Dissociating maternal responses to sad and happy facial expressions of their own child: An fMRI study

BackgroundMaternal sensitive behavior depends on recognizing one’s own child’s affective states. The present study investigated distinct and overlapping neural responses of mothers to sad and happy facial expressions of their own child (in comparison to facial expressions of an unfamiliar child).MethodsWe used functional MRI to measure dissociable and overlapping activation patterns in 27 healthy mothers in response to happy, neutral and sad facial expressions of their own school-aged child and a gender- and age-matched unfamiliar child. To investigate differential activation to sad compared to happy faces of one’s own child, we used interaction contrasts. During the scan, mothers had to indicate the affect of the presented face. After scanning, they were asked to rate the perceived emotional arousal and valence levels for each face using a 7-point Likert-scale (adapted SAM version).ResultsWhile viewing their own child’s sad faces, mothers showed activation in the amygdala and anterior cingulate cortex whereas happy facial expressions of the own child elicited activation in the hippocampus. Conjoint activation in response to one’s own child happy and sad expressions was found in the insula and the superior temporal gyrus.ConclusionsMaternal brain activations differed depending on the child’s affective state. Sad faces of the own child activated areas commonly associated with a threat detection network, whereas happy faces activated reward related brain areas. Overlapping activation was found in empathy related networks. These distinct neural activation patterns might facilitate sensitive maternal behavior.

背景 母亲敏感行为依赖于对自身孩子情感状态的识别。本研究探究了母亲在观看自身孩子（相较于陌生孩子）的悲伤与快乐面部表情时，所产生的独特且重叠的神经响应。
方法 本研究采用功能磁共振成像（functional MRI, fMRI），对27名健康母亲进行扫描，以捕获其在观看自身学龄孩子与性别、年龄匹配的陌生孩子的快乐、中性及悲伤面部表情时，可分离且重叠的激活模式。为探究母亲对自身孩子悲伤与快乐面部表情的差异化激活，我们采用交互对比分析。扫描过程中，母亲需对所呈现面部的情绪类型做出判断。扫描结束后，要求她们使用7点李克特量表（改编版自我评估模拟人（Self-Assessment Manikin, SAM））对每张面孔的感知情绪唤醒度与效价水平进行评分。
结果 当观看自身孩子的悲伤面孔时，母亲的杏仁核与前扣带回皮层出现激活；而自身孩子的快乐面孔则会引发海马体激活。母亲对自身孩子快乐与悲伤表情的共同激活脑区包括脑岛与颞上回。
结论 母亲的脑激活模式会随孩子的情感状态发生变化。自身孩子的悲伤面孔会激活通常与威胁检测网络相关的脑区，而快乐面孔则激活奖赏相关脑区。重叠激活则出现在共情相关网络中。这些独特的神经激活模式或可促进敏感的母亲行为。