婴儿面孔和注视方向加工的认知神经机制

doi:10.3724/SP.J.1042.2024.01670

摘要/Abstract

摘要：

面孔和注视方向是人际交往中重要的社会线索。探讨婴儿特别是新生儿对面孔和注视方向的加工, 有助于深入理解人类社交能力的起源及发展过程。回顾前人研究我们发现: 0~28日龄的新生儿普遍表现出对人类面孔和直视的偏好, 3月龄的婴儿开始表现出对他人目光的注视追随能力。脑观测研究发现3月龄以上的婴儿对面孔和注视加工具有与成人类似的脑神经表现。未来研究可以采用多种脑观测(特别是新型脑磁图)技术进一步考察新生儿的面孔偏好、直视偏好以及婴儿的注视追随现象, 揭示婴儿对人类面孔和眼睛注视加工先天优势的神经基础及其受后天经验影响的认知机制。

关键词: 面孔, 注视方向, 新生儿, 婴儿, 社会交往

Abstract:

Faces and gaze direction are crucial social cues in interpersonal interactions. Investigating how infants, particularly newborns, process these cues enhances our understanding of the origins and development of human social abilities. A review of existing literature shows that neonates (0~28 days old) generally prefer human faces and direct gaze, while infants around 3 months old begin to follow gaze direction. Brain imaging studies reveal that infants older than 3 months exhibit neural responses to faces and gaze processing similar to those of adults.

Newborns demonstrate a preference for human faces from birth. They exhibit this bias regardless of whether presented with real faces, sketched faces, or face-like patterns with just three dots and a contour. Event-related potential (ERP) studies indicate that infants aged 3 to 6 months show brain responses similar to adults. Specifically, infants exhibit a stronger amplitude and shorter latency of N290 towards faces compared to objects, and a larger P400 amplitude when viewing familiar faces, with increased responses to inverted faces compared to upright faces and front faces compared to side faces. These infant ERP components resemble the adult face-specific N170 component. Functional magnetic resonance imaging (fMRI) studies show that at 5 months of age, infants display stronger activation in the fusiform gyrus, occipital cortex, superior temporal sulcus, and medial prefrontal cortex when viewing faces compared to natural scenes. Moreover, 5-month-old infants exhibit a face-selective region in the fusiform gyrus that is functionally and anatomically similar to that in adults. Furthermore, infant face processing shows a right hemisphere dominance (or left visual field bias) similar to that seen in adults.

Newborns also show a preference for direct gaze, looking longer at faces with direct eye gaze compared to faces with averted gaze. They demonstrate a familiarity effect (longer gaze durations during face recognition tasks for familiar faces compared to unfamiliar ones) only for faces with direct gaze. Additionally, infants aged three months and older display gaze-following behavior, with faster and more accurate saccades towards targets in the direction of others' gaze. Gaze following develops gradually from 3 to 12 months, with 6 months being a critical period for development. ERP studies reveal that direct gaze faces elicit a stronger N290 amplitude in 4-month-old infants compared to averted gaze faces, with direct gaze also triggering brain activity resembling that of a smile: a notable increase in brain electrical power observed in bilateral posterior temporal regions and the left frontal region. In a gaze-following study, congruent targets evoked weaker positive slow wave (PSW) amplitudes in 4-month-old infants compared to incongruent targets, a component reflecting familiarity with the stimulus. Additionally, functional near-infrared spectroscopy (fNIRS) studies found that 5-month-old infants showed significant activation of the left dorsolateral prefrontal lobe when performing the "gaze cue-target" task, whereas 7- to 12-month-old infants showed activation of the right dorsolateral prefrontal lobe, reflecting the developmental shift from exogenous to endogenous processing of gaze.

Cognitive neuroscience theories on newborns' facial preference include Johnson's two-process model and Turati's "non-specificity" theory. Johnson's model suggests faces are distinct stimuli, indicating an innate human ability to recognize faces. Turati's theory argues that newborns' facial preference stems from a preference for certain non-specific visual structures, such as the "top-heavy" configuration (more elements in the upper part than the lower part) and "inner-outer match" (alignment of internal geometric shapes with external contours, such as both being inverted triangles). Both theories acknowledge newborns' innate preference for specific visual stimuli, differing on whether faces are inherently special stimuli. The cognitive neural theory on infants' processing of gaze direction, proposed by Johnson's research group, includes the fast-track modulator model. This model posits that gaze direction information is processed through two pathways: a slow cortical pathway involving regions such as the superior temporal sulcus and fusiform gyrus, and a fast sub-cortical pathway involving regions like the superior colliculus and amygdala. The sub-cortical fast pathway is fully functional at birth, enabling newborns to quickly identify direct gaze cues and gradually activating broader cortical pathways during development, allowing for the processing of more complex gaze information.

In summary, research on infant face perception and gaze direction indicates that: 1) Newborns prefer faces; 2) Newborns prefer direct gaze; 3) Infants engage in gaze following, enhanced by prior direct eye contact experiences; 4) Infants' neural responses and brain networks for processing faces and gaze resemble those of adults. Prior studies have focused on whether facial and gaze are distinct stimuli for newborns, providing compelling exclusive and neuroimaging evidence. Future research should consider isolating the physical properties of faces and gazes more completely. Regarding experimental techniques, magnetoencephalography (MEG) is a promising technology, as its multi-channel high-density capabilities can resolve neural responses in very small subcortical nuclei.

Key words: face, gaze direction, newborn, infant, social interaction

中图分类号:

B844

郭桐阳, 莫李澄, 张丹丹. (2024). 婴儿面孔和注视方向加工的认知神经机制. 心理科学进展 , 32(10), 1670-1679.

GUO Tongyang, MO Licheng, ZHANG Dandan. (2024). Neural mechanisms of face and gaze processing in infants. Advances in Psychological Science, 32(10), 1670-1679.

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