Septal area lesions impair spatial working memory in homing pigeons (Columba livia)

The septo-hippocampal system in birds resembles that of mammals, motivating research into the function of the avian hippocampus while surprisingly little attention has been given to the septum. To investigate a possible role of the avian septum in memory, the effects of septal area lesions on a spatial working memory (SpWM) task was tested in homing pigeons. After preoperative training on an analogue eight-arm (feeders) radial maze, now sham-operated control and septal lesioned pigeons were then trained again on the same task of locating the four feeders on the test phase of a trial that were not baited during the sample phase of a trial. During the test phase of a working memory trial, septal lesioned pigeons, compared to both their own preoperative performance and the performance of the controls, required significantly more choices to locate the four baited feeders not baited during the sample phase of a trial, and they made significantly fewer correct responses to the now baited feeders on their first four choices. The results demonstrate that, like its mammalian counterpart, the avian septum plays an important role in SpWM, suggesting that at least some functional properties of the septum are evolutionarily conserved in birds and mammals.     

大脑皮层-背侧纹状体通路在吗啡强迫性觅药和用药行为中的作用

药物成瘾是以强迫性觅药和用药行为为核心特征的慢性脑疾病。从初始用药到强迫性用药是成瘾者的觅药行为从目标导向性向习惯化发展的过程。强迫性觅药和用药行为是依赖于背外侧纹状体的习惯化行为, 同时前额叶皮层-背内侧纹状体通路对行为的控制减弱, 导致感觉运动皮层-背外侧纹状体通路对行为的控制持续占主导地位, 是成瘾行为具有强迫性特征的重要神经基础。本项目围绕这一重要问题展开研究, 在建立具有成瘾特征的动物模型的基础上, 采用行为学、行为药理学和组织形态学等方法揭示皮层-纹状体通路在强迫性觅药和用药行为中的作用。研究结果有望为进一步寻找该神经网络参与成瘾行为的分子机制提供重要线索。     

右腹外侧前额叶对高抑郁水平成年人社会情绪调节的作用：一项tDCS研究

已有的经颅直流电刺激(transcranial direct current stimulation, tDCS)研究证明, 右腹外侧前额叶(right ventrolateral prefrontal cortex, RVLPFC)是社会情绪调节的重要脑区, 激活RVLPFC可显著降低人们对社会性负性情绪体验的强度。社会功能受损是抑郁症患者或抑郁倾向人群的重要特征之一。该群体对社会排斥的敏感性高, 且对负性社会情绪体验的情绪调节能力降低。在本研究中, 我们采用外显的情绪调节任务, 研究了高、低抑郁水平的两组成年人被试在RVLPFC接受阳性tDCS后其情绪调节能力的改变。结果表明, 虽然采用tDCS激活RVLPFC可帮助被试通过情绪调节(认知重评)减弱负性情绪体验, 但高抑郁水平被试的负性情绪强度下降程度明显小于低抑郁水平被试。另外本文还发现, 与源于个人的负性情绪相比, tDCS效应对源于社会的负性情绪(即社会排斥)更强。本研究是采用电或磁刺激提高抑郁人群社会情绪调节能力的首次尝试。实验结果表明, 高抑郁水平成年人的RVLPFC仅通过单次、短时间(34 min)的tDCS激活, 其情绪调节能力并未得到显著提升。这提示对抑郁倾向群体或抑郁症患者的干预或治疗需要多次施加tDCS。     

强迫性特征在药物成瘾行为中的易感性及其前额叶-反奖赏系统神经基础

强迫性是一种与不顾严重后果的固着行为密切相关的神经心理结构, 大脑神经系统对强迫性行为的调控机制崩溃是导致药物成瘾的直接原因。以往研究对于奖赏系统(中脑-皮层-边缘神经环路)在成瘾行为中的作用及机制已经具有丰富的了解, 但针对药物成瘾的强迫性特征本身以及前额叶-反奖赏系统神经环路在成瘾行为中的作用机制了解有限, 尤其是缺乏对药物成瘾强迫性特征的系统考察、缺少遗传学研究以及非兴奋剂类药物的汇聚证据。项目拟结合人类成瘾行为的遗传学视角(海洛因成瘾者与其无药物使用的兄弟姐妹对照), 结合神经认知、脑电生理、神经影像等不同层面的方法和技术, 对药物成瘾强迫性的外在表征、神经生物学基础以及与个体差异有关的遗传易感性进行探索, 期在进一步识别药物成瘾的神经生物标记, 为探寻潜在的药物或非药物干预靶点提供更多证据。     

来源记忆与年老化

来源记忆不同于项目记忆,它更容易受年老化的影响,与这一现象有关的因素既有生理的又有心理的,前额皮层功能老化是影响老年人来源记忆的生理因素,而注意分配困难以及记忆加工困难是影响老年人来源记忆的两个重要心理因素。     

A Sex Difference on a Novel Spatial Working Memory Task in Humans

Neurophysiological and behavioral evidence suggests that the prefrontal cortex (PFC) may be sexually differentiated in nonhuman primates. The present study examined whether there are sex differences in working memory in humans that might reflect sexual differentiation of human PFC. Male and female undergraduates were administered a novel multitrial spatial working memory task (SPWM) and a verbal working memory task. In three experiments, females committed significantly fewer working memory errors and took significantly less time to reach criterion than males on the SPWM task. The female advantage was not accounted for by differences in general intellectual ability, attention, perceptual speed, incidental memory, or speed of verbal access. In Study 3, a sex difference was also observed on a measure of verbal working memory. The findings suggest that some prefrontal functions may be sexually differentiated in humans.     

Self-referential processing of negative stimuli within the ventral anterior cingulate gyrus and right amygdala

Neural activity associated with self-referential processing of emotional stimuli was investigated using whole brain functional magnetic resonance imaging (fMRI). Fifteen healthy subjects underwent fMRI scanning while making judgments about positive and negative trait words in four conditions (self-reference, other-reference, semantic processing, and letter processing). Significant activity was observed in the right ventral anterior cingulate gyrus and the right amygdala in the negative-word/self-reference condition, and in the left amygdala in the positive-word/self-reference condition. Compared with the semantic-processing condition, the self-reference conditions showed significantly more activity in the medial prefrontal and temporal gyri, posterior cingulate gyrus, and precuneus. These results suggest that the medial prefrontal gyrus, posterior cingulate gyrus, and precuneus are associated with a self-referential processing, and the ventral anterior cingulate gyrus is involved in self-referential processing of negative emotional stimuli. The results also suggest that the amygdala is associated with self-referential processing of both positive and negative emotional stimuli.     

The neural evidence for simulation is weaker than I think you think it is

Simulation theory accounts of mind-reading propose that the observer generates a mental state that matches the state of the target and then uses this state as the basis for an attribution of a similar state to the target. The key proposal is thus that mechanisms that are primarily used online, when a person experiences a kind of mental state, are then co-opted to run Simulations of similar states in another person. Here I consider the neuroscientific evidence for this view. I argue that there is substantial evidence for co-opted mechanisms, leading from one individual’s mental state to a matching state in an observer, but there is no evidence that the output of these co-opted mechanisms serve as the basis for mental state attributions. There is also substantial evidence for attribution mechanisms that serve as the basis for mental state attributions, but there is no evidence that these mechanisms receive their input from co-opted mechanisms.     

急性应激影响工作记忆的生理心理机制

急性应激是机体面对外界环境变化所产生的一系列生理和心理反应, 对认知加工, 尤其是核心的工作记忆能力产生深远影响, 然而以往的研究存在大量不一致的结果。从应激诱发方式、工作记忆加工子成分、个体差异等三个方面系统阐释应激影响工作记忆的生理心理机制, 并结合认知神经机制的框架, 可以更好地理解以往的结果。未来研究应综合考虑应激诱发、认知任务和响应个体等方面的差异对应激带来的影响, 并关注急性应激负面影响的干预与调控。