发展性阅读障碍的视听时间敏感性缺陷及其脑神经机制

阅读是一个视听加工过程,阅读障碍的产生可能是过程中视听时间敏感性缺陷的结果。视听时间敏感性指个体对视觉和听觉刺激出现时间的感知能力,可通过同时性判断、时间顺序判断和视听整合考察。研究发现,阅读障碍者在这一能力上表现出行为和脑层面异常。而这些研究多是拼音文字背景,汉语文字下该领域研究相当少。未来需要丰富实验设计,扩大对汉语背景下视听时间敏感性研究,并以此开发干预手段,为阅读障碍的机制和治疗提供借鉴。     

Disfluency clusters in speakers with and without neurogenic stuttering following traumatic brain injury

PurposeAnalyze the characteristics and rate of disfluency clusters in adults with and without neurogenic stuttering after traumatic brain injury (TBI).MethodTwenty adults with TBI participated in this study, including 10 with neurogenic stuttering (Group B) and 10 without -stuttering (Group A). Disfluency clusters in speech samples were classified into three types: Stuttering-like (SLD), other (OD), and mixed (MIX).ResultsSpeakers with and without neurogenic stuttering produced the same mean number of disfluency clusters. In addition, the mean length of clusters did not differ between these speaker groups although the longest clusters did. The most frequently occurring cluster type for people with neurogenic stuttering was MIX and OD for people without stuttering. Although the speakers in Group A produced stuttering-like disfluencies, these never occurred together to form a SLD type cluster. For Group B, the starter units of the clusters were usually stuttering-like disfluencies, while for Group A, the starter units were mostly interruptions.ConclusionsCompared to non-stuttering speakers, stuttering after TBI did not increase the number of clusters, but rather lengthened them. In speakers with neurogenic stuttering, the number and length of clusters were related to the manifestation of other communication deficits, not to the frequency of stuttering-like disfluencies. Still, SLD clusters occurred only in those people with neurogenic stuttering. These findings raise questions about the nature of both neurogenic stuttering and the dynamics of disfluency clustering.     

A neurodevelopmental perspective on male violence

Research is increasingly documenting a neurobiological basis to violence. This review takes a neurodevelopmental perspective on the very small group of males who grow up to become persistent violent offenders. After outlining six criteria for what constitutes a neurodevelopmental disorder, the extent to which chronic violence meets these definitional criteria is examined, covering the fields of genetics, structural and functional brain imaging, and neuropsychology. Early health risk factors for violence are then outlined, including birth complications, minor physical anomalies, prenatal smoking and alcohol exposure, poor nutrition, lead exposure, and traumatic brain injury. Persistent adult violence is argued to originate in aberrant temperamental behavior in early childhood, to have a stable developmental trajectory, and to be associated with impaired education, social, and occupational functioning. Taken together, it is argued that chronic adult violence meets criterion for being conceptualized as having neurodevelopmental origins and that an important, but not sole, source of neural maldevelopment lies in prenatal and early postnatal risk factors. This review concludes with a recognition of the sociopolitical context within which a neurodevelopmental perspective on chronic violence sits, together with directions for future research, including whether a neurodevelopmental hypothesis is best applied to reactive as opposed to proactive aggression.     

Does transcranial direct current stimulation during writing alleviate upper limb freezing in people with Parkinson’s disease? A pilot study

Transcranial direct current stimulation (tDCS) over the primary motor cortex (M1) can boost motor performance in Parkinson’s disease (PD) when it is applied at rest. However, the potential supplementary therapeutic effect of the concurrent application of tDCS during the training of motor tasks is largely unknown. The present study examined the effects of tDCS on upper limb motor blocks during a freezing-provoking writing task (the funnel task) requiring up- and down-stroke movements at alternating amplitudes. Ten PD patients and 10 age-matched controls underwent two sessions of writing combined with 20 min of anodal or sham tDCS on the left M1 in a randomized cross-over design. The primary outcome was the number of upper limb freezing episodes during five trials of the funnel task on a touch-sensitive tablet. PD patients showed a significant reduction in freezing episodes during tDCS compared to sham. No effects of tDCS were found for the amplitude, variability and speed of the strokes outside the freezing episodes. However, patients who reported freezing episodes in daily life (N = 6) showed a beneficial effect of tDCS on stroke characteristics. These results indicate a subgroup-dependent variability in response to non-invasive brain stimulation applied during the performance of motor tasks in PD. This warrants future studies to examine tDCS as an adjuvant tool for training programs aimed to reduce motor deficits related to freezing.     

句法加工的脑机制

语言理解中,句法加工至关重要,它把各个意义单元以不同的方式整合起来,从而形成整体的意义表征。句法加工的脑机制是心理语言学比较关注的问题,目前由于ERP技术和功能成像技术的进步,使对这一机制的探讨成为可能。该文对有关句法加工的脑机制的研究进行了回顾与总结,并针对目前该领域存在的问题与争论进行了讨论     

情绪应激对不同脑区c-fos表达的影响

利用电击信号和空瓶刺激两种情绪应激体液免疫调节作用动物模型,以c-fos原癌基因为探针,观察情绪应激后2个小时,大鼠全脑的c—fos原癌基因表达情况,探讨情绪应激对不同脑区c—fos表达的影响。结果表明,电击信号和空瓶刺激两种情绪应激源均能引起某些脑区或核团的c—fos蛋白表达明显增加,包括额皮质、扣带皮质、杏仁内侧核、前连合核、下丘脑背内侧核弥散部、弓状核、孤束核。结果提示,这些脑区或核团是情绪应激主要激活的中枢部位。     

琥珀酰明胶容量治疗对脑死亡后血清TNF—α、IL－1β、IL－6水平的影响

为了观察脑死亡后不同液体容量治疗对血清肿瘤坏死因子－α（TNF—α）、白细胞介素－1β（IL-1β）和白细胞介素－6（IL－6）等炎症介质水平改变的影响,选用巴马小型猪15只,随机分为3组各5只,即对照组（C组）、4％改良琥珀酰明胶组（MFG组）及乳酸林格氏液组（RL组）。C组不建立脑死亡模型,给与乳酸林格氏液30ml·kg^-1·d^-1～40ml·kg^-1·d^-1。MGF组和RL组为脑死亡组,采用颅内加压法建立脑死亡模型,MFG组给与4％改良琥珀酰明胶溶液30ml·kg^-1·d^-1,RL组给与乳酸林格氏液30-40ml·kg^-1·d^-1。分别于麻醉后及首次判定脑死亡后3、16、12、18和24h留取血样,检测血清中TNF-α、IL-1β、IL--6水平。结果发现MGF组较RL组血压和心率平稳;RL组TNF--α、IL-1β和IL-6水平自脑死亡后3h点开始逐渐升高;MFG组TNF--α、IL--1β和IL-6水平脑死亡后3h点开始亦升高,但升高幅度均较RL组低;三组间自脑死亡后3h点开始,组间比较差异有统计学意义。提示脑死亡后血清炎症介质TNF—α、IL-1β和IL--6释放增加,琥珀酰明胶可抑制脑死亡后TNF--α、IL--6、IL-1β等炎症介质的释放,减轻炎症反应,改善机体状况。     

Neurocognitive Aging and the Compensation Hypothesis

ABSTRACT— The most unexpected and intriguing result from functional brain imaging studies of cognitive aging is evidence for age-related overactivation: greater activation in older adults than in younger adults, even when performance is age-equivalent. Here we examine the hypothesis that age-related overactivation is compensatory and discuss the compensation-related utilization of neural circuits hypothesis (CRUNCH). We review evidence that favors a compensatory account, discuss questions about strategy differences, and consider the functions that may be served by overactive brain areas. Future research directed at neurocognitively informed training interventions may augment the potential for plasticity that persists into the later years of the human lifespan.     

Media Violence and Social Neuroscience: New Questions and New Opportunities

ABSTRACT— Decades of research have demonstrated that exposure to violence on television can cause increases in aggression. The recent emergence of violent video games has raised new questions regarding the effects of violent media. The General Aggression Model (GAM) predicts that exposure to violent media increases aggressive behavior through one of three primary pathways (arousal, cognitions, and affect). Past psychophysiological research has supported GAM but has been limited to examining arousal-related variables. Recent advances in social neuroscience have opened the door to investigations of exposure to violent media on cognitive and affective components and their neurocognitive underpinnings. Neuroscience tools have the potential to provide answers to the new questions posed by recent advances in media technology.     

The organisation and content of trauma memories in survivors of road traffic accidents

We investigated the trauma narratives of 131 road traffic accident survivors prospectively, at 1 week, 6 weeks, and 3 months post-trauma. At 1 and 6 weeks, narratives of survivors with acute stress disorder (ASD) or post-traumatic stress disorder (PTSD) were less coherent and included more dissociation content. By 3 months, their narratives also contained more repetition, more non-consecutive chunks, and more sensory words. Traumatic brain injury was associated with a separate characteristic, confusion, at all three time points. Three aspects of narrative organisation at 1 week--repetition, non-consecutive chunks, and coherence--predicted PTSD severity at 3 months after controlling for initial symptoms. The results suggest both a strong concurrent and predictive relationship between narrative disorganisation and ASD/PTSD but that as people recover from ASD, their narratives do not necessarily become less disorganised.