认知负荷对疼痛共情的影响:来自ERP研究的证据

先前研究表明,对他人的疼痛共情受到多种因素的调节。认知负荷对疼痛共情的调节作用尚无研究。本研究使用事件相关电位技术探究高低认知负荷对疼痛共情神经加工过程的影响。实验通过不同长度的数字串记忆任务,形成高/低两种认知负荷,要求被试在不同认知负荷条件下观看他人处于疼痛/不疼痛情境下的图片,同时记录被试的在观看图片时的EEG数据。通过比较不同条件下观看图片诱发的ERP成分发现:早期成分P2和N2上认知负荷水平与图片类型出现了显著的交互作用,即在高认知负荷下疼痛图片诱发的波幅与非疼痛图片诱发的波幅差异显著,而低认知负荷下两种图片诱发的波幅差异不显著。这表明认知负荷主要影响疼痛共情加工的早期、自动化加工阶段。相比较于低认知负荷条件下,在高认知负荷下他人的疼痛获得了更好的加工。     

字谜与远距离联想解决中认知成分的比较

采用自发顿悟范式,通过事件相关电位(ERPs)探讨字谜和远距离联想（RAT）两类顿悟问题解决中的认知差异。结果发现,两类任务的正确反应时均在4000ms左右;解决两类任务的初期都在170ms时出现了正成分,且两类任务在此成分上没有显著差异;在600~700ms内,字谜比RAT诱发了一个更正的ERP成分,主要激活了中后部的脑区;在按键前的800~400ms内,字谜较RAT在右前额诱发了更正的脑电成分。结果表明,字谜顿悟和RAT顿悟存在相似的加工过程,但在重构阶段和啊哈体验上存在差异;两类任务在解决问题时重构过程的不同可能是造成情绪体验差异的原因     

内倾特质个体的自我参照加工程度效应

采用事件相关电位技术和三类刺激的经典oddball范式,以内隐的方式探讨内倾特质个体的自我参照加工程度效应及其神经机制。实验发现,在P2的波幅上,在电极前部、前中部和中部位置高自我相关的刺激比其它刺激诱发了更大的P2波幅。在P2的潜伏期上,在电极前部、中部、和中后部位置高自我相关的刺激比其它刺激诱发了更短的潜伏期。在N2的波幅上,高自我相关名字比其它刺激在左脑所诱发了更大的P2的波幅;对比内倾型被试,中间型被试的高自我相关名字比其它刺激诱发了更大的N2的波幅。在N2的潜伏期上,高自我相关的刺激在全脑都比其它刺激诱发了更短的N2潜伏期,且中后部电极位置的潜伏期最短;两类人格被试的高自我相关名字比其它刺激诱发了更短的N2潜伏期,但中间型人格被试的潜伏期最短。在P3平均波幅上,高自我相关的刺激在全脑都比其它刺激诱发了更大的P3波幅,其中中部脑区效应最大。研究结果表明内倾特质个体的自我参照加工具有程度效应,但对比中间型个体,内倾特质个体的自我参照加工的程度效应更弱。     

简单心算中数学学习困难儿童的数字距离效应

采用事件相关电位(ERP)方法,以阿拉伯数字的简单心算为任务,考察数学学习困难儿童(MD)的数字距离效应。行为数据的结果表明:MD组没有出现数字距离效应,对照组儿童出现了数字距离效应。事件相关电位数据显示:与对照组相比,MD组N270的潜伏期更长;两组被试在N270的波幅和潜伏期上都没有表现出数字距离效应。研究结果表明:MD儿童对数量信息的空间表征存在缺陷。     

外框数目、线索数目和线索类型对返回抑制的影响

采用被试内重复测量设计和经典的线索—靶子实验范式,考查了外框数目（4和8）、线索数目（1和3）、不同线索类型（on-off线索（即线索出现后消失）、onset线索（即线索持续呈现））对返回抑制的影响,发现靶子潜在位置数目越多反应时越长,返回抑制量越小;线索数目越少反应时越长,返回抑制量越大;onset线索反应时长于on-off线索,onset线索产生的返回抑制量大于on-off线索。这表明空间工作记忆负载和记忆痕迹会影响返回抑制。     

Of Mice and Men: Equality and Animals

Can material Egalitarianism (requiring, for example, the significant promotion of fortune) include animals in the domain of the equality requirement? The problem can be illustrated as follows: If equality of wellbeing is what matters, and normal mice are included in this egalitarian requirement, then normal mice have a much stronger claim to resources than almost any human. This is because normal mice have a much stronger claim to resources than almost any human. This is because their wellbeing is much lower than that of normal humans. Thus, equality of wellbeing requires a massive shift of resources away from most humans to mice. This view, however, seems crazy. I explore this problem and propose a solution.     

Chronic violent video game exposure and desensitization to violence: Behavioral and event-related brain potential data

Numerous studies have shown that exposure to media violence increases aggression, though the mechanisms of this effect have remained elusive. One theory posits that repeated exposure to media violence desensitizes viewers to real world violence, increasing aggression by blunting aversive reactions to violence and removing normal inhibitions against aggression. Theoretically, violence desensitization should be reflected in the amplitude of the P300 component of the event-related brain potential (ERP), which has been associated with activation of the aversive motivational system. In the current study, violent images elicited reduced P300 amplitudes among violent, as compared to nonviolent video game players. Additionally, this reduced brain response predicted increased aggressive behavior in a later task. Moreover, these effects held after controlling for individual differences in trait aggressiveness. These data are the first to link media violence exposure and aggressive behavior to brain processes hypothetically associated with desensitization.     

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.     

右侧背外侧前额叶在视觉工作记忆中的因果性作用

以往的影像学研究表明右侧背外侧前额叶皮层(DLPFC)在视觉工作记忆中发挥重要作用, 然而缺乏因果性的证据。本研究旨在考察右侧DLPFC的激活与视觉工作记忆容量的因果关系, 并探讨这一关系受到记忆负荷的调节及其神经机制。被试接受经颅直流电刺激之后完成视觉工作记忆变化检测任务, 根据被试在虚假刺激情况下从负荷4到负荷6任务记忆容量的增量将被试分为低记忆增长潜力组(简称低潜力组)和高记忆增长潜力组(简称高潜力组), 结果发现正性电刺激右侧DLPFC相对于虚假电刺激显著提升了高潜力组被试在低记忆负荷(负荷4)下的记忆容量及其对应的提取阶段的脑电指标SPCN成分。表明右侧DLPFC在视觉工作记忆的提取阶段发挥重要的因果性作用; 正性经颅直流电刺激右侧DLPFC可使工作记忆容量高潜力被试获得更多的脑活动增益, 并导致更好的行为提升效果。     

网络成瘾者工作记忆能力的ERP研究

旨在探究网络成瘾者和非成瘾者在言语工作记忆任务和视觉工作记忆任务中,面对网络相关刺激与网络无关刺激的ERP成分差异。利用词汇和图片材料,招募网络成瘾者以及非成瘾者各30名参加了N-back（N=2）工作记忆任务的ERP实验,同时记录行为数据及EEG,离线处理数据。结果发现：（1）在视觉工作记忆任务中,与网络无关图片相比,两组被试对网络相关图片的反应时显著更长,正确率也显著更低,而在言语工作记忆中无此显著差异;（2）非成瘾者面对网络相关图片产生的N2波幅显著高于网络无关图片,网络成瘾者对网络相关图片产生的P3波幅显著高于网络无关图片。两组差异表明网络成瘾者在言语工作记忆和视觉工作记忆上对网络相关刺激的早期加工存在差异,网络成瘾者对网络相关图片的视觉工作记忆水平较低。