Department of Psychology, UCLA, CA, USA.
Soc Cogn Affect Neurosci. 2009 Dec;4(4):328-39. doi: 10.1093/scan/nsp028. Epub 2009 Dec 17.
Sex differences in brain structure have been examined extensively but are not completely understood, especially in relation to possible functional correlates. Our two aims in this study were to investigate sex differences in brain structure, and to investigate a possible relation between orbitofrontal cortex subregions and affective individual differences. We used tensor-based morphometry to estimate local brain volume from MPRAGE images in 117 healthy right-handed adults (58 female), age 18-40 years. We entered estimates of local brain volume as the dependent variable in a GLM, controlling for age, intelligence and whole-brain volume. Men had larger left planum temporale. Women had larger ventromedial prefrontal cortex (vmPFC), right lateral orbitofrontal (rlOFC), cerebellum, and bilateral basal ganglia and nearby white matter. vmPFC but not rlOFC volume covaried with self-reported emotion regulation strategies (reappraisal, suppression), expressivity of positive emotions (but not of negative), strength of emotional impulses, and cognitive but not somatic anxiety. vmPFC volume statistically mediated sex differences in emotion suppression. The results confirm prior reports of sex differences in orbitofrontal cortex structure, and are the first to show that normal variation in vmPFC volume is systematically related to emotion regulation and affective individual differences.
大脑结构的性别差异已经得到了广泛的研究，但仍不完全清楚，尤其是与可能的功能相关性。我们在这项研究中的两个目的是研究大脑结构的性别差异，并研究眶额皮质亚区与情感个体差异之间的可能关系。我们使用基于张量的形态测量法从 117 名健康右利手成年人（58 名女性）的 MPRAGE 图像中估计局部脑体积，年龄为 18-40 岁。我们将局部脑体积的估计值作为因变量输入 GLM 中，控制年龄、智力和全脑体积。男性的左颞平面较大。女性的腹内侧前额叶皮质（vmPFC）、右侧外侧眶额皮质（rlOFC）、小脑以及双侧基底节区和附近的白质较大。vmPFC 而不是 rlOFC 体积与自我报告的情绪调节策略（重新评估、抑制）、积极情绪的表达（而不是消极情绪）、情绪冲动的强度以及认知但不是躯体焦虑相关。vmPFC 体积在统计学上介导了情绪抑制的性别差异。这些结果证实了先前关于眶额皮质结构的性别差异的报告，并且是第一个表明 vmPFC 体积的正常变化与情绪调节和情感个体差异有系统关联的研究。
