Cognitive deficits in relation to personality type and hypothalamic-pituitary-adrenal (HPA) axis dysfunction in women with stress-related exhaustion

Exhaustion caused by long-term work-related stress may cause cognitive dysfunction. We explored factors that may link chronic stress and cognitive impairment. Personality, psychiatric screening, and behavior were assessed by self-reporting measures in 20 female patients (mean age 39.3 years; range 26-53) with a preliminary diagnosis of stress-related exhaustion and in 16 healthy matched controls. Cognitive performance was investigated with a detailed neuropsychological test battery. Cortisol axis function was assessed by urinary and saliva collections of cortisol, dexamethasone suppression, Synacthen response, and corticotropin-releasing hormone (CRH) tests. Proinflammatory cytokines were measured. Hippocampal volumes were estimated by magnetic resonance imaging. Multivariate and univariate statistical methods were used to explore putative differences between groups and factors linked to cognitive impairment. Cognitive function clearly differed between groups, with decreased attention and visuospatial memory in the patient group, suggesting frontal cortex/medial temporal cortex-network dysfunction. Increased harm avoidance and persistence was present among patients, with lowered self-directedness linked to lower quality of life, increased anxious and depressive tendencies, and experiences of psychosocial stress. Attention was decreased with concomitantly impaired visuospatial memory. The pituitary (adrenocorticotropic hormone, ACTH) response to CRH was decreased in patients, with an increased cortisol/ACTH response to CRH. However, cortisol production rates, diurnal or dexamethasone-suppressed saliva cortisol levels, and the cortisol response to Synacthen were unaltered. Hippocampal volumes did not differ between groups. These findings suggest that cognitive dysfunction in stress-related exhaustion is linked to distinct personality traits, low quality of life, and a decreased ACTH response to CRH.     

内侧颞叶与来源记忆

来源记忆不同于项目记忆。早期的研究认为来源记忆的神经基础主要是前额叶,但近几年的相关研究发现内侧颞叶在来源记忆中的作用也是相当重要的,健康被试的功能神经成像研究和内侧颞叶损伤病人研究都为内侧颞叶在来源记忆中的作用提供了可靠证据。     

Brain mechanisms associated with background monitoring of the environment for potentially significant sensory events

Background monitoring is a necessary prerequisite to detect unexpected changes in the environment, while being involved in a primary task. Here, we used fMRI to investigate the neural mechanisms that underlie adaptive goal-directed behavior in a cued task switching paradigm during real response conflict or, more generally, when expectations on the repetitive features of the environment were violated. Unexpected changes in sensory stimulus attributes in the currently unattended stimulus dimension thereby led to activations in a bilateral network comprising inferior lateral frontal, intraparietal, and posterior medial frontal brain regions, independent of whether these attributes elicited a factual response conflict or not. This fronto-parietal network may thus play an important role in adaptive responding to potentially significant events outside the current focus of attention.     

Certain Emotional Factors in Learning and Efficiency

A group of measures duplicating the original battery of tests which Halstead used to obtain his four biological intelligence factors were given to a group of subjects with acute lateralized brain lesions. These results were compared to the results of the same battery when administered to subjects with chronic diffuse brain damage. This comparison demonstrated that the factors derived from brain damage testing are affected by (a) the subjects' mental abilities, (b) the sensitivity of the measures to brain damage in general, and (c) the lateralization of the damage.     

Executive Function: The Search for an Integrated Account

ABSTRACT— In general, executive function can be thought of as the set of abilities required to effortfully guide behavior toward a goal, especially in nonroutine situations. Psychologists are interested in expanding the understanding of executive function because it is thought to be a key process in intelligent behavior, it is compromised in a variety of psychiatric and neurological disorders, it varies across the life span, and it affects performance in complicated environments, such as the cockpits of advanced aircraft. This article provides a brief introduction to the concept of executive function and discusses how it is assessed and the conditions under which it is compromised. A short overview of the diverse theoretical viewpoints regarding its psychological and biological underpinnings is also provided. The article concludes with a consideration of how a multilevel approach may provide a more integrated account of executive function than has been previously available.     

Magnitude and chronometry of neural mechanisms of emotion regulation in subtypes of aggressive children

Emotion regulation is a key social skill and children who fail to master it are at risk for clinical disorders. Specific styles of emotion regulation have been associated with particular patterns of prefrontal activation. We investigated whether anxious aggressive children would reveal a different pattern of cortical activation than non-anxious aggressive children and normally-developing children. We examined the magnitude and timing of source activation underlying the N2—an ERP associated with inhibitory control—during a go/nogo task with a negative emotion induction component (loss of earned points). We estimated cortical activation for two regions of interest—a ventral prefrontal and a dorsomedial prefrontal region—for three 100-ms windows over the range of the N2 (200–500 ms). Anxious aggressive children showed high ventral prefrontal activation in the early window; non-anxious aggressive children showed high ventral prefrontal activation in the late window, but only for the duration of the emotion induction; and normally-developing children showed low ventral prefrontal activation throughout. There were no group differences in dorsomedial prefrontal activation. These results suggest that anxious aggressive children recruit ventral prefrontal activation quickly and indiscriminately, possibly giving rise to their rigid, threat-oriented approach to conflict. The late ventral prefrontal activation seen for non-anxious aggressive children may underlie a more delayed, situation-specific, but ineffective response to frustration.     

Executive function as a function of sub-clinical psychopathy

Some aspects of executive function are thought to be dysfunctional in psychopathic individuals. We administered a small battery of neuropsychological tests (spatial alternation task, object alternation task, and Porteus Maze) to two samples of college students and obtained a measure of psychopathy via a self-report questionnaire. Psychopathic traits were related to the tests of object alternation and Porteus Maze but not to the spatial alternation task. Our results support the hypothesis of orbitofrontal cortex (OFC) dysfunction with sparing of dorsolateral prefrontal cortex (DLPFC) in psychopathy and provide a downward extension of this theory to sub-clinical levels of psychopathy.     

价值观的神经机制:另一种研究视角

神经机制分析是价值观研究的一种新视角.内稳态机制和情绪反应的固有模式可能体现出价值观的神经生物原型.社会认知神经科学试图从子价值观、价值取向、价值观结构等方面寻找价值观的神经实体证据,也对价值评价、价值决策等相关过程进行了神经活动分析.初步发现了个体价值观与部分脑区活动的相关关系,涉及前额叶-顶叶-颞叶神经网络带的众多大脑结构.未来研究可沿循静态的价值观结构和动态的价值观加工过程两条线路,整合和完善现有分散的神经生理研究,将有助于更系统地理解价值观的神经机制.     

早期高级认知发展与前额叶功能发育的fNIRS研究

儿童早期阶段是各项认知能力和脑发育的关键阶段。近红外光谱成像技术(fNIRS)凭借其非侵害性、便捷操作以及对头动容忍度高等特点,在早期阶段儿童认知发展与脑发育的研究中得到越来越多的应用。从早期高级认知发展与前额叶功能的单侧优势变化、对应前额叶脑区逐渐专门化、发展关键期与前额叶功能的可塑性,以及前额叶功能异常与早期发展障碍的关系等四个方面对基于fNIRS技术开展的早期认知发展与脑发育的研究进展进行了梳理和分析。指出未来研究应探究儿童早期认知能力发展和脑发育的轨迹及关键期,探讨有发展性障碍家族风险儿童的早期大脑发育特点,为早期教育和发展障碍的早期预警提供依据。