Department of Psychology and Neuroscience, Boston College, Chestnut Hill, Massachusetts, USA.
Hippocampus. 2021 Jul;31(7):669-676. doi: 10.1002/hipo.23319. Epub 2021 Feb 25.
Sex differences in brain activity have been reported across various types of long-term memory. To our knowledge, sex differences in functional connectivity during long-term memory have not been investigated. A previous study on the structural connectome identified that female brains have a greater degree of interhemispheric connectivity than males, whereas males have a greater degree of intrahemispheric connectivity than females. The aim of the current investigation was twofold: (a) identify which brain regions were functionally connected to the hippocampus during spatial long-term memory, and (b) determine if there were sex differences in the functionally connected regions. During the study phase, abstract shapes were presented to the left or right of fixation. During the test phase, abstract shapes were presented at fixation and participants classified each item as previously on the "left" or "right". A hippocampal region of interest (ROI) was identified by contrasting spatial memory hits and misses. The peak coordinate from this ROI was used to define the center of a sphere that was used as the seed for the functional connectivity analysis. The connectivity analysis produced many connected activations including the medial posterior frontal cortex, lateral posterior frontal cortex, left inferior frontal gyrus, posterior cingulate cortex, and caudate/putamen. Although there were no regions with greater connectivity in females than males, the male versus female comparison produced connected activations in the medial posterior frontal cortex, anterior prefrontal cortex, precuneus, and cingulate sulcus. Females also had greater interhemispheric connectivity than males. The current findings suggest collapsing across sex in cognitive neuroscience studies may not be warranted.
已有研究报告称，在各种类型的长期记忆中，大脑活动存在性别差异。据我们所知，在长期记忆过程中，功能连接的性别差异尚未得到研究。先前的一项关于结构连接组学的研究表明，女性大脑的左右半球之间的连接程度比男性更大，而男性大脑的同侧半球内的连接程度比女性更大。本研究旨在：（a）确定在空间长期记忆过程中哪些大脑区域与海马体功能连接；（b）确定在功能连接区域是否存在性别差异。在研究阶段，向注视点的左侧或右侧呈现抽象形状。在测试阶段，向注视点呈现抽象形状，参与者将每个项目分类为之前的“左”或“右”。通过对比空间记忆的击中与错过，确定海马体感兴趣区（ROI）。该 ROI 的峰值坐标用于定义球体的中心，该球体用作功能连接分析的种子。连接分析产生了许多连接的激活，包括内侧后额叶皮层、外侧后额叶皮层、左侧额下回、扣带回后部和尾状核/壳核。尽管没有女性比男性连接更紧密的区域，但男性与女性的比较在内侧后额叶皮层、前前额叶皮层、楔前叶和扣带沟产生了连接的激活。女性的左右半球之间的连接也比男性更紧密。当前的研究结果表明，在认知神经科学研究中，不分性别进行汇总可能是不合理的。
