Department of Psychiatry and Behavioral Sciences, Center for Interdisciplinary Brain Sciences Research, Stanford University, Stanford, CA 94305-5795, USA.
Soc Neurosci. 2013;8(4):291-304. doi: 10.1080/17470919.2013.794751. Epub 2013 May 14.
The developmental origin of sex differences in adult brain function is poorly understood. Elucidating neural mechanisms underlying comparable cognitive functionality in both children and adults is required to address this gap. Humor appreciation represents a particularly relevant target for such developmental research because explanatory theories apply across the life span, and underlying neurocircuitry shows sex differences in adults. As a positive mood state, humor is also of interest due to sex differences in rates of depression, a disorder afflicting twice as many women as men. In this study, we employed functional magnetic resonance imaging (fMRI) to investigate brain responses to funny versus positive (and neutral) video clips in 22 children, ages 6-13 years, including eight sibling-pairs. Our data revealed increased activity to funny clips in bilateral temporo-occipital cortex, midbrain, and amygdala in girls. Conversely, we found heightened activation to positive clips in bilateral inferior parietal lobule, fusiform gyrus, inferior frontal gyrus, amygdala, and ventromedial prefrontal cortex in boys. Many of these effects persisted when looking at sibling-pairs only. We interpret such findings as reflecting the presence of early sex divergence in reward saliency or expectation and stimulus relevance attribution. These findings are discussed in the context of evolutionary and developmental theories of humor function.
性别对成年人大脑功能的影响的发展起源尚不清楚。为了填补这一空白，需要阐明儿童和成人在类似认知功能方面的神经机制。幽默欣赏是这种发展研究的一个特别相关的目标，因为解释理论适用于整个生命周期，并且潜在的神经回路在成年人中存在性别差异。作为一种积极的情绪状态，幽默也因其在抑郁症发病率上的性别差异而受到关注，这种疾病困扰着两倍于男性的女性。在这项研究中，我们使用功能磁共振成像（fMRI）技术研究了 22 名 6-13 岁的儿童对有趣的、积极的（和中性的）视频片段的大脑反应，其中包括 8 对兄弟姐妹。我们的数据显示，女孩的双侧颞顶叶皮层、中脑和杏仁核对有趣的片段反应增强。相反，我们发现男孩的双侧顶下小叶、梭状回、额下回、杏仁核和腹内侧前额叶对积极的片段反应增强。当只观察兄弟姐妹时，许多这些影响仍然存在。我们将这些发现解释为反映了奖励显著性或预期以及刺激相关性归因方面的早期性别差异的存在。这些发现将在幽默功能的进化和发展理论的背景下进行讨论。
