Paukner Annika, Pedersen Eric J, Simpson Elizabeth A
Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Poolesville, Maryland, United States of America.
Department of Psychology, University of Miami, Coral Gables, Florida, United States of America.
PLoS One. 2017 Jun 15;12(6):e0178864. doi: 10.1371/journal.pone.0178864. eCollection 2017.
Neonatal imitation is the matching of (often facial) gestures by newborn infants. Some studies suggest that performance of facial gestures is due to general arousal, which may produce false positives on neonatal imitation assessments. Here we examine whether arousal is linked to facial gesturing in newborn infant rhesus macaques (Macaca mulatta). We tested 163 infants in a neonatal imitation paradigm in their first postnatal week and analyzed their lipsmacking gestures (a rapid opening and closing of the mouth), tongue protrusion gestures, and yawn responses (a measure of arousal). Arousal increased during dynamic stimulus presentation compared to the static baseline across all conditions, and arousal was higher in the facial gestures conditions than the nonsocial control condition. However, even after controlling for arousal, we found a condition-specific increase in facial gestures in infants who matched lipsmacking and tongue protrusion gestures. Thus, we found no support for the arousal hypothesis. Consistent with reports in human newborns, imitators' propensity to match facial gestures is based on abilities that go beyond mere arousal. We discuss optimal testing conditions to minimize potentially confounding effects of arousal on measurements of neonatal imitation.
新生儿模仿是指新生儿对（通常是面部的）手势进行匹配。一些研究表明，面部手势的表现是由于一般性唤醒，这可能会在新生儿模仿评估中产生假阳性结果。在这里，我们研究了唤醒是否与新生恒河猴（猕猴）的面部手势有关。我们在新生儿出生后的第一周，以新生儿模仿范式对163只婴儿进行了测试，并分析了他们的咂嘴手势（嘴巴快速开合）、伸舌手势和哈欠反应（一种唤醒指标）。与所有条件下的静态基线相比，在动态刺激呈现过程中唤醒水平增加，并且面部手势条件下的唤醒水平高于非社交控制条件。然而，即使在控制了唤醒因素之后，我们发现，在匹配咂嘴和伸舌手势的婴儿中，面部手势出现了特定条件下的增加。因此，我们没有找到支持唤醒假说的证据。与人类新生儿的报告一致，模仿者对面部手势进行匹配的倾向基于超越单纯唤醒的能力。我们讨论了优化测试条件，以尽量减少唤醒对新生儿模仿测量可能产生的混淆效应。
