍这两类冲突的神经动力学特征：事件相关电位研究显示, N450的波幅调整反映了大脑对冲突的监测, 持续电位(sustained potential, SP)的波幅调整反映了大脑对反应冲突的解决; 核磁共振成像研究显示, 前扣带回、背外侧前额叶分别在反应冲突的监测、认知控制的执行上扮演着重要的角色。文章最后针对目前研究范式存在的问题提出了改进方法和认知神经研究的新方向。     

Do women with fragile X syndrome have problems in switching attention: preliminary findings from ERP and fMRI

Fragile X syndrome (FXS) is a neurodevelopmental disorder that represents the most common known cause of developmental delay. Recent neuropsychological findings indicate that females with FXS present with a specific pattern of cognitive deficits and that these difficulties primarily involve skills requiring executive control. The present study is the first to examine the extent to which neural activity of females with FXS can be observed on a task that specifically taps two core deficits, namely switching and response inhibition. Brain activity was measured using both event-related electrical potentials (ERPs) and event-related functional MRI (fMRI) neuroimaging in separate studies using the same cognitive paradigm. Compared to controls, females with FXS were significantly slower and made more errors on trials that required an immediate response (Go) to stimulus onset but were comparable on trials that required a delayed response (Wait) to stimulus onset. At the brain level, several areas showed significantly greater activation for females with FXS compared with controls, including the cingulate cortex and left and right ventral prefrontal areas. In contrast, no areas were found to show significantly greater activation for controls compared with females with FXS.     

Anxiety and cognitive efficiency: Differential modulation of transient and sustained neural activity during a working memory task

According to the processing-efficiency hypothesis (Eysenck, Derakshan, Santos, & Calvo, 2007), anxious individuals are thought to require greater activation of brain systems supporting cognitive control (e.g.,dorsolateral prefrontal cortex; DLPFC) in order to maintain equivalent performance to nonanxious subjects. A recent theory of cognitive control (Braver, Gray, & Burgess, 2007) has proposed that reduced cognitive efficiency might occur as a result of changes in the temporal dynamics of DLPFC recruitment. In this study, we used a mixed blocked/ event-related fMRI design to track transient and sustained activity in DLPFC while high- and low-anxious participants performed a working memory task. The task was performed after the participants viewed videos designed to induce neutral or anxiety-related moods. After the neutral video, the high-anxious participants had reduced sustained but increased transient activation in working memory areas, in comparison with low-anxious participants. The high-anxious group also showed extensive reductions in sustained activation of "default-network" areas (possible deactivation). After the negative video,the low-anxiety group shifted their activation dynamics in cognitive control regions to resemble those of the high-anxious group. These results suggest that reduced cognitive control in anxiety might be due to a transient, rather than sustained, pattern of working memory recruitment. Supplementary information for this study may be found at www.psychonomic.org/archive.     

Should Psychology Ignore the Language of the Brain?

ABSTRACT— Claims that neuroscientific data do not contribute to our understanding of psychological functions have been made recently. Here I argue that these criticisms are solely based on an analysis of functional magnetic resonance imaging (fMRI) studies. However, fMRI is only one of the methods in the toolkit of cognitive neuroscience. I provide examples from research on event-related brain potentials (ERPs) that have contributed to our understanding of the cognitive architecture of human language functions. In addition, I provide evidence of (possible) contributions from fMRI measurements to our understanding of the functional architecture of language processing. Finally, I argue that a neurobiology of human language that integrates information about the necessary genetic and neural infrastructures will allow us to answer certain questions that are not answerable if all we have is evidence from behavior.     

Affective personality differences in neural processing efficiency confirmed using fMRI

To test for a relation between individual differences in personality and neural-processing efficiency, we used functional magnetic resonance imaging (fMRI) to assess brain activity within regions associated with cognitive control during a demanding working memory task. Fifty-three participants completed both the self-report behavioral inhibition sensitivity (BIS) and behavioral approach sensitivity (BAS) personality scales and a standard measure of fluid intelligence (Raven’s Advanced Progressive Matrices). They were then scanned as they performed a three-back working memory task. A mixed blocked/ event-related fMRI design enabled us to identify both sustained and transient neural activity. Higher BAS was negatively related to event-related activity in the dorsal anterior cingulate, the lateral prefrontal cortex, and parietal areas in regions of interest identified in previous work. These relationships were not explained by differences in either behavioral performance or fluid intelligence, consistent with greater neural efficiency. The results reveal the high specificity of the relationships among personality, cognition, and brain activity. The data confirm that affective dimensions of personality are independent of intelligence, yet also suggest that they might be interrelated in subtle ways, because they modulate activity in overlapping brain regions that appear to be critical for task performance.     

额叶皮层内知觉干扰与工作记忆干扰引起的抑制

抑制（inhibition）是指大脑在信息加工时,压抑或制止与当前的任务不符的干扰性的信息输入、反应输出或者内部加工的认知过程,它是额叶的最基本的功能之一,也是人类高级智能活动的最基本的认知成分之一。新近的认知神经科学的研究表明：对于不同种类的干扰信息,参与抑制过程的额叶功能区域可能并不相同。但是,对于由不同的干扰源所引起的抑制过程在额叶内的功能组织方式目前尚不清楚。本研究采用fMRI 技术以及事件相关 (event-related) 的分析方法,研究了因知觉干扰所引起的抑制过程与因工作记忆干扰所引起的抑制过程在额叶内的层级化功能组织方式。结果表明：后部的前额叶参与由知觉干扰所引起的抑制过程,而前部的前额叶则参与由工作记忆干扰所引起的抑制过程