Environmental enrichment improves behavioral performance and auditory spatial representation of primary auditory cortical neurons in rat

Environmental enrichment (EE) has an important role in brain plasticity. Early research has shown that EE increases the response strength of neurons in the auditory cortex, but it remains unknown whether EE can influence the process of spatial localization in the auditory system. In this study, we raised rats in enriched and standard conditions from postnatal day 10 to day 56. By testing behavioral tasks via auditory cues, we have shown that EE improved the number of correct scores, but decreased the reaction time and azimuth deviation in behavioral performance of sound-azimuth discrimination. By in vivo extracellular recording, we have shown that EE enhanced the directional sensitivity of neurons in the primary auditory cortex. For example, EE rats had a smaller spatial receptive field, sharper frequency tuning curve and directional selective curve of auditory neurons compared with normal rats. Our findings indicate that early exposure to EE increases directional sensitivity. These results provide an insight into developmental plasticity in the auditory system.     

Dogs recall their owner's face upon hearing the owner's voice

We tested whether dogs have a cross-modal representation of human individuals. We presented domestic dogs with a photo of either the owner's or a stranger's face on the LCD monitor after playing back a voice of one of those persons. A voice and a face matched in half of the trials (Congruent condition) and mismatched in the other half (Incongruent condition). If our subjects activate visual images of the voice, their expectation would be contradicted in Incongruent condition. It would result in the subjects’ longer looking times in Incongruent condition than in Congruent condition. Our subject dogs looked longer at the visual stimulus in Incongruent condition than in Congruent condition. This suggests that dogs actively generate their internal representation of the owner's face when they hear the owner calling them. This is the first demonstration that nonhuman animals do not merely associate auditory and visual stimuli but also actively generate a visual image from auditory information. Furthermore, our subject also looked at the visual stimulus longer in Incongruent condition in which the owner's face followed an unfamiliar person's voice than in Congruent condition in which the owner's face followed the owner's voice. Generating a particular visual image in response to an unfamiliar voice should be difficult, and any expected images from the voice ought to be more obscure or less well defined than that of the owners. However, our subjects looked longer at the owner's face in Incongruent condition than in Congruent condition. This may indicate that dogs may have predicted that it should not be the owner when they heard the unfamiliar person's voice.     

17β-Estradiol: Effect on CA1 Hippocampal Synaptic Plasticity

An understanding of synaptic plasticity in the mammalian brain has been one of R. F. Thompson's major pursuits throughout his illustrious career. A current series of experiments of significant interest to R. F. Thompson is an examination of the interactions between sex hormones, synaptic plasticity, aging, and stress. This research is contained within a broader project whose aim is to investigate animal models that evaluate estrogen interactions with Alzheimer's disease. This paper reviews the recent results that have led to a better understanding of how the sex hormone estrogen influences synaptic plasticity in an important structure within the mammalian brain responsible for learning and memory: the hippocampus. In this review, a number of experiments have been highlighted that investigate the molecular mechanisms that underlie estrogen's effect on two specific forms of synaptic plasticity commonly studied in neurophysiology and the behavioral neurosciences: long-term potentiation and long-term depression.     

长期高策略性技能训练对运动员大脑白质结构的影响：一项DTI研究

目前关于运动员经验优势的脑机制还存在争议, 尤其对于涉及较多认知过程参与的高策略性技能项目运动员, 其大脑白质结构可塑性变化还需进一步探究。研究横向对比了乒乓球运动员和非运动员大脑白质纤维束的弥散张量成像数据。结果发现, 相比于非运动员, 乒乓球运动员在连接背侧和腹侧通路脑区的双侧皮质脊髓束、左侧上纵束、左侧下纵束和双侧额枕下束的各向异性值(FA)更大, 进一步分析发现, 部分腹侧通路白质纤维束FA增加的原因是径向扩散系数(RD)下降。研究结果支持了动作双通路模型。提示经过长期高策略性技能训练, 乒乓球运动员在背侧和腹侧通路上的白质纤维束结构完整性增强。     

双眼视差的神经机制与知觉学习效应

双眼瞳距使得空间某物体在左右眼视网膜的成像存在微小位置差异, 这种差异被称为双眼视差(binocular disparity), 是立体视知觉的重要信息来源。对双眼视差的心理物理学研究始于18世纪初, 迄今已有接近两百年的历史。近年来, 双眼视差研究主要集中在两方面。其一是用电生理、脑成像技术考察双眼视差在视觉背、腹侧通路的模块化表征, 其脑区表征反映出视觉系统的层级式、平行式加工规律。其二是应用知觉学习范式研究双眼视差的可塑性。未来研究应综合脑成像和神经调控技术考察双眼视差的神经机制及其学习效应, 包括双眼视差与多种深度线索间的信息整合和交互作用。应用方向上, 可结合虚拟现实等技术优化训练范式, 实现立体视力的康复和增强。     

身体拥有感及其可塑性：基于内外感受研究的视角

身体自我表征中的身体拥有感(即我的身体属于我的感受)问题一直是自我意识研究的核心话题。大量的已有研究表明, 身体拥有感的体验涉及不同感官信号的整合, 当前大多数研究只重视视觉、触觉等外感受的作用, 一方面忽视了内感受的作用, 另一方面也缺乏对两类感受整合的关注。橡胶手错觉实验和身体障碍患者身上所表现出的外感受和内感受对身体拥有感的影响支持了身体拥有感的可塑性假设, 自由能量原理认为身体拥有感形成的基础是大脑不断评估更新可能性表征来维持稳定。未来的研究需要从改善内感受的测量和刺激呈现方法, 探索影响内感受的高阶认知因素以及关注某些神经症患者的内感受等方面寻求突破。     

反应抑制的训练:内容、效果与机制

近期的研究发现,个体的反应抑制能力具有一定的可塑性。研究者多采用双盲随机对照实验设计,训练的对象包括儿童、成人和特殊群体,研究者通过Go/Nogo、Stop-signal等任务进行为期1周至3周,45至7200试次不等的抑制控制能力训练,并结合行为、脑电以及脑成像等技术对训练效果进行评估,研究结果发现,接受了抑制控制训练的个体其抑制能力得到提升,并伴随脑神经活动的变化。另外,研究者发现,抑制控制能力的训练效果还可以迁移至个体日常生活中的表现。但是,也有些研究并未发现抑制控制训练的效果。训练任务的设置,评估任务的选择以及被试反应策略的差异等因素可能会影响训练的效果。抑制控制训练引发行为与大脑活动的变化可能是由于训练导致了个体建立了自上而下有意识的抑制控制模式和自下而上的自动抑制模式。反应抑制和冲突抑制可塑性的比较,儿童与老年人抑制功能的训练以及训练效果的追踪研究将成为该领域日后研究的重点问题。     

自动情绪调节的神经机制及其可塑性

自动情绪调节无需意识决定、注意加工及有意控制, 改变着情绪轨迹。迄今为止, 研究仅限于证实其确能低耗高效地改变情绪过程, 尚未对其如何改变情绪过程进行研究。以自动情绪调节的神经机制作为研究对象具有可操作性, 可从行为和心理生理层面, 对自动情绪调节改变情绪过程的机制进行实验研究。研究问题包括：1)通过EEG技术检验自动情绪调节是否影响预备阶段行为反应倾向; 2)自动情绪调节对注意的注意觉醒、注意朝向和注意执行三个阶段的作用机制; 3)自动情绪调节对评价和反应的作用机制; 4)自动情绪调节的可塑性在脑活动上的体现。最终确定自动情绪调节的加工规律, 构建其预备-注意-评价-反应模型, 并为有效控制情绪紊乱和研究出高效的情绪调节干预方案提供理论和实证依据。     

前额叶在老年阶段的可塑性及相关机制

大量研究表明, 前额叶的结构和功能更容易受年老化影响; 然而, 近年来的研究发现, 前额叶的结构和功能在老年阶段具有一定的可塑性。对老年人进行认知训练, 能够延缓前额叶皮层厚度的萎缩, 提高白质完整性, 改善神经网络的功能连接和分化, 并可能通过调节多巴胺系统的活动改变前额叶皮质和皮质下结构的功能激活模式。有氧锻炼能够改善心脑血管功能, 保护和促进神经元的存活和生长, 引起前额叶灰质、白质体积的增加及功能激活的变化。认知训练与有氧锻炼等相结合的整合性训练不仅引起前额叶及相关认知功能的改变, 而且具有更好的生态学效度, 使老年人日常认知能力和生活质量得到提高。未来研究应采用多种技术手段, 从多个层面理解老年阶段前额叶的可塑性及相关机制; 加强对与前额叶关系密切的多种认知功能可塑性神经机制的研究; 并重视与整合性训练有关的前额叶可塑性。     

进化发展心理学：发展中的人类本性

进化发展心理学研究社会能力与认知能力发展背后的基因与环境机制,以及基因与环境机制在特定社会文化中的表现。进化发展心理学探讨的主要问题与设计到的主要概念包括：（1）自然选择在毕生发展的早期阶段发挥作用;（2）进化发展心理学特别重视适应在婴儿期及儿童期发展中的作用;（3）儿童期的延长有助于儿童学习人类社会的复杂性;（4）发展背景的方法可以用来理解成人外显行为的进化起源;（5）基因与环境因素相互影响约束个体发展;（6）认知能力与行为活动敏感于早期环境,但二者发展也具有可塑性