婴幼儿面孔注意偏向:先天倾向与发展轨迹——来自正常和孤独症婴幼儿的证据

Attention bias to faces in infants and toddlers:Inborn predispositions and developmental changes

正常发展(Typically developing,TD)婴儿的先天面孔注意倾向稳定地存在于不同发展阶段不同刺激情景中,且在生命第一年内呈现短暂下降后快速增强的发展趋势。TD婴幼儿的视觉注意在第4至6周之间发生由皮下控制向皮层控制的关键性转变之后,伴随面孔视觉经验的不断积累,逐渐形成的面孔特异性皮层网络对面孔的优先选择性反应逐渐增强。而孤独症谱系(Autism Spectrum Disorder,ASD)婴幼儿具备初始的面孔注意先天倾向,但在面孔皮层发育关键期内逐渐偏离正常轨道,在1岁左右表现出面孔注意障碍。该群体先天的感知注意损伤或社会动机缺失可能导致其在关键性转变期内的面孔视觉经验输入不足,进而阻碍面孔特异性皮层网络的正常发展。未来研究可考虑采用生物遗传学方法和近红外脑成像技术探索新生儿面孔注意先天倾向的起源,系统考察社会场景中感知觉特征和社会性特征对ASD高危婴儿面孔注意发展轨迹尤其是关键性转变期的影响作用。

Typically developing individuals not only show an inborn predisposition to pay attention to faces from birth,but also present a stable attention bias to faces in different developmental stages and situations.There remains a theoretical divergence on the underlying mechanism of this innate predisposition of facial attention between the sub-cortical face template and the proto-organization of the visual cortex.However,the neural basis of the postnatal development of this mechanism is generally considered to be the preferential selective response of the face-selective area that gradually forms with the accumulation of facial visual experiences.However,infants with autism spectrum disorder(ASD)may suffer from insufficient input of face visual experience due to impaired perception and attention or the lack of social motivation,which may hinder the formation of the face-selective area.Studies have confirmed that infants with ASD have an initial predisposition to pay attention to faces,but gradually deviate from the normal track during the critical period of facial cortex development,showing an obvious impairment of facial attention at the end of infancy.In future research,we should explore the origin of the congenital predisposition of facial attention in neonates by using genetic methods and near-infrared brain imaging technology,and systematically investigate the influence of perceptual and social characteristics on the development track of face attention in high-risk infants with ASD to identify the potential mechanism responsible for facial attention impairment.