School of Psychology, University of Auckland, Auckland, New Zealand; Laboratory of Neuro Imaging, School of Medicine, University of Southern California, Los Angeles, CA, United States.
School of Psychology, University of Auckland, Auckland, New Zealand.
Handb Clin Neurol. 2020;175:3-11. doi: 10.1016/B978-0-444-64123-6.00001-1.
Research based on structural magnetic resonance imaging (MRI) has revealed a number of sex differences in the anatomy of the human brain. The first part of this chapter presents an excerpt of these findings discriminating among effects on a global, regional, and local level. While findings are far from consistent and conclusive, there is general consensus with respect to sex-specific brain size, with male brains being bigger on average than female brains. So, the question arises as to whether any of the observed sex differences are merely driven by brain size. The second part of this chapter thus sheds light on a unique scientific attempt to discriminate between brain size effects and sex effects. The overarching goal of this chapter is to exemplify the variety of findings and to demonstrate that the presence, magnitude, and direction of significant sex differences strongly depend on the measurement applied. The assumption that sex differences are simply a by-product of brain size, rather than pure (size independent) sex effects has proven to be true for some but certainly not all findings. Therefore, when examining the possible sexual dimorphism of the brain, it is imperative to avoid oversimplification and generalization.
基于结构磁共振成像（MRI）的研究揭示了人类大脑解剖结构中的许多性别差异。本章的第一部分介绍了这些发现的摘录，这些发现区分了全局、区域和局部水平的影响。虽然这些发现远非一致和结论性的，但对于男性大脑平均比女性大脑大的性别特异性大脑大小存在普遍共识。因此，就出现了这样一个问题，即观察到的性别差异是否仅仅是由大脑大小驱动的。本章的第二部分因此揭示了一项独特的科学尝试，旨在区分大脑大小效应和性别效应。本章的总体目标是举例说明各种发现，并表明显著的性别差异的存在、大小和方向强烈取决于所应用的测量方法。性别差异仅仅是大脑大小的副产品，而不是纯粹的（与大小无关的）性别效应的假设，对于一些发现是正确的，但肯定不是所有发现都是正确的。因此，在检查大脑可能存在的性别二态性时，避免过度简化和概括是至关重要的。
