When talking about information processing in babies, a good deal of time is usually devoted to vision and how babies see. This is because during the first months of life, the mechanisms for processing visual information are developed and refined.
A Max Planck Institute survey conducted in thirteen countries found that the majority of verbalizations in reference to the five senses corresponded to vision. This is significant, since human beings are born with numerous deficits that influence vision in the first months. Let us see what the visual capacities of the newborn baby are and what changes take place in vision in the first months.
Visual capacities of the newborn baby
It is necessary to take into account that, in the case of newborns, none of the neural systems involved in human vision are fully developed. This includes very important areas of the eyes, such as the retina and the geniculate nucleus, for example.
Babies do not see pastel shades
The fovea, related to colour vision, is very poorly developed, although it undergoes a great deal of change during the first few months. This means that the baby has very little sensitivity to contrast, which is acquired during the first months of life. Therefore, at birth, babies can only distinguish red, white and black. At two months, they are able to make most of the distinctions and only at four or five months do they obtain the vision of all colours.
From this idea, if a baby is offered several toy options (red, pink, beige or green), they will always prefer the red one. They will always want the toys with the most contrast. If this baby were five months old, he might choose the green toy, since at this age he is already beginning to differentiate this colour.
The tradition of pastel and light colours for newborn babies is impractical with respect to what they can perceive; they will not see these colours at first. Therefore, red, white and black toys with contrasts and vivid colours are recommended.
Eye muscles. Why do babies see double vision?
The straight muscles – which allow the eyeball to move – and the ciliary muscles – which support the lens – are very tight and rigid when a baby is born. These muscles influence the baby’s ability to follow and saccadic movements. As these muscles relax, vision in the first few months improves. This usually happens between two and three months of age.
Due to the rigidity of the ciliary muscles, the lens also does not function fully. The lens is responsible for accommodation and so for some months babies have difficulty focusing on what is near and what is far away. In addition, they have double vision because these muscles are not very flexible, i.e. they do not have binocular vision. They see two visual fields that do not overlap.
Do babies see and perceive details?
Visual acuity is the ability to see details or spatial frequency. With regard to vision in the first months of life, newborns see only 30% of the details that an adult is capable of perceiving. This begins to improve only at four months, until the level of vision an adult has is reached by the age of one year. For babies to be able to see detail, the position of the object must not be too far away or too close. The best level of vision for babies is two metres.
How is it possible for one-month-old babies to recognise their parents if their visual acuity is far below that of six-month-olds or one-year-olds?
This can be answered thanks to the baby’s range of options. Human beings are multimodal, i.e. they are guided by more than one sensory pathway. The best distance merges with movement information, smells, etc., leading to their recognition through sensory integration.
What are babies’ preferences?
Babies prefer to look at what they are able to grasp. It is their limitations that lead them to prefer some things over others. When babies are born, they usually pay attention to edges, contours or angles. This is because these are the parts of objects that offer a contrast that he can grasp. So at first, the baby is not able to see a face. It won’t even see the features of the person’s face. It will prefer the outline of that face. At one month, it begins to perceive the eyes, the mouth or the chin.
At first, the baby’s preference criterion is that it be visible, determined by the object itself. His preference will depend on the intrinsic and spare properties of that object. During the second month, the preference criterion begins to be experienced. Babies see according to the meaning of the object. The cognitive system will develop and then it will be possible to determine whether a stimulus is new or interesting.
Understanding objects as separate entities from others
Another function that has not yet fully developed, and which influences vision in the early months, is the ability to separate surface, object and background. This allows us to understand the world as it is and also others. Before the age of five months, a baby is not able to differentiate surface and background objects. This means that if they look at a jug of juice and, from behind, a wall, they will think that both objects are the same.
From five months, they can differentiate if the objects are sufficiently separated. Movement helps to make this differentiation. If these objects are static, at least before five months, they will not be differentiated.
With regard to objects that share surfaces, until four months of age the baby will also not know that they are two different objects. It doesn’t matter if they have different colours. The principles of continuity, connected surfaces and common movement are relevant. Shapes, in general, say nothing.
Perception of faces. Do babies look at us?
During the first month, as we mentioned before, babies begin to perceive the content of people’s faces better. From the second month a lot of progress is made, and they manage to become experts at this. At two months they already have a high tracking pattern. Babies look at faces more than any other stimulus, and begin to show preferences for familiar faces.
At six months babies can already see and recognize a face despite variations in expression, even from the front or from the side. They can already categorize according to sex, differentiate emotional expressions and respond differently to attractive or unattractive faces.
Sight is perhaps the major protagonist in the development of perception in babies. The changes they experience during their first year of life are astonishing. Sight, among other things, is what allows babies to develop and get to know the world around them little by little.
