Department of Psychology, Louisiana State University, 236 Audubon Hall, Baton Rouge, LA, 70803, USA.
Brain Struct Funct. 2019 Dec;224(9):3309-3320. doi: 10.1007/s00429-019-01974-x. Epub 2019 Oct 31.
Trait neuroticism refers to individual differences in negative emotional response to threat, frustration, or loss, operationally defined by elevated levels of irritability, anger, sadness, anxiety, worry, hostility, self-consciousness, and vulnerability to mental and physical difficulties. While functional studies have been fairly consistent when identifying regions associated with neuroticism during emotional stimuli, structural imagining studies do not tend to find a relationship between amygdala volume and trait neuroticism. There is a great deal of functional evidence that frontoparietal areas are related to the amygdala, and to emotional reactivity more generally, as a function of their involvement in emotion regulation. Specifically, top-down emotion appraisal and expression appear to involve parts of the dorsolateral and dorsomedial prefrontal cortices, which operate at least in part via the indirect modulation of the amygdala. It was hypothesized that cortical surface area and cortical thickness in regions associated with emotion appraisal/expression and emotional attention (i.e., superior frontal and rostral middle frontal gyri, respectively) would have an indirect effect on the relationship between amygdala volume and self-reported neuroticism (respectively), potentially explaining the inconsistency in the structural literature. In sample of 1106 adults, superior frontal and rostral middle frontal gyri, as parcellated by Freesurfer, were examined as potentially restricting variance in a model of indirect effects, which may elucidate the overall relationship between cortical and subcortical gray matter volume and trait neuroticism. Results indicated that, despite no association between bilateral amygdala volume and trait neuroticism, when right superior frontal surface area was entered into the model of indirect effects, a significant relationship between amygdala volume and trait neuroticism emerged. Two of the three remaining models indicated that cortical surface area had an indirect effect on the relationship between amygdala volume and trait neuroticism. These findings highlight the relationship between structural and functional neuroimaging studies. Specifically, the results indicate that when volume is related to behavior, individual differences in higher-order cortical regions, particularly surface area, may help to better understand the relationship between emotion and subcortical gray matter volume.
特质神经质是指个体对威胁、挫折或损失的消极情绪反应的差异，其操作性定义为易激惹、愤怒、悲伤、焦虑、担忧、敌意、自我意识以及易患心理和身体疾病。虽然在识别情绪刺激过程中与神经质相关的区域的功能研究相当一致，但结构成像研究并不倾向于发现杏仁核体积与特质神经质之间的关系。有大量功能证据表明，额顶区域与杏仁核以及更一般的情绪反应有关，这是它们参与情绪调节的功能。具体来说，自上而下的情绪评估和表达似乎涉及背外侧和背内侧前额皮质的部分区域，这些区域至少部分通过间接调节杏仁核来运作。假设与情绪评估/表达和情绪注意相关的区域（即额上回和额中回的前上部）的皮质表面积和皮质厚度会对杏仁核体积与自我报告的神经质之间的关系产生间接影响（分别），这可能解释了结构文献中的不一致性。在 1106 名成年人的样本中，使用 Freesurfer 对额上回和额中回的前上部进行分割，作为间接效应模型中限制方差的变量进行了检查，这可能阐明了皮质和皮质下灰质体积与特质神经质之间的整体关系。结果表明，尽管双侧杏仁核体积与特质神经质之间没有关联，但当右侧额上回表面积进入间接效应模型时，杏仁核体积与特质神经质之间出现了显著的关系。三个剩余模型中的两个表明，皮质表面积对杏仁核体积与特质神经质之间的关系有间接影响。这些发现强调了结构和功能神经影像学研究之间的关系。具体来说，结果表明，当体积与行为相关时，高级皮质区域的个体差异，特别是表面积，可能有助于更好地理解情绪与皮质下灰质体积之间的关系。
