Department of Functioning and Disability, Institute for Developmental Research, Aichi Developmental Disability Center, Japan.
Department of Psychology, Japan Women's University, Japan.
Neuroimage. 2021 Dec 1;244:118598. doi: 10.1016/j.neuroimage.2021.118598. Epub 2021 Sep 27.
Previous functional neuroimaging studies imply a crucial role of the superior temporal regions (e.g., superior temporal sulcus: STS) for processing of dynamic faces and bodies. However, little is known about the cortical processing of moving faces and bodies in infancy. The current study used functional near-infrared spectroscopy (fNIRS) to directly compare cortical hemodynamic responses to dynamic faces (videos of approaching people with blurred bodies) and dynamic bodies (videos of approaching people with blurred faces) in infants' brain. We also examined the body-inversion effect in 5- to 8-month-old infants using hemodynamic responses as a measure. We found significant brain activity for the dynamic faces and bodies in the superior area of bilateral temporal cortices in both 5- to 6-month-old and 7- to 8-month-old infants. The hemodynamic responses to dynamic faces occurred across a broader area of cortex in 7- to 8-month-olds than in 5- to 6-month-olds, but we did not find a developmental change for dynamic bodies. There was no significant activation when the stimuli were presented upside down, indicating that these activation patterns did not result from the low-level visual properties of dynamic faces and bodies. Additionally, we found that the superior temporal regions showed a body inversion effect in infants aged over 5 months: the upright dynamic body stimuli induced stronger activation compared to the inverted stimuli. The most important contribution of the present study is that we identified cortical areas responsive to dynamic bodies and faces in two groups of infants (5-6-months and 7-8-months of age) and we found different developmental trends for the processing of bodies and faces.
先前的功能神经影像学研究表明，颞上区域（例如，颞上沟：STS）在处理动态面部和身体方面起着至关重要的作用。然而，对于婴儿期移动面部和身体的皮质处理知之甚少。本研究使用功能近红外光谱（fNIRS）直接比较了婴儿大脑中对动态面部（带有模糊身体的人接近的视频）和动态身体（带有模糊面部的人接近的视频）的皮质血流动力学反应。我们还使用血流动力学反应作为测量指标，检查了 5 至 8 个月大婴儿的身体反转效应。我们发现，在 5 至 6 个月和 7 至 8 个月的婴儿的双侧颞叶皮质的上区，都有显著的大脑活动。7 至 8 个月大的婴儿的血流动力学反应比 5 至 6 个月大的婴儿的血流动力学反应跨越更广泛的皮质区域，但我们没有发现动态身体的发育变化。当刺激物倒置时，没有显著的激活，表明这些激活模式不是由于动态面部和身体的低水平视觉特性引起的。此外，我们发现，颞上区域在 5 个月以上的婴儿中表现出身体反转效应：与倒置刺激相比，直立的动态身体刺激引起更强的激活。本研究的最重要贡献是，我们在两组婴儿（5-6 个月和 7-8 个月）中确定了对动态身体和面部有反应的皮质区域，并且我们发现了身体和面部处理的不同发展趋势。
