Conflicts as aversive signals

Theories of human action control deal with the question of how cognitive control is dynamically adjusted to task demands. The conflict monitoring theory of anterior cingulate (ACC) function suggests that the ACC monitors for response conflicts in the ongoing processing stream thereby triggering the mobilization of cognitive control. Alternatively, the outcome evaluation account of ACC function suggests that the ACC monitors for negative performance outcomes, an information that serves as an aversive learning signal for future action selection. Botvinick (2007) recently suggested that both theories might converge on the detection of aversive signals in general. Here, the authors provide first evidence that conflicts are registered as aversive signals. Congruent and incongruent Stroop color-words served as primes, and positive and negative stimuli as targets in an affective priming paradigm. Negative targets were evaluated faster after incongruent than after congruent Stroop primes, and positive targets were evaluated slower after incongruent than after congruent primes. The finding that conflicts are actually registered as aversive signals bridges the gap between competing theories of ACC function and has broad theoretical and behavioral implications as it makes the conflict monitoring theory applicable to a much wider range of situations and tasks.     

内侧前额叶皮质—— “自我”的神经基础

自我神经基础的探讨常基于自我相关加工的研究, 涉及皮质中线结构各个脑区甚至全脑协同作用。内侧前额叶皮质及其次成分在自我相关加工中发挥重要作用：腹内侧前额叶皮质较多支持默认模式下的自我加工、自我信息的觉察和“在线”自我加工, 背内侧前额叶皮质主要参与有意识的自我参照加工、自我信息的评价和“主导的”自我加工。在自我-他人表征中, 自我-他人表征的情感性、认知性和文化性因素均调节内侧前额叶皮质及次成分的活动。未来在动态的时间和人际背景中解析自我加工的神经机制是重要的研究方向。     

Representations in the Human Prefrontal Cortex

ABSTRACT— The prefrontal cortex (PFC) in humans has been studied for more than a century, but many crucial questions about its functions remain unanswered. This paper will highlight a few key differences between human and animal PFCs, and between the human PFC (HPFC) and other parts of the human brain. We then make a case that the HPFC is critically important for executing behaviors over time and integrating disparate information from throughout the brain. Finally, we will focus on our position in the current debate regarding how the HPFC performs its functions and discuss future directions for research.     

Conflict and Cognitive Control in the Brain

ABSTRACT— Recent research from cognitive psychology and cognitive neuroscience has suggested that the control mechanisms by which people are able to regulate task performance can be dissociated into evaluative and executive components. One process, implemented in the anterior cingulate cortex of the brain, monitors the amount of conflict that occurs during information processing; another process, implemented in the dorsolateral prefrontal cortex, is involved with maintaining the requirements of the task at hand and with biasing information processing in favor of appropriate responses. In the current article, we review this theory and some of the research that has supported it, including its implication for understanding cognitive disturbances in clinical disorders such as schizophrenia and obsessive-compulsive disorder. We conclude by addressing several interesting possibilities for future research.     

A sensitive period for language in the visual cortex: distinct patterns of plasticity in congenitally versus late blind adults

Recent evidence suggests that blindness enables visual circuits to contribute to language processing. We examined whether this dramatic functional plasticity has a sensitive period. BOLD fMRI signal was measured in congenitally blind, late blind (blindness onset 9-years-old or later) and sighted participants while they performed a sentence comprehension task. In a control condition, participants listened to backwards speech and made match/non-match to sample judgments. In both congenitally and late blind participants BOLD signal increased in bilateral foveal-pericalcarine cortex during response preparation, irrespective of whether the stimulus was a sentence or backwards speech. However, left occipital areas (pericalcarine, extrastriate, fusiform and lateral) responded more to sentences than backwards speech only in congenitally blind people. We conclude that age of blindness onset constrains the non-visual functions of occipital cortex: while plasticity is present in both congenitally and late blind individuals, recruitment of visual circuits for language depends on blindness during childhood.     

运动区Beta节律的活动特点及功能意义

人类大脑运动皮质的Beta(15~30 Hz)和Mu节律(8~14 Hz)有共同的活动特征,研究指出二者可能是联合的脑电成分。然而越来越多研究表明运动区Beta节律可能独立于Mu节律,且具有特殊的功能意义。线索诱发的Beta节律降低、运动前Beta节律降低和运动后Beta节律回复增强都是Beta与Mu节律不同的活动形式,表明运动区Beta节律有其独特的心理意义。本文主要对运动区Beta节律不同于Mu节律的活动特征及已有的理论解释进行了梳理和分析,并结合儿童研究的数据,从发展的角度对运动后Beta节律的理论假说进行了评述,最后在此基础上为进一步探索运动区Beta节律的功能意义提出了研究的展望。     

风险决策的神经机制:基于啮齿类动物研究

风险决策是在不同选项的结果确定、并且结果出现的概率已知情况下的决策。啮齿类风险决策模型研究发现前额皮层-杏仁核-伏隔核神经环路联系是决定风险决策的选择倾向的关键。前额皮层中的眶额皮层和内侧前额皮层参与风险决策的策略形成和策略转换有关;而皮层下核团中的杏仁核、腹侧纹状体的伏隔核等结构参与策略保持、价值判断,影响决策偏向和行动强度;眶额皮层、伏隔核神经元和多巴胺神经元编码风险决策过程中的概率、风险等因素;此外,多巴胺等单胺类神经递质及受体在风险决策中有复杂的作用。     

左侧背外侧前额叶在程序性运动学习中的作用

程序性运动学习包括序列学习和随机学习。神经影像学研究表明背外侧前额叶皮层(DLPFC)和初级运动皮层(M1)在程序性运动学习中发挥重要作用,但DLPFC和M1之间的联通性及其与不同程序性运动学习的关系尚不明确。本研究采用连续反应时间任务,结合经颅磁刺激(TMS)方法,探讨左侧DLPFC到M1的联通性在不同程序性运动学习中的差异。实验1采用两连发TMS探测DLPFC到M1的最佳投射时间点;实验2,被试分为2组,分别进行序列学习和随机学习,在学习前、后采集行为学数据,以及M1的运动诱发电位和DLPFC-M1联通性的电生理学数据。行为学结果发现序列学习组的学习效果更佳;电生理学结果发现,两组被试学习前、后M1的运动诱发电位均未发生改变;在最佳时间投射点、适当刺激强度下,序列学习组DLPFC-M1联通性发生改变,且与学习成绩相关,而随机学习组没有改变。结果说明DLPFC到M1的联通性增强可能是序列学习成绩更佳的重要原因,这一结果从电生理角度为DLPFC在运动学习中的作用提供了重要证据。     

Differential involvement of left prefrontal cortex in inductive and deductive reasoning

While inductive and deductive reasoning are considered distinct logical and psychological processes, little is known about their respective neural basis. To address this issue we scanned 16 subjects with fMRI, using an event-related design, while they engaged in inductive and deductive reasoning tasks. Both types of reasoning were characterized by activation of left lateral prefrontal and bilateral dorsal frontal, parietal, and occipital cortices. Neural responses unique to each type of reasoning determined from the Reasoning Type (deduction and induction) by Task (reasoning and baseline) interaction indicated greater involvement of left inferior frontal gyrus (BA 44) in deduction than induction, while left dorsolateral (BA 8/9) prefrontal gyrus showed greater activity during induction than deduction. This pattern suggests a dissociation within prefrontal cortex for deductive and inductive reasoning.     

非人灵长类的抑制控制能力

抑制控制能力是指个体为实现特定目标对干扰性优势反应进行抑制的能力,是一种高级认知能力。该文综述了对非人灵长类抑制控制能力的研究,从抑制控制能力的行为表现,生理机制及其发生、发展几个方面进行了阐述,提供了一个从演化的角度理解人类的抑制控制能力的视角。