Early development of top-down perceptual modulations in infancy

人类发展的主要目标之一是适应环境。这种适应过程早在婴儿期就表现在我们的感知能力上。在最初的几个月里，感知变得越来越专业化，以处理环境中最具代表性的信息。例如，虽然3个月大的婴儿可以辨别各种刺激，但到了9到12个月大时，他们只能辨别熟悉的刺激(例如，本种族的面孔和母语)，但失去了区分陌生的其他种族的面孔或非母语的讲话的能力。尽管这种基于经验的早期发育几十年来一直有报道，但将感觉经验转化为婴儿感知能力的机制还不太清楚。目前的项目不是将早期知觉发展视为被动接触特定类型的感觉输入的结果，而是专注于在生命的第一年积极利用经验塑造知觉的能力。这种能力被称为自上而下的知觉调节，学习到的知识可以被积极地用来调节相关的知觉系统，从而导致最佳的知觉结果。例如，在听到狗叫声后，我们的视觉系统将准备处理与狗有关的视觉信息，这会导致对狗的增强感知。目前的计划旨在调查自上而下的知觉调节如何支持新生儿和婴儿的早期知觉发展。自上而下的知觉调节将在大脑和婴儿的眼球运动模式中进行神经探测和行为探测。所提出的研究为早期知觉发展提供了新的理论进展。这一结果将揭示婴儿出生时自上而下感知调节的神经机制，这使得婴儿能够利用他们不断扩大的关于世界的知识来适应感知能力的变化。此外，这些发现将为建立以证据为基础的早期干预计划提供信息，这些计划针对发育迟缓的根本原因，如早产造成的发育迟缓。

One of the major goals of human development is to adapt to the environment. This adaptation process first manifests in our perceptual capacities as early as infancy. Over the first few months, perception becomes increasingly specialized to process the most representative information in the environment. For example, while 3-month-olds can discriminate a wide range of stimuli, by 9 to 12 months of age, they can only discriminate familiar stimuli (e.g., own-race faces and native speeches) but lose the ability to differentiate unfamiliar other-race faces or non-native speeches. Though such experience-based early development has been consistently reported over decades, the mechanisms that translate sensory experiences into infants' perceptual capacities are less clear. Instead of viewing early perceptual development as the result of passive exposure to particular types of sensory input, the current program focuses on the ability to actively utilize experiences to shape perception in the first year of life. This capacity is referred to as top-down perceptual modulation, where the learned knowledge can be actively used to modulate related perceptual systems, therefore leading to optimal perceptual outcomes. For example, after hearing a dog bark, our visual system will be prepared to process dog related visual information, which results in an augmented perception of dogs. The current program aims to investigate how top-down perceptual modulation, which will be probed neurally in the brain and behaviourally in infants' eye movement patterns, supports the early development of perception in neonates and infants. The proposed studies present a novel theoretical advance regarding early perceptual development. The results will reveal the neural mechanisms underlying the top-down perceptual modulation at birth, which allows infants to leverage their expanding knowledge about the world into adaptive changes in perceptual abilities. Moreover, the findings will inform the creation of evidence-based early intervention programs that target the root cause of developmental delay, such as those caused by premature birth.