Graduate School of Biomedical Sciences, Nagasaki University, 1-12-4 Sakamoto-cho, Nagasaki City, Nagasaki 852-8523, Japan.
Neuropsychologia. 2012 Jun;50(7):1297-307. doi: 10.1016/j.neuropsychologia.2012.02.013. Epub 2012 Mar 1.
Crying by an infant signals an urgent desire for care and protection. Because of the special relationship between a mother and her infant and the signal value of her crying, it is plausible to suggest that the maternal brain efficiently processes crying by infants. In the present study, we examined this hypothesis by measuring event-related potentials in mothers while they observed crying or smiling by their own or unfamiliar infants embedded within a train of neutral expressions. We found that the amplitude of the face-specific N170 component was enlarged for crying regardless of familiarity. The P300 component, which reflects a later cognitive evaluation stage of stimulus processing, was decomposed into functionally distinct components by temporal principal component analysis. The amplitude of the third temporal factor, which corresponds to the earliest portion of the P300, was larger when a mother observed her own infant crying than for the other conditions. Moreover, onset latency of P300 was shortest when mothers observed their own infant crying. These results indicate that mothers process their own infant's crying more efficiently than smiling by their own infant or crying by an unfamiliar infant.
婴儿的哭泣传达了对照顾和保护的迫切需求。由于母亲和婴儿之间的特殊关系以及她哭泣的信号价值，因此可以合理地假设母亲的大脑能够有效地处理婴儿的哭泣。在本研究中，我们通过测量母亲在观察自己或陌生婴儿的哭泣或微笑时的事件相关电位，同时观察他们的中性表情序列，来检验这一假设。我们发现，无论熟悉程度如何，哭泣时的面孔特异性 N170 成分的振幅都增大了。P300 成分反映了刺激处理的后期认知评估阶段，通过时间主成分分析将其分解为功能不同的成分。当母亲观察自己的婴儿哭泣时，与其他条件相比，对应 P300 最早部分的第三个时间因素的振幅更大。此外，当母亲观察自己的婴儿哭泣时，P300 的起始潜伏期最短。这些结果表明，母亲处理自己婴儿的哭泣比处理自己婴儿的微笑或陌生婴儿的哭泣更有效。
