脑功能磁共振伦理学问题初探

本文概略介绍新兴的脑功能磁共振检查原理及其对人脑运作机制、人类精神活动的研究。讨论脑功能磁共振的临床技术是否完善、现阶段普及该技术是否可能和必要,以及进行脑功能磁共振检查可能引发的隐私权、歧视等伦理学问题,并探讨解决之道。     

图形型归纳推理的神经机制:一项fMRI研究

利用fMRI脑成像技术探讨图形型归纳推理的神经机制。设计了一种由图形形状和条纹方向描述的简单几何图形组成的归纳推理任务,这种图形型任务与以往研究中常用的语句型归纳推理任务是同质的。根据两个图形共享特征数量的不同设计了两种实验任务:共享两个特征(2T)和共享一个特征(1T),以休息基线(Rest)作为控制任务。2T和1T任务均为归纳推理任务,但2T任务包含知觉特征整合成分,而1T任务不包括。结果发现:与控制任务相比,归纳推理任务在前额区(BA6、9、11、46、47)、尾状核、壳核和丘脑等脑区有显著激活,反映了"前额皮层-纹状体-丘脑"通路在图形型归纳推理中的重要作用;图形型归纳推理中的知觉信息整合与右侧额下回(BA47)、双侧尾状核头部、壳核等脑区有关。     

基于神经生理学的疼痛测量

疼痛是一种受多重因素影响的复杂主观感受。临床上,疼痛测量主要依赖于患者的主观评价。然而,这种传统的疼痛测量方法具有多方面的局限。近年来,研究者借助生理记录、脑电和功能磁共振等技术,揭示疼痛的神经生理、心理机制,挖掘与疼痛相关的神经生理指标,进而构建有效、客观和精确的疼痛评价体系。在基础研究和临床实践中,这些技术有望弥补传统疼痛测量方法的不足,从而极大推动疼痛测量及其治疗等相关领域研究的发展。     

关键字母法对英文词汇记忆效能的制约因素初步研究

通过干预范式和中介刺激法,选择89名初中一年级学生为被试,采用一系列自编的材料和工具,初步探讨了关键字母法对英文词汇记忆效能的制约因素.结果表明:(1)无论从短期看,还是从长期看.难以识别关键字母,会在一定程度上制约关键字母法的效能,不过,该因素的制约作用并不显著;(2)无论从短期看.还是从长期看,无论为准确的回忆,还是为大致的回忆,难以提取关键字母释义是制约关键字母法的显著因素.中介刺激法,作为本研究的突出特征,试图继承和发展维果茨基所创立的双莺刺激法.     

Elucidating the neural correlates of egoistic and moralistic self-enhancement

Self-enhancement is the biasing of one’s view of oneself in a positive direction. The brain correlates of self-enhancement remain unclear though it has been reported that the medial prefrontal cortex (MPFC) may be important for producing self-enhancing responses. Previous studies have not examined whether the neural correlates of self-enhancement depend on the particular domain in which individuals are enhancing themselves. Both moralistic and egoistic words were presented to participants while transcranial magnetic stimulation (TMS) was applied to the MPFC, precuneus or in a sham orientation. Participants were asked to make decisions as to the words describing themselves, some of which were positive and some of which were negative. It was found the MPFC TMS significantly disrupted egoistic self-enhancement when TMS was delivered to the MPFC. Judgments involving moralistic words were not influenced by TMS. These data provide further evidence that MPFC is involved in self-enhancement, and that the role of MPFC may be selective in this regard.     

道德直觉加工机制的理论构想

认知和情绪因素在道德判断中的作用机制是社会认知神经科学研究中最具争议的热点问题之一。本文认为, 人类拥有一种普遍性的道德直觉, 它是一种可能同时包含道德知识和情绪情感的自动化加工系统, 决定人们对一个道德违反情境作出快速的判断。据此, 本文就如何深入揭示道德直觉的加工机制提出了研究构想, 研究将首先采用经颅磁刺激技术, 探索当认知功能受抑制后人们的道德加工的特点, 初步探索道德直觉存在的可能性; 然后采用事件相关电位技术, 从外显和内隐两个维度上探讨道德直觉的时程加工机制; 最后采用侧向化运动准备电位指标, 进一步探索道德直觉和基本厌恶情绪的分离。     

盆底结构MRI研究进展及思考

盆底结构精细复杂,传统的解剖学以尸检为依据,现代影像学则提供了活体观察功能形态的有效方法。盆底结构核磁共振成像研究的新进展,体现了医学技术创新的稳健性、后发性、综合性,其发展取决于现代科学技术的进步。因此影像医学工作者作为医学科技主体,只有具备综合型知识结构,才能更好地进行医学技术创新。     

Further evaluation of methods to identify matched stimulation

The effects of preferred stimulation on the vocal stereotypy of 2 individuals were evaluated in two experiments. The results of Experiment 1 showed that (a) the vocal stereotypy of both participants persisted in the absence of social consequences, (b) 1 participant manipulated toys that did and did not produce auditory stimulation, but only sound-producing toys decreased his vocal stereotypy, and (c) only noncontingent music decreased vocal stereotypy for the other participant, but sterotypy paradoxically increased when toys were presented with music. Using a three-component multiple schedule, the results of Experiment 2 showed that the vocal stereotypy of both participants remained below preintervention levels following the removal of auditory stimulation and that 1 participant's vocal stereotypy increased following the removal of contingent reprimands. These patterns suggest that auditory stimulation functioned as an abolishing operation for vocal stereotypy and reprimands functioned as an establishing operation for vocal stereotypy. Together, the two experiments provide a method for identifying alternative stimulation that may substitute for automatically reinforced behavior.     

Cortical Language Mapping in Epilepsy: A Critical Review

One challenge in dominant hemisphere epilepsy surgery is to remove sufficient epileptogenic tissue to achieve seizure freedom without compromising postoperative language function. Electrical stimulation mapping (ESM) of language was developed specifically to identify essential language cortex in pharmacologically intractable epilepsy patients undergoing left hemisphere resection of epileptogenic cortex. Surprisingly, the procedure remains unstandardized, and limited data support its clinical validity. Nevertheless, ESM for language mapping has likely minimized postoperative language decline in numerous patients, and has generated a wealth of data elucidating brain–language relations. This article reviews the literature on topographical patterns of language organization inferred from ESM, and the influence of patient characteristics on these patterns, including baseline ability level, age, gender, pathology, degree of language lateralization and bilingualism. Questions regarding clinical validity and limitations of ESM are discussed. Finally, recommendations for clinical practice are presented, and theoretical questions regarding ESM and the findings it has generated are considered.