双侧前额皮层的语言功能--用近红外技术研究语言功能的初步实验

本文报告一个用近红外技术进行的语言认知脑成像实验.实验通过脑f血流的变化情况考察了双侧前额皮层对由不同通道输入的,不同语言的各个层次的认知反应.实验结果表明,双侧前额皮层对高层语义加工,包括对篇章的归纳与抽象,具有特殊的功能,这种功能的神经学分布是对称的,这种功能及其对称性不随语言和输入通道的变化而变化.相比之下,前额皮层对读、听语言材料以及听音乐却显得不敏感.局部血流的变化只显示其对上述任务的一般性的注意力控制.     

Relationships between executive function,working memory,and decision-making on the Iowa Gambling Task: Evidence from ventromedial patients,dorsolateral patients,and normal subjects

The results of previous studies are inconsistent in regard to the relationship between the Iowa Gambling Task (IGT), working-memory (WM), and executive tasks, and whether these cognitive processes could be considered as mechanisms underlying a decision-making deficit. Moreover, the relationship between the IGT and executive measures is examined based on a limited number of executive tasks, within different populations showing diffuse damage. In addition, there are fewer studies carried out within control participants, with those studies also being inconclusive. It is also suggested that the association of the IGT performance with executive tasks depends on whether the IGT was running under ambiguity or under risk. In this work, all of these issues are studied. Results showed that both patients with ventromedial (VMPFC, N = 10) and dorsolateral (DLPFC, N = 10) prefrontal cortex lesions are significantly impaired on almost all executive tasks, WM tasks, and the IGT. Furthermore, when the IGT is run under risk, there are significant correlations between executive measures and the IGT for the DLPFC patients and the control participants (N = 34) but not the VMPFC patients. No correlation was found between WM tasks and the IGT for both frontal subgroups and control participants. These findings suggested that the mechanisms underlying the IGT deficit differ according to the lesion locations.     

Can Constructive Thinking Predict Decision Making?

We assume that executive function constitutes an integrated set of cognitive processes that mediate working memory, planning, inhibition, flexibility, and decision making. Despite the acknowledged theoretical connection between executive function processes and emotional intelligence, such relationships have rarely been investigated. The purpose of this study was to examine the potential relationship between constructive thinking, conceived as a component of emotional intelligence, and executive function, as indexed by various existing neuropsychological and experimental instruments. We used the Constructive Thinking Inventory as a measure of emotional intelligence. We found that some constructive thinking subscales were able to predict distinct executive function variables. Emotional Coping, Categorical Thinking, and Esoteric Thinking subscales explained performance on various measures of executive function. Thus, we conclude that intervention programs designed to train a specific component of emotional intelligence, namely constructive thinking, could also facilitate performance in executive function processes, and vice versa. Copyright © 2011 John Wiley & Sons, Ltd.     

自我控制资源与认知资源相互影响的机制:整合模型

尽管有学者认为自我控制资源和认知资源应该是两种独立的资源,但近期的研究却表明两种资源是互相影响的.以往研究从执行控制的角度解释两种资源为什么相互影响,但却没有指出两种资源如何影响执行控制,以及缺乏考虑神经机制和自我控制资源调节变量在其中的作用.为更系统地解释两种资源相互影响的机制,作者提出了一个整合模型,该模型指出:(1)两种资源相互影响的主要原因是两者都受到执行控制和前额叶皮层的影响;(2)个体进行自我控制或认知加工会消耗能量,产生心理疲劳,降低执行任务的动机,表现为前额叶皮层激活水平下降;(3)前额叶皮层激活不足进一步限制了执行控制在随后的自我控制和认知加工任务中的作用,因而影响后续自我控制或认知加工任务的表现;(4)自我控制资源调节变量通过提高个体对疲劳的耐受性、补充能量和提高动机等方法,使前额叶皮层和执行控制在完成前一阶段任务后仍然能够正常发挥作用,从而维持个体在后续自我控制或认知加工任务上的表现.未来的研究可考察自我控制资源与其他认知加工的关系;用动态的认知神经研究方法,建立前额叶皮层激活水平在前后两阶段任务之间的中介作用模型,以及研究自我控制资源调节变量的神经机制.     

Neuromagnetic correlates of intra- and extra-dimensional set-shifting

Set-shifting is essential to cognitive flexibility and relies on frontal lobe function. Previous studies have mostly focused on feedback processes following shifting rather than set-shifting itself. We designed an MEG paradigm without feedback to directly investigate the neural correlates of set-shifting. Adults (n = 16) matched one of two coloured images with a third stimulus, the target, by either the colour or shape dimension of the target. Half of the shift trials involved colour-to-colour or shape-to-shape (intra-dimensional: ID) shifting and the other half involved colour-to-shape or shape-to-colour (extra-dimensional: ED) shifting. MEG was continuously recorded on a 151 channel CTF system. We used beamforming to analyze responses to the first (shift) and the third (repeat) trials in each set. These trials were contrasted separately for ID and ED sets. Shift versus repeat trials showed larger MEG activations for intra-dimensional shifting in the right inferior frontal gyrus (BA 47), left medial frontal gyrus (BA 10) and right superior frontal gyrus (BA 9) as early as 100 ms, and in left middle frontal gyrus (BA 11) between 250–500 ms. Activations related to extra-dimensional shifting were detected in left inferior frontal gyrus (BA 44), left middle frontal gyrus (BA 11), and right middle frontal gyrus (BA 46) between 100 ms and 350 ms, followed by superior frontal gyrus (BA 8/BA 10) between 250–500 ms. Intra-dimensional and extra-dimensional shifting also activated bilateral and right parietal areas, respectively. This study establishes the location and timing of frontal and parietal activations during an intra-dimensional versus extra-dimensional shifting task.     

Role of medial prefrontal cortex in representing one’s own subjective emotional responses: A preliminary study

The medial prefrontal cortex (mPFC) has been implicated in attending to one’s own emotional states, but the role of emotional valence in this context is not understood. We examined valence-specific BOLD activity in a previously validated functional magnetic resonance imaging (fMRI) paradigm. Ten healthy subjects viewed emotional pictures and categorized their experience as pleasant, unpleasant or neutral. All three categories activated a common region within mPFC. Subtraction of neutral from pleasant or unpleasant conditions instead revealed ventromedial PFC (vmPFC), suggesting that this region represents emotional valence. During exteroceptive attention, greater mPFC responses were observed in response to emotional relative to neutral stimuli, consistent with studies implicating mPFC in the top-down modulation of emotion-biased attention. These findings may help to integrate the two proposed roles of mPFC in emotional representation and top-down modulation of subcortical structures.     

A Review of Preclinical Studies to Understand Fear During Adolescence

The most rapid physical and psychological growth occurs during adolescence, a period of transition from childhood to adulthood when the incidence of anxiety disorder peaks in humans. Human and animal studies suggest that dramatic changes in prefrontal cortical areas during adolescence are responsible for such prevalence of anxiety. Only recently, however, has the relationship between prefrontal immaturity and differential fear processing across adolescence been directly and systematically examined. Such progress is largely due to the culmination of rodent studies that delineated the fear learning, expression, and inhibition neural circuitry, and preclinical studies that provided avenues for translation. This article summarises those initial findings on the circuitry of fear inhibition, and describes in detail the new findings on adolescent fear inhibition that highlight the prefrontal cortex as a key, unrefined brain region that may govern adolescent vulnerability to anxiety disorders. Specifically, adolescent rodents have been demonstrated to be impaired in inhibiting learned fear responses following fear extinction due to prefrontal immaturity, a discovery that was shortly after replicated in adolescent humans (at least the behavioural component). Our desire for this article is to acquaint both research and clinical psychologists with the neural circuitry of fear learning and extinction, turn the attention to developmental work, and facilitate translation of preclinical rodent findings in humans.     

Online monitoring of the social presence effects in a two‐person‐like driving video game using near‐infrared spectroscopy

We examined how a friend's presence affects a performer's prefrontal activation in daily‐life activities using two wireless portable near‐infrared spectroscopy (NIRS) devices. Participants played a driving video game either solely in the single group or with a friend in the paired group. The two groups (single and paired) were subdivided according to their game proficiency (low and high). The NIRS data demonstrated a significant interaction of group by proficiency. Low‐proficiency players in the paired group showed lower activation than those in the single group, but high‐proficiency players did not. In the paired group, high‐proficiency players showed higher activation than low‐proficiency players, but not in the single group. These results suggest that NIRS detects social presence effects in everyday situations: decreasing prefrontal activation in low‐proficiency performers due to tension reduction and increasing prefrontal activation in high‐proficiency performers due to increased arousal.