Amygdala response to happy faces as a function of extraversion
Amygdala response to happy faces as a function of extraversion
复制标题
DOI：
10.1126/science.1068749
复制
发表时间：
2002-06-21
期刊：
影响因子：
56.9
通讯作者：
Gabrieli, JDE
中科院分区：
文献类型：
--
作者：
Canli, T;Sivers, H;Gabrieli, JDE
认知神经科学旨在通过表征个体之间的共同机制和个体差异来描述大脑行为关系的原理。这两种方法都与杏仁核的研究相关，杏仁核是处理情绪信号的关键结构 (1)。对恐惧面部表情的持续激活（2-4）可能反映了一种共同的神经机制，而对快乐面部表情的不一致激活（2-4）可能反映了外向性人格特征的个体差异（5），因为杏仁核对积极情绪场景的激活随着该特征的变化而变化（6）。我们使用功能磁共振成像 (fMRI) 来检查杏仁核对恐惧表达的激活是否与外向性无关，以及杏仁核对快乐表达的激活是否随外向性而变化 (7)。仅当参与者表达恐惧时，杏仁核才会显着激活（图 1，左）。快乐表达时杏仁核的激活与外向程度呈显着正相关（图 1，中和右）。相关簇的中心位于杏仁核，但延伸到钩回和海马区域。外向性和杏仁核激活快乐表达之间关系的特殊性通过三种方式得到支持：(i) 外向性与其他情绪（愤怒、恐惧和悲伤）表达的激活没有显着相关；(ii) 神经质与任何表达的激活都没有显着相关； (iii) 这种相关性是“五大”主要人格特征因素（外向性、神经质、开放性、宜人性和责任心）与所有四种面部表情之间所有可能相关性中最大的。研究结果表明杏仁核区域有两个过程。第一个是人们对恐惧表达的一致反应，这可能反映了检测潜在危险情况线索的重要性。作为外向性的函数，第二个过程在不同人中的参与程度不同，是对快乐表情的反应。这种激活是左偏的，即位于与积极情绪和接近相关行为相关的半球内（8），因此可能有助于与外向者的社交互动风格一致的行为。与第二个过程相关的可变性可以解释为什么先前的研究（没有控制人格）报告了不同的结果（2-4）。有限的空间分辨率无法确定这些过程是否差异定位于杏仁核亚核或参与处理面部表情的邻近区域 (4)。然而，目前的结果表明，人格特质会影响大脑对情感显着感知的某些反应，但不会影响其他反应。
Cognitive neuroscience aims to delineate principles of brain-behavior relations by characterizing both common mechanisms across, and individual differences among, individuals. Both approaches are relevant for the study of the amygdala, a critical structure for the processing of emotional signals (1). Consistent activation to fearful facial expressions(2–4) may reflect a shared neural mechanism, whereas inconsistent activation to happy facial expressions (2–4) may reflect individual differences in the personality trait of extraversion (5), given that amygdala activation to positive emotional scenes varies as a function of this trait (6). We used functional magnetic resonance imaging (fMRI) to examine whether amygdala activation to fearful expressions is independent of extraversion and whether amygdala activation to happy expressions varies with extraversion (7). Significant amygdala activation across participants was found only for fearful expressions (Fig. 1, left). Amygdala activation for happy expressions correlated positively and significantly with the degree of extraversion (Fig. 1, middle and right). The center of the correlation cluster was located in the amygdala but extended into regions of the uncus and hippocampus. The specificity of the relation between extraversion and amygdala activation to happy expressions was supported in three ways:(i) Extraversion did not correlate significantly with activation to other emotional (angry, fearful, and sad) expressions;(ii) neuroticism did not correlate significantly with activation to any expression; and (iii) this correlation was the largest of all possible correlations among the “big 5” major personality traits factors (extraversion, neuroticism, openness, agreeableness, and conscientiousness) and all four facial expressions. The findings suggest two processes in the amygdaloid region. The first is engaged consistently across people in response to fearful expressions and may reflect the importance of detecting cues to potentially dangerous situations. The second process is engaged variably across people, as a function of extraversion, in response to happy expressions. This activation was left-lateralized, ie, located within the hemisphere associated with positive emotions and with approach-related behavior (8), and may thus contribute to behavior consistent with the sociable interactive style of extraverts.The variability associated with this second process may explain why prior studies, which did not control for personality, reported various outcomes (2–4). Limited spatial resolution precludes determination of whether these processes are differentially localized among the subnuclei of the amygdala or adjacent regions involved in processing facial expressions (4). Nevertheless, the present results demonstrate that personality traits influence some, but not other, brain responses to emotionally salient perceptions.