飞机君新闻:攻击型人格新探

剑桥大学一项新的研究表明，人在没有进食，或承受较大的压力的情况下，大脑中的血清素水平会出现波动，以致影响到大脑中控制愤怒情绪的区域。

Although reduced serotonin levels have previously been implicated in aggression, this is the first study which has shown how this chemical helps regulate behaviour in the brain as well as why some individuals may be more prone to aggression. The research findings were published today, 15 September, in the journal Biological Psychiatry. 

尽管以往对攻击型人格的研究也涉及到血清素水平下降的问题，但对于解释该化学物质如何控制大脑行为，以及说明某些人为何更易患攻击型人格障碍等方面，这项研究尚属首次，刚刚于今天（9月15日）发表在《生物精神病学》（Biological Psychiatry）杂志上。

For the study, healthy volunteers' serotonin levels were altered by manipulating their diet. On the serotonin depletion day, they were given a mixture of amino acids that lacked tryptophan, the building block for serotonin. On the placebo day, they were given the same mixture but with a normal amount of tryptophan. 

研究中，受试人员身体状况良好，且都是自愿参加，他们通过控制饮食来改变自己的血清素水平。如果某天他们血清素水平下降，就服用不含色氨酸（血清素的基本组成因子）的复合氨基酸；如果某天进行安慰剂对照实验，他们依然服用同样的复合氨基酸，但里面含有标准量的色氨酸。

The researchers then scanned the volunteers' brains using functional magnetic resonance imaging (fMRI) as they viewed faces with angry, sad, and neutral expressions. Using the fMRI, they were able to measure how different brain regions reacted and communicated with one another when the volunteers viewed angry faces, as opposed to sad or neutral faces. 

接下来，研究人员让受试人员面对愤怒、悲伤、呆滞等各种表情，利用功能核磁共振成像技术扫描他们的大脑。该技术能判断出当受试人员面对愤怒的表情时，与面对悲伤或呆滞的表情相比较，他们大脑中各个区域的反应和交流有何异样。

The research revealed that low brain serotonin made communications between specific brain regions of the emotional limbic system of the brain (a structure called the amygdala) and the frontal lobes weaker compared to those present under normal levels of serotonin. The findings suggest that when serotonin levels are low, it may be more difficult for the prefrontal cortex to control emotional responses to anger that are generated within the amygdala. 

结果显示，与正常血清素水平相比，大脑血清素水平降低会使控制情绪的大脑边缘系统（即杏仁核）中的特定区域和大脑额叶部的交流变得不顺畅。这说明，血清素水平越低，大脑前额皮质越难控制杏仁核内产生的愤怒情绪。

Using a personality questionnaire, they also determined which individuals have a natural tendency to behave aggressively. In these individuals, the communications between the amygdala and the prefrontal cortex was even weaker following serotonin depletion. 'Weak' communications means that it is more difficult for the prefrontal cortex to control the feelings of anger that are generated within the amygdala when the levels of serotonin are low. As a result, those individuals who might be predisposed to aggression were the most sensitive to changes in serotonin depletion. 

通过人格问卷调查的方式，也可以判定哪些人天生有攻击型人格特质。这些人在血清素水平降低时，大脑杏仁核和前额皮质的交流较一般人更为不畅。交流不畅就意味着血清素水平降低时，前额皮质难以控制杏仁核内产生的愤怒情绪。因此，具有攻击型人格倾向的人对血清素水平的降低反应最为敏感。

Dr Molly Crockett, co-first author who worked on the research while a PhD student at Cambridge's Behavioural and Clinical Neuroscience Institute (and currently based at the University of Zurich) said: "We've known for decades that serotonin plays a key role in aggression, but it's only very recently that we've had the technology to look into the brain and examine just how serotonin helps us regulate our emotional impulses. By combining a long tradition in behavioral research with new technology, we were finally able to uncover a mechanism for how serotonin might influence aggression." 

摩利·克罗凯特（Molly Crockett）博士是该研究的发起人之一。他致力于该项研究的时候，一位剑桥大学行为和临床神经学学院（现设在苏黎世大学）的博士生说：“几十年前我们就知道血清素对攻击型人格形成有重要作用，但是直到最近我们才有了能深入研究大脑的技术，才有办法了解血清素控制情绪的方式。把行为学悠久的研究传统和新技术结合起来，我们才能揭示血清素影响攻击型人格的内在机制。”

Dr Luca Passamonti, co-first author who worked on the research while a visiting scientist at the Cognition and Brain Sciences Unit of the Medical Research Council in Cambridge (and currently based at the Consiglio Nazionale delle Ricerche (CNR), Unità di Ricerca Neuroimmagini, Catanzaro), said: "Although these results came from healthy volunteers, they are also relevant for a broad range of psychiatric disorders in which violence is a common problem. For example, these results may help to explain the brain mechanisms of a psychiatric disorder known as intermittent explosive disorder (IED). Individuals with IED typically show intense, extreme and uncontrollable outbursts of violence which may be triggered by cues of provocation such as a facial expression of anger. 

卢卡·帕萨蒙提（Luca Passamonti）博士也是该研究的发起人之一。他致力于该项研究的时候，一位剑桥大学医学研究会认知和脑科学分会（现设在意大利卡坦扎罗Unità di Ricerca Neuroimmagini的CNR ）的访问学者说：“尽管研究中的受试人员都是身体健康的志愿者，但研究结果同样适用于很多精神疾病，其中包括狂暴症这种最普遍的疾病。例如，这些研究结果可以解释间歇性狂暴症（IED）的大脑运作机制。IED患者的典型表现就是紧张、极端和无法控制的暴力倾向，看到别人发怒，这种病症就会一触即发。”

"We are hopeful that our research will lead to improved diagnostics as well as better treatments for this and other conditions." 

“但愿我们的研究能有助于诊断学的发展，并为各种疾病提供更好的治疗方法。”

Funding: This study was supported by the James S. McDonnell Foundation 

资金来源：詹姆士·麦道尼尔（James S. McDonnell）基金会

21st Century Collaborative Award/Bridging Brain, Mind and Behavior (Award No. 22002015501) to E. A. Phelps and T. W. Robbins and completed within the Behavioural and Clinical Neuroscience Institute, which is cofunded by the Medical Research Council and the Wellcome Trust. Dr. Passamonti was funded by the Betty Behrens Research Fellowship at the Clare Hall College of the University of Cambridge. The J. S. McDonnell Foundation Network grant supported Dr. Apergis-Schoute. Dr. Crockett was supported by the National Science Foundation. 

菲尔普斯（E. A. Phelps）和罗宾斯（T. W. Robbins）因研究“大脑、心智和行为的关系”而获“21世纪合作奖”（获奖号：22002015501)，该研究在剑桥大学行为和临床神经学学院完成，并得到了医学研究会和威尔康姆（Wellcome）基金会的联合资助。帕萨蒙提博士得到了剑桥大学克莱尔·豪（Clare Hall）学院贝蒂·布莱恩（Betty Behrens）学术研究基金的资助。阿波吉·斯考特（Apergis-Schoute）博士得到了麦道尼尔基金联合会的资助。克罗凯特博士得到了国家科学基金会的资助。

Dr. Rowe was supported by the Wellcome Trust (Grant No. WT 088324); Dr. Calder by the Medical Research Council (Project Code MC_US_A060_0017). Development of the MacBrain Face Stimulus Set (NimStim) was overseen byNimTottenham and supported by the John D. and Catherine T. MacArthur Foundation Research Network on Early Experience and Brain Development.

罗威（Rowe）博士得到了威尔康姆基金会资助（资助编号：WT 088324）；卡尔德（Calder）博士获得剑桥大学医学研究会资助（项目代码：MC_US_A060_0017）。尼姆·托德汉姆（NimTottenham）负责“新一代大脑和面部刺激系统开发”（NimStim）项目，并获得约翰（John D. ）和凯瑟琳·马克阿瑟（Catherine T. MacArthur）基金联合会有关“早期经历和大脑开发”研究的资助。