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.     

现实性监控研究述评

现实性监控是来源记忆的重要组成部分.总结分析表明,现实性监控的研究成果主要体现在如下方面：①学习项目的比例、学习和测验阶段之间的干扰任务、被试的想象能力等均对现实性监控存在一定的影响;②儿童的现实性监控能力随年龄增长而提高,老人的现实性监控能力相对较低;③不同病人在现实性监控中有不同的困难;④内部来源与外部来源提取激活的大脑区域不同,前额区在区分两类项目时的作用明显.今后应在整合研究结论、建立相应认知模型、构建前额区和顶区联合作用的神经网络和应用推广等方面加强研究.     

Testing the involvement of the prefrontal cortex in lucid dreaming: A tDCS study

Recent studies suggest that lucid dreaming (awareness of dreaming while dreaming) might be associated with increased brain activity over frontal regions during rapid eye movement (REM) sleep. By applying transcranial direct current stimulation (tDCS), we aimed to manipulate the activation of the dorsolateral prefrontal cortex (DLPFC) during REM sleep to increase dream lucidity. Nineteen participants spent three consecutive nights in a sleep laboratory. On the second and third nights they randomly received either 1 mA tDCS for 10 min or sham stimulation during each REM period starting with the second one. According to the participants’ self-ratings, tDCS over the DLPFC during REM sleep increased lucidity in dreams. The effects, however, were not strong and found only in frequent lucid dreamers. While this indicates some preliminary support for the involvement of the DLPFC in lucid dreaming, further research, controlling for indirect effects of stimulation and including other brain regions, is needed.     

Alcohol increases hypnotic susceptibility

One approach to hypnosis suggests that for hypnotic experience to occur frontal lobe activity must be attenuated. For example, cold control theory posits that a lack of awareness of intentions is responsible for the experience of involuntariness and/or the subjective reality of hypnotic suggestions. The mid-dorso-lateral prefrontal cortex and the ACC are candidate regions for such awareness. Alcohol impairs frontal lobe executive function. This study examined whether alcohol affects hypnotisability. We administered 0.8 mg/kg of alcohol or a placebo to 32 medium susceptible participants. They were subsequently hypnotised and given hypnotic suggestions. All participants believed they had received some alcohol. Participants in the alcohol condition were more susceptible to hypnotic suggestions than participants in the placebo condition. Impaired frontal lobe activity facilitates hypnotic responding, which supports theories postulating that attenuation of executive function facilitates hypnotic response, and contradicts theories postulating that hypnotic response involves enhanced inhibitory, attentional or other executive function.     

Rostro‐caudal and dorso‐ventral gradients in medial and lateral prefrontal cortex during cognitive control of affective and cognitive interference

Characterizing the anatomical substrates of major brain functions such as cognition and emotion is of utmost importance to the ongoing efforts of understanding the nature of psychiatric ailments and their potential treatment. The aim of our study was to investigate how the brain handles affective and cognitive interferences on cognitive processes. Functional magnetic resonance imaging investigation was performed on healthy individuals, comparing the brain oxygenation level dependent activation patterns during affective and cognitive counting Stroop tasks. The affective Stroop task activated rostral parts of medial prefrontal cortex (PFC) and rostral and ventral parts of lateral PFC, while cognitive Stroop activated caudal parts of medial PFC and caudal and dorsal parts of lateral PFC. Our findings suggest that the brain may handle affective and cognitive interference on cognitive processes differentially, with affective interference preferentially activating rostral and ventral PFC networks and cognitive interference activating caudal and dorsal PFC networks.     

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.     

社会决策中的公平准则及其神经机制

社会决策中的公平准则一直受到广泛的关注,经济学家和心理学家们分别从动机和认知的角度对这个课题进行了深入探索.在这些工作中,最为突出的是“均等”,“互惠”和“情绪”三个模型的提出.均等和互惠模型试图从动机角度理解个体的公平行为,而情绪模型则更强调个体在公平决策中的认知和情绪的加工过程.近年来脑成像的研究也为这些模型提供了相应的支持,其中与公平准则最密切的脑区是脑岛和背外侧前额叶:前者一般被认为是反映了个体面对不公平待遇时的负性情绪体验;而后者主要负责决策过程中的抑制控制.但这些脑区具体的功能还存在很多争议,反映了不同理论模型对特定脑区功能的不同理解.未来研究应注意三个模型之间的相互补充,以及加强多模态的脑指标的运用,并注重相关脑区的整体性,此外,公平决策行为中的个体差异,以及社会情境对其的影响也应受到重视.     

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.