Perceptual constancy in babies: what they see and we don’t

We tend to assume that babies don’t have as good vision as adults. In fact, a newborn has very poor visual acuity, and it is during the first months of life that he is able to focus his eyes and discriminate colors. Even so, Infants are able to identify certain nuances that, to the eyes of an adult, are imperceptible. This is due to the so-called perceptual constancy.

This ability does not develop until approximately five or six months of age. And, although it may seem like a loss (because we stop grasping those subtleties), the truth is that it is a necessary process to understand the world. Without this perceptual constancy it would be very difficult for us to organize reality. and understand the stimuli that surround us. We tell you why below.

Babies perceive changes in images due to lighting, even when their sense of vision has not fully developed.

What do babies see and we don’t?

As we said, babies’ vision takes time to develop, and at first it is quite limited. At first his vision is blurry and unable to focus on distant objects. They do not perceive depth of field nor have they yet developed stereoscopic (or three-dimensional) vision. Furthermore, it is difficult for them to distinguish less saturated colors, and they cannot discriminate between different shades of the same color.

Now, despite these limitations inherent to their still immature development, there is an advantage that they have. And it is that They are able to perceive nuances and differences in images due to lighting that we adults fail to appreciate. This is what a study carried out in 2015 found. It measured the response of several babies to three images (A, B and C) that were similar but with certain differences.

A and B show the same object, but they differ in the intensity of the pixels between them. B and C, on the other hand, are more similar in that aspect, but differ in the fact that they have a glossy and matte surface respectively.

The results showed that babies less than five months They are very capable of perceiving those nuances or variations in terms of pixel intensity (something that is imperceptible for adults).

However, they do not grasp the difference in surface (glossy or matte) until they are seven or eight months old. In this way, this initial perceptual advantage is lost, and between 5 and 7 months they are at their lowest point of perception, since they have not yet acquired the perceptual constancy typical of mature vision.

Perceptual constancy and its importance

And why does the above happen? What are the reasons for these changes in visual capacity that occur during the first months of life? The answer lies in the development of perceptual constancy. This term refers to the ability we have to perceive an object or quality as constanteven if we don’t always feel it the same way.

For example, we can recognize that a chair is a chair, or that our brother is our brother, even if the lighting conditions change. We can also distinguish an instrument even when we hear it at different volumes or played by different players. Or, for example, we continue to perceive that an object is still, even when we see it differently when we approach it.

Perceptual constancy is, in short, the ability to abstract ourselves from those elements that vary to recognize a constancy in the object or quality. Somehow, we create the illusion that there are no differences, and we really stop noticing them. But this has a function.

It’s really not a failure or a loss of skill that we should regret. Perceptual constancy has been fundamental during evolution and continues to help us understand the environment and function in it. Without it, we would stop recognizing an object (or a person) simply because we look at it from another perspective or because it is more or less illuminated.

Perceptual constancy is a capacity that is not innate, but is learned.

In what other situations is perceptual constancy relevant?

In short, perceptual constancy is what allows us to adjust to the stimulus and be able to discriminate the aspects that interest us most, ignoring those that are irrelevant. However, although it is a fundamental and necessary capacity, There is a part of reality that we lose forever by learning to discriminate.

For example, it has been seen that babies (who have not yet developed this ability) are able to identify and differentiate between various monkey faces (something that would be really difficult for an adult). But also, It is a phenomenon also related to the acquisition of speech.

And it is true that hearing also develops and refines as the child grows, and that in a baby it still has limitations. However, before acquiring perceptual constancy, Babies are much more sensitive to acoustic variations and they easily distinguish pronunciations, accents and nuances. For this reason, an infant has the ability to learn any language very easily if he or she is exposed to it from the beginning of his or her life. On the contrary, when we learn to discriminate, it is much more difficult for us to capture those subtleties of each language and reproduce them.

In short, with all of the above we know that our perception is not a faithful reflection of reality, and that our senses “deceive” us in order to help us make sense of our environment and be able to respond to it.

Perceptual constancy is not innate, but is developed and learned; However, it is probably a change that is programmed to happen because of how useful and necessary it is for us as a species.

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