风险决策过程验证：补偿/非补偿模型之争的新认识与新证据

风险决策是人类赖以生存和发展的重大决策。如何进行风险决策是人类不断认识和改造世界过程中遇到的未解之谜。主流风险理论认为, 风险决策是一个补偿性的、期望值最大化的过程; 而非主流的风险理论则认为, 风险决策是非补偿性的, 并不遵循期望法则所假设的加权求和等过程。这一谜团为何一直没有得以破解, 或许是因为我们未找到揭示其心理过程的令人信服的证据。近10年来, 我们针对风险决策过程, 借助行为实验、眼动记录法、事件相关电位、功能磁共振成像等技术, 系统探索风险决策的心理和神经机制, 为回答“风险决策是否遵循补偿性规则”这一问题提供了汇聚性证据。本文依据期望法则所假设的概率函数推导、加权过程、加权求和过程、总分最大化等步骤, 对这些研究进行梳理与回顾, 以期加深人们对风险决策机制的理解, 并为建立、健全与风险决策相关的政策、法律法规提供理论依据。     

大脑腹侧视觉通路知觉表征神经机制研究

大脑腹侧视觉通路知觉表征的神经机制是认知神经科学研究面临的基本问题。本文系统介绍了该问题研究中比较有影响力的理论模型,归纳分析了模型之间的分歧与各自的局限。文章分析指出大脑自上而下的调控机制是腹侧视觉通路神经表征机制问题研究的另一重要维度,如何有效整合知觉表征模型与大脑调控机制的相关研究是进一步深化知觉表征神经机制问题研究的关键。     

基于神经生理学的疼痛测量

疼痛是一种受多重因素影响的复杂主观感受。临床上,疼痛测量主要依赖于患者的主观评价。然而,这种传统的疼痛测量方法具有多方面的局限。近年来,研究者借助生理记录、脑电和功能磁共振等技术,揭示疼痛的神经生理、心理机制,挖掘与疼痛相关的神经生理指标,进而构建有效、客观和精确的疼痛评价体系。在基础研究和临床实践中,这些技术有望弥补传统疼痛测量方法的不足,从而极大推动疼痛测量及其治疗等相关领域研究的发展。     

An fMRI study of phonological and spatial working memory using identical stimuli

The aim of the present fMRI study was to localize brain areas that were uniquely activated for phonological versus spatial working memory. Previous studies have reported inconsistent results, most likely because of methodological heterogeneity varying both stimuli and instructions in the same study. Here, identical consonant-vowel-consonant non-words were visually presented to the subjects in a 2-back paradigm under two different instructions; the subjects either had to memorize the non-words per se or their location. The results give evidence for a hemispheric organization of working memory, with dominance for processing of phonological information in the left hemisphere and frontal cortex, and spatial information in the right hemisphere and parietal cortex. The results also reflect a certain overlap between the neuronal network for working memory and processing of verbal and spatial material. These findings are discussed with regard to processing specificity and the extent that activated areas also may reflect perceptual processes.     

Syntax as a reflex: neurophysiological evidence for early automaticity of grammatical processing

It has been a matter of debate whether the specifically human capacity to process syntactic information draws on attentional resources or is automatic. To address this issue, we recorded neurophysiological indicators of syntactic processing to spoken sentences while subjects were distracted to different degrees from language processing. Subjects were either passively distracted, by watching a silent video film, or their attention was actively streamed away from the language input by performing a demanding acoustic signal detection task. An early index of syntactic violations, the syntactic Mismatch Negativity (sMMN), distinguished between grammatical and ungrammatical speech even under strongest distraction. The magnitude of the early sMMN (at <150ms) was unaffected by attention load of the distraction task. The independence of the early syntactic brain response of attentional distraction provides neurophysiological evidence for the automaticity of syntax and for its autonomy from other attention-demanding processes, including acoustic stimulus discrimination. The first attentional modulation of syntactic brain responses became manifest at a later stage, at approximately 200ms, thus demonstrating the narrowness of the early time window of syntactic autonomy. We discuss these results in the light of modular and interactive theories of cognitive processing and draw inferences on the automaticity of both the cognitive MMN response and certain grammar processes in general.     

Seeing is believing: the effect of brain images on judgments of scientific reasoning

Brain images are believed to have a particularly persuasive influence on the public perception of research on cognition. Three experiments are reported showing that presenting brain images with articles summarizing cognitive neuroscience research resulted in higher ratings of scientific reasoning for arguments made in those articles, as compared to articles accompanied by bar graphs, a topographical map of brain activation, or no image. These data lend support to the notion that part of the fascination, and the credibility, of brain imaging research lies in the persuasive power of the actual brain images themselves. We argue that brain images are influential because they provide a physical basis for abstract cognitive processes, appealing to people's affinity for reductionistic explanations of cognitive phenomena.     

False recognition of emotional stimuli is lateralised in the brain: An fMRI study

We have investigated whether the left (LH) and right (RH) hemisphere play a different role in eliciting false recognition (FR) and whether their involvement in this memory illusion depends on the emotional content of stimuli. Negative and neutral pictures (taken from IAPS) were presented in the divided-visual field paradigm. Subjects task was to indicate whether the pictures had already been presented or not during the preceding study phase. FR rate was much higher for the RH than the LH presentations. In line, FR resulted in activations mainly in the right prefrontal cortex (PFC) for either RH or LH presentations. Emotional content of stimuli facilitated the formation of false memories and strengthened the involvement of the right PFC in FR induction.     

面孔倒置效应的研究与理论述评

面孔倒置效应是指, 个体对倒置面孔的再认成绩显著低于对正立面孔的再认成绩, 而且, 与普通物体的倒置效应相比, 面孔的倒置效应更大。研究者们针对面孔倒置效应提出了多种理论假说, 两种主要的理论解释是：第一, 倒置面孔破坏了面孔的结构特征, 影响了面孔的整体加工, 所以, 个体对倒置面孔的再认成绩较差; 第二, 眼睛在面孔加工中起重要作用, 尤其在倒置面孔中的作用更明显, 使得倒置面孔N170波幅较高。ERP和fMRI研究提示, 未来研究需要进一步明确眼睛、注意等在面孔倒置效应中的作用。     

学习技能形成中的脑加工

对运动学习,视知觉学习,镜像阅读,语法学习和动词产生学习的脑实验研究,主要有单通路调节加工模型和双通路转换加工模型,实验侧重研究学习的时间进程。     

The effects of music exposure and own genre preference on conscious and unconscious cognitive processes: a pilot ERP study

Did Beethoven and Mozart have more in common with each other than Clapton and Hendrix? The current research demonstrated the widely reported Mozart Effect as only partly significant. Event-related brain potentials (ERPs) were recorded from 16 professional classical and rock musicians during a standard 2 stimulus visual oddball task, while listening to classical and rock music. During the oddball task participants were required to discriminate between an infrequent target stimulus randomly embedded in a train of repetitive background or standard stimuli. Consistent with previous research, the P3 and N2 ERPs were elicited in response to the infrequent target stimuli. Own genre preference resulted in a reduction in amplitude of the P3 for classical musicians exposed to classical music and rock musicians exposed to rock music. Notably, at the pre-attentive stage of processing (N2) beneficial effects of exposure to classical music were observed for both groups of musicians. These data are discussed in terms of short and long-term music benefits on both conscious and unconscious cognitive processes.