光照对小鸡脑内神经细胞粘附分子表达的影响

胚胎发育晚期光照条件的不同,对小鸡后天的学习记忆能力有显著的影响,暗孵化小鸡表现出明显的长时记忆障碍。实验利用免疫组化的方法,分别对光孵化、正常孵化和暗孵化条件下,胚胎发育的第17、18、19、20、21天,小鸡脑内上纹体腹核(HV)中神经细胞粘附分子(NCAMs)的表达进行了观察。结果表明：暗孵化条件下孵出的小鸡,在一次性被动回避学习中,记忆保持水平显著低于光孵化组和正常孵化组;在胚胎发育的第20天NCAM的表达,在光孵化组和正常孵化组中显著增高,到胚胎发育的第21天,这种升高在正常孵化组中显著下降;而暗孵化组在整个观察过程中,NCAM表达水平一直非常低。这一结果提示,不同光照条件在孵化过程中,对NCAM表达的影响,参与了光照对小鸡后天学习记忆行为改变的过程。     

对语言神经机制的新认识

本文针对语言神经机制的研究现状,分析了失语症和裂脑人研究的成果,并且较为详细地介绍了最近十年脑功能成像得到的有关语言神经活动的新成就,在此基础上,提出了一种动态分布式竞争的解释理论,用来解释语言神经活动现象和规律,并进一步借以说明言语意识的产生机制。     

基于神经网络的黑白图形视觉识别机制模拟

物理刺激引起视觉系统的生理反应．经过大脑的信息加工而形成视觉。现有多种模型从不同角度对视觉机制进行模拟。该文利用人工神经网络技术对黑白图形识别的视觉机制加以模拟,构建了一个两层BP(back-propagatbn)神经网络模型。应用所建网络对一幅目标和背景灰度分布曲线有重叠的图像进行了成功识别．对大脑视觉加工机制作了有益的探索。     

痛苦共情的功能性核磁共振成像研究述评

对他人痛苦的共情是指自动模拟受痛者的情感和运动状态,以及在自我-他人区分的基础上替代性地分享和理解他人由于受痛所引发的情绪状态.痛苦共情的fMRI研究常用图片诱导范式和线索诱导范式.痛苦共情的神经机制,包括(1)疼痛矩阵(该区域在个体自身受痛时也会激活)和(2)观点采择的相关脑区.痛苦共情的水平会受到实验范式和任务,以及共情者对于受痛者态度两方面因素的共同影响.加强应用研究和推出新型范式是痛苦共情研究的当务之急.     

Interfacing the Somatosensory System to Restore Touch and Proprioception: Essential Considerations

ABSTRACT

State-of-the-art upper extremity prostheses include anthropomorphic hands with dexterity that approximates that of a human. To be fully useful, these devices will require an advanced somatosensory neural interface to convey tactile and proprioceptive feedback to the user. To this end, microstimulation methods are being developed using microelectrode arrays implanted at various locations along the somatosensory neuraxis, from peripheral nerves to primary somatosensory cortex. There is presently no consensus as to the best approach, although results from animal and human studies lend support for each. The purpose of this review is to outline practical considerations for the design of a somatosensory interface based on present knowledge of the anatomy and physiology, prior attempts to elicit somatic sensations using electrical stimulation, and lessons learned from successful sensory neuroprostheses such as the cochlear implant.     

Editorial to the special issue Neuronus

Did you visit the Neuronus conferences in the years 2012 and 2013 in Kraków? If not, then you certainly should have a close examination of this special issue including this introduction to at least have a glimpse of an idea of the highly interesting topics in the field of cognitive neuroscience that were presented at these conferences. If you were there, it is for sure a good choice to focus on this special issue as well, first to refresh your minds (we know our memories are far from perfect), but especially to see what happened with research of the presenters at these conferences.     

情绪对注意功能网络的调制

情绪性注意是一种对具有情绪意义的刺激进行选择和加工的注意.由于刺激的情绪效价能调制人脑的感知和注意系统,因而,与对中性刺激的注意相比,情绪性注意的神经机制更加复杂.较早的研究显示,杏仁核对感知皮层的调制对情绪性注意起关键作用.近期的证据表明,杏仁核对注意功能网络的调制可能是其重要的神经机制.本文梳理了相关领域的研究证据,主要强调情绪性刺激对注意的警觉、定向和执行控制网络的调制,发现情绪性注意加工的认知神经机制可能涉及一个以杏仁核为核心的多重功能网络.     

时距知觉的扭曲:新异刺激效应

时距知觉会受到刺激新异性的影响,新异刺激的呈现时间往往被认为长于等时距重复出现的标准刺激的呈现时间.已有研究在解释这种主观的时距扩张现象时主要涉及三种假设:注意假设、唤醒假设和神经编码效能假设.研究中的变量混淆问题、跨通道效应和时间因素是今后研究中值得思考的几个问题.对于新异刺激效应产生的心理和神经机制,研究者们还存在着较大分歧.进一步探讨其心理和神经机制对理解时距知觉具有重要意义.     

Higher Processes in Motor Learning

A linear displacement task was used to study the effects of post-KR verbal activity and the time of its introduction in the learning process on the acquisition of a simple discrete motor task. The temporal occurrence of the interpolated act was systematically varied (3 and 10 sec. immediately following KR). Reading polysyllables during the post-KR delay interval interfered with the learning process. Interference occurred whether the post-KR delay interval lasted 3 or 10 sec.