婴儿的发展可以衡量的方式，他们遵循的互动伙伴的视线方向的结果[ 24 ]。凝视行为被称为一个人的注意力的焦点，从而参考源[ 25 ]。如果没有有效沟通的方法，并解释了更高的感知概念，在婴儿中，可以使用参考源是婴儿感知的。在凝视运动的变化的解释，涉及到孩子是否在参照的条款构思的任务-例如，是专门针对对象的感知方面的凝视。因此，虽然适当的反应后，可能会出现，婴儿实际上没有任何感性的证据，为什么他们这样做[ 26 ]。 视觉感知显着发展2至6个月[ 27 ]。儿童必须发展感知的一个重要因素是感觉信息与实际物体之间存在着不一致的地方。这种知觉恒常性包括当看着一桌角出现斜或急性的，也可以是直角[ 28 ]。因此，世界是由所看到的，而不是直接观察。这种附加信息的使用是随着年龄的增长而发展的。然而，应该指出的是，仅仅因为一个行为在出生时是不可见的，但这并不意味着它不存在，因为它可能只是还没有成熟到可以测量[ 29 ]和缺乏沟通技巧可以使婴儿对他们的感知程度建议。这意味着，许多与婴儿感知有关的证据都是基于这种认知的推论。实验者必须根据他们认为可能的结果推断出感知的程度，以及婴儿做出反应的结果
Infant development can be gauged as a result of the way in which they follow the gaze direction of interactive partners. Gaze behaviour is referred to as an indicator of a person’s focus of attention, thus the source of reference. Without the means to communicate effectively and explain the higher concept of perception, in an infant it may be possible to use the source of reference to be what the infant perceives. Explanations for the change in gaze movement are suggested to relate to whether the child is conceiving the task in referential terms – e.g. is specifically targeting the gaze in terms of the object perceived. So, whilst the appropriate response of gaze following may occur, the infant does not in fact have any perceptual evidence for why they do this.
Visual perception develops markedly between 2 and 6 months. One important element of perception that a child must develop is where there are inconsistencies between the sensory information presented and the actual objects. Such perceptual constancies include when looking at a table the angles appear to be oblique or acute, yet can be known to be right-angles. Thus the world is constructed from what is seen, rather than observed directly. This use of additional information is something that develops with age. However it should be noted that, just because a behaviour is not observable at birth, it doesn’t mean that it doesn’t exist, as it may simply have not yet matured enough to be measured and the lack of communication skills may preclude the infant from advising on the extent of their perception. This means that much of the evidence relating to infant perception is based on an inference of that perception. The experimenter has to infer the degree of perception based on what they think is likely and as a result of what the infant does to react