经颅直流电刺激在抑郁症治疗中的应用

已有的神经影像学研究成果揭示, 抑郁症发作的重要原因之一是大脑前额叶皮层结构和功能受损。经颅直流电刺激(tDCS)作为一种无创脑刺激, 选取前额叶皮层作为刺激区域, 通过调节皮层兴奋性来治疗抑郁症, 能够有效缓解抑郁症状和改善受损的认知功能, 疗效明显且持久稳定。针对tDCS在抑郁症治疗研究中的问题, 未来可从有效性、个体差异以及预防干预等六个方面进一步研究, 以期tDCS作为一种具有潜力的治疗手段, 在临床上有更为广泛地应用。     

基于非侵入性脑刺激的认知增强：方法、伦理和应用

作为人类追求卓越的方式之一,基于非侵入性脑刺激的认知增强成为众多学科和公众关注的问题。首先阐述了非侵入性脑刺激的两种主要技术手段(经颅磁刺激和经颅直流刺激)的技术原理及其在提升健康个体认知功能上的应用,并分析了这两种技术可能带来的安全、自主选择、公平等伦理问题,最后总结了该认知增强技术在体育和军事等两个具体领域的应用。未来可进一步提高技术手段的深部脑区刺激能力及该增强技术的持续和真实效果。     

The Effect of Paired Muscle Stimulation on Preparation for Movement

Paired muscle stimulation is used clinically to facilitate the performance of motor tasks for individuals with motor dysfunction. However, the optimal temporal relationship between stimuli for enhancing movement remains unknown. We hypothesized that synchronous, muscle stimulation would increase the extent to which stimulated muscles are concurrently prepared for movement. We validated a measure of muscle-specific changes in corticomotor excitability prior to movement. We used this measure to examine the preparation of the first dorsal interosseous (FDI), abductor digiti minimi (ADM), abductor pollicis brevis (APB) muscles prior to voluntary muscle contractions before and after paired muscle stimulation at four interstimulus intervals (0, 5, 10, and 75 ms). Paired muscle stimulation increased premovement excitability in the stimulated FDI, but not in the ADM muscle. Interstimulus interval was not a significant factor in determining efficacy of the protocol. Paired stimulation, therefore, did not result in a functional association being formed between the stimulated muscles. Somatosensory potentials evoked by the muscle stimuli were small compared to those commonly elicited by stimulation of peripheral nerves, suggesting that the lack of functional association formation between muscles may be due to the small magnitude of afferent volleys from the stimulated muscles, particularly the ADM, reaching the cortex.     

Bi-hemispheric anodal transcranial direct current stimulation worsens taekwondo-related performance

Transcranial Direct Current Stimulation (tDCS) is a neuromodulatory technique that has been used as an ergogenic aid in exercise/sports performance. However, little is known about its effects on highly-trained subjects, as athletes. The present study aimed to verify the effects of bi-hemispheric anodal tDCS (a-tDCS) on the performance of taekwondo athletes. Additionally, we investigated the persistence of the effects of the a-tDCS one hour after it. Nineteen Taekwondo athletes received active or sham bi-hemispheric a-tDCS over the primary motor cortex (M1). a-tDCS was delivered at 1.5 mA for 15 min. Athletes performed Countermovement Jumps (CMJ) and the Frequency Speed of Kick Test (FSKT) immediately (Mo1) and one hour after stimulation (Mo2). The athletes also reported their session-rating of perceived exertion (session-RPE). The total number of kicks (TK) was higher in sham than in the active a-tDCS condition (p < 0.01). In addition, TK was higher at Mo2 than at Mo1 (p < 0.05). Similarly, the session-RPE was higher in the a-tDCS condition (p < 0.05) and was greater one-hour post-stimulation (p < 0.01). No differences were found for CMJ performance (p > 0.05). Thus, bi-hemispheric a-tDCS worsens performance of taekwondo athletes, and the effect remains present even 1 h after the stimulation.     

自尊稳定性的认知神经机制

自尊稳定性(自尊在短期内波动的幅度)是一种具有重要心理功能的人格特质, 它既不同于自尊水平, 也区别于情境性自尊, 但在理论和测量上却与后两者具有密不可分的联系。然而, 由于目前人们对于自尊稳定性的认知神经机制知之甚少, 所以并不清楚它与自尊水平在生理机制上的关系是什么, 更不了解它会如何调节情境性自尊。鉴于此, 本研究计划将自尊稳定性、自尊水平和情境性自尊置于整合的认知神经加工模型(神经内分泌-脑-行为)之中, 通过融合心理测量、脑成像与应激诱发等多种技术指标, 力争全方位、多角度揭示自尊稳定性的认知神经机制, 及其与自尊水平、情境性自尊间的区别和联系。     

人脑自适应多尺度功能连接的性别差异

已有脑成像研究展示了男女脑功能差异, 但功能磁共振信号的频率划分通常基于主观经验, 使脑功能性别差异的生物学解释遭遇瓶颈。本文提出人脑自适应多尺度功能连接算法, 刻画功能连接的时空多尺度特性, 揭示出0.06~0.10 Hz的性别差异：男性较强的连接主要与边缘网络和腹侧注意网络有关, 女性较强的连接主要与腹侧注意网络、视觉网络和额顶网络有关。     

Intracranial self-stimulation improves memory consolidation in rats with little training

Post-training intracranial electrical self-stimulation can improve learning and memory consolidation in rats. However, the molecular mechanisms involved are not known yet. Since previous paradigms of this kind of facilitation are relatively unsuitable to try a molecular approach, here we develop a single and short model of learning and memory facilitation by post-training self-stimulation that could make easier the research of its neural and molecular basis. Thus, three consecutive experiments were carried out to ascertain whether post-training self-stimulation is able to facilitate memory when learning consists of only a brief (5 trials) two-way active avoidance conditioning session. The results of Experiment 1 showed that it is actually possible, and that 48 h after the acquisition session is a very good time to observe the memory improvement. As a way to probe the retroactive effect of self-stimulation, in Experiment 2 we observed that the same self-stimulation treatment given to the subjects not post-training but 48 h before a single two-way active avoidance session does not improve the acquisition of conditioning. In Experiment 3, we showed that the SS facilitative effect observed 48 h after the acquisition session in Experiment 1 was still maintained one week later. We concluded that post-training intracranial self-stimulation can consistently improve memory consolidation even when little acquisition training is given to the animals in a single training session.     

Persistent effects of subliminal stimulation: sex differences and the effectiveness of debriefing

Persistent and non-trivial effects of unconscious stimuli have been reported (Sohlberg & Birgegard, 2003). This raises the ethical question of whether informing participants about such stimuli effectively returns them to a normal state. Two experiments (sex-mixed, N = 70 and 118) tested two kinds of debriefing to participants following subliminal (tachistoscopic) attachment-related or control stimulation. Measures were the Beck Depression Inventory, Structural Analysis of Social Behavior, and Retrospective Attachment. Results showed persistent effects. Simple debriefing about the stimulus was effective in preventing these, while more elaborate debriefing also describing the effects and mechanisms for them was less effective. Persistent effects were also strongly related to participant sex, but debriefing effects were similar in men and women with regard to the purpose of debriefing. The findings have implications for ethical recommendations for subliminal research, and suggest that this unexplored area requires more attention.     

认知和情绪冲突的监控与解决：来自轻度认知损伤的证据

轻度认知损伤(mild cognitive impairment, MCI)是介于正常老化和痴呆之间的过渡阶段。近年来, 执行控制的损伤被认为是MCI的核心特征之一。当前, 在MCI执行控制的领域内, 对冲突监控与解决的特征及其神经机制的研究较少。本研究拟通过认知及情绪冲突实验范式, 结合脑成像技术, 探讨遗忘型MCI (amnestic MCI, aMCI)认知和情绪冲突的监控与解决的特征及相应的脑激活模式; 通过对比aMCI和正常老年人在认知和情绪冲突任务中激活的神经环路, 考察aMCI是否在执行加工的神经网络上存在激活异常。在上述研究基础上, 研究者拟探讨aMCI在执行控制的冲突监控与解决上是否存在一般性的损伤机制, 同时试图寻找aMCI在执行控制的冲突监控与解决方面的认知及神经生物学标记。这对深入理解痴呆的发病进程并有针对性的开展痴呆的早期识别与干预具有重要的理论意义和实践意义。     

Intersensory Redundancy Guides the Development of Selective Attention, Perception, and Cognition in Infancy

Abstract— That the senses provide overlapping information for objects and events is no extravagance of nature. This overlap facilitates attention to critical aspects of sensory stimulation, those that are redundantly specified, and attenuates attention to nonredundantly specified stimulus properties. This selective attention is most pronounced in infancy and gives initial advantage to the perceptual processing of, learning of, and memory for stimulus properties that are redundant, or amodal (e.g., synchrony, rhythm, and intensity), at the expense of modality-specific properties (e.g., color, pitch, and timbre) that can be perceived through only one sense. We review evidence supporting this hypothesis and discuss its implications for theories of perceptual, cognitive, and social development.