Working memory improvement with non-invasive brain stimulation of the dorsolateral prefrontal cortex: A systematic review and meta-analysis

Recent studies have used non-invasive brain stimulation (NIBS) techniques, such as repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS), to increase dorsolateral prefrontal cortex (DLPFC) activity and, consequently, working memory (WM) performance. However, such experiments have yielded mixed results, possibly due to small sample sizes and heterogeneity of outcomes. Therefore, our aim was to perform a systematic review and meta-analyses on NIBS studies assessing the n-back task, which is a reliable index for WM. From the first data available to February 2013, we looked for sham-controlled, randomized studies that used NIBS over the DLPFC using the n-back task in PubMed/MEDLINE and other databases. Twelve studies (describing 33 experiments) matched our eligibility criteria. Active vs. sham NIBS was significantly associated with faster response times (RTs), higher percentage of correct responses and lower percentage of error responses. However, meta-regressions showed that tDCS (vs. rTMS) presented only an improvement in RT, and not in accuracy. This could have occurred in part because almost all tDCS studies employed a crossover design, possibly due to the reliable tDCS blinding. Study design was also associated with no improvement in correct responses in the active vs. sham groups. To conclude, rTMS of the DLPFC significantly improved all measures of WM performance whereas tDCS significantly improved RT, but not the percentage of correct and error responses. Mechanistic insights on the role of DLPFC in WM are further discussed, as well as how NIBS techniques could be used in neuropsychiatric samples presenting WM deficits, such as major depression, dementia and schizophrenia.     

一期颈椎后前路手术治疗伴有后凸畸形的多节段颈椎管狭窄的临床研究

为了研究与探讨一期颈椎后前路联合手术治疗伴有后凸畸形的多节段颈椎管狭窄的临床疗效,回顾性研究2011年3月至2013年2月在我院由同一组外科医生治疗且符合标准纳入研究的患者32例,比较术前与术后的 JOA 评分,颈髓功能改善率,Borden 氏测量法的 D 值,Vas 评分,评估一期颈椎后前路联合手术治疗该疾病的临床疗效。患者术后均随访12个月,患者接受一期后前路手术治疗后双臂双手麻木、间歇性跛行、走路有踩棉花感、肢体感觉障碍症状均有明显改善。一期颈椎后前路联合手术治疗伴有后凸畸形的多节段颈椎管狭窄症,可有效地矫正颈椎的后凸畸形,恢复颈椎正常的生理弯曲,解除颈髓压迫,恢复颈椎生理曲度,是安全有效的手术方法。     

努力控制及其神经基础

本文对努力控制的概念、发展及其神经基础进行了归纳和总结。我们发现努力控制涉及的脑区主要包括背外侧和腹外侧前额叶,前扣带回,顶上和顶下小叶以及辅助运动皮层等。此外,通过分析对比后发现努力控制与执行功能之间在行为表现和神经基础上有密切关系：两者都与个体的学业成绩、情绪状态和攻击行为等有关;努力控制涉及的脑区有很大部分处于具有执行功能的突显网络和额顶控制网络。这些证据表明两者之间可能有共同的脑结构基础。     

Developmental imaging genetics: Linking dopamine function to adolescent behavior

Adolescence is a period of development characterized by numerous neurobiological changes that significantly influence behavior and brain function. Adolescence is of particular interest due to the alarming statistics indicating that mortality rates increase two to three-fold during this time compared to childhood, due largely to a peak in risk-taking behaviors resulting from increased impulsivity and sensation seeking. Furthermore, there exists large unexplained variability in these behaviors that are in part mediated by biological factors. Recent advances in molecular genetics and functional neuroimaging have provided a unique and exciting opportunity to non-invasively study the influence of genetic factors on brain function in humans. While genes do not code for specific behaviors, they do determine the structure and function of proteins that are essential to the neuronal processes that underlie behavior. Therefore, studying the interaction of genotype with measures of brain function over development could shed light on critical time points when biologically mediated individual differences in complex behaviors emerge. Here we review animal and human literature examining the neurobiological basis of adolescent development related to dopamine neurotransmission. Dopamine is of critical importance because of (1) its role in cognitive and affective behaviors, (2) its role in the pathogenesis of major psychopathology, and (3) the protracted development of dopamine signaling pathways over adolescence. We will then focus on current research examining the role of dopamine-related genes on brain function. We propose the use of imaging genetics to examine the influence of genetically mediated dopamine variability on brain function during adolescence, keeping in mind the limitations of this approach.     

前额叶的无创神经干预对饮食控制的影响:基于rTMS和tDCS研究的综述

饮食控制缺陷可导致超重、肥胖和饮食失调。已有研究表明,肥胖和饮食失调者在前额叶认知控制神经环路上存在缺陷。无创神经干预-经颅直流电刺激(t DCS)和重复经颅磁刺激(r TMS)-通过调节前额叶皮层兴奋性来提高饮食控制能力,改善饮食失调症状。未来的研究应考虑不同刺激参数和刺激位点下的干预效应,融合其他神经生理技术考察无创神经干预改善饮食控制的作用机制,考虑个体差异性并结合客观的行为范式进行探究。     

Timing matters! The neural signature of intuitive judgments differs according to the way information is presented

One can conceive of intuition as the preliminary perception of coherence. Since this requires holistic perception, it is hypothesized that underlying processing strategies are dependent on the possibility to obtain all relevant information at once. The present study used magnetoencephalography (MEG) to investigate neural mechanisms underlying intuitive coherence perception when semantic concepts are presented all together (simultaneously) or one after the other (sequentially). With simultaneous presentation, absolute activation increases in the left OFC when participants recognize coherence. With sequential presentation activation increases in the right OFC when participants conclude that there is no common associate between the words presented. Behavioral performance was similar in the two experiments. These results demonstrate that the way information is revealed over time changes the processing of intuitive coherence perception. We propose that such changes must be taken into account to disentangle the neural and behavioral mechanisms underlying different accounts of intuition and related phenomena.