Introduction
Newborns come into the world, fully possessing the ability to perceive the environmental signals and react to it. Babies can see and hear, smell and touch, feel pressure and pain. They can choose what to look at. They learn, although their abilities are limited. The first 2 years of development are characterized by astonishing speed and depth in comparison with changes in any other 2-year period of human life. There is an amazing transition from a deep ignorance about the surrounding objects, sounds and smells to gaining basic knowledge about objects and people, language and daily activities occur during this period.
Sensory development is associated with a sensory perception of the world, in other words, the perception of the surrounding objects through the senses: vision, hearing, touch, smell. Sensory development is linked to recognition of shapes, sizes, colors, odors of different objects. To understand what a thing is, the child necessarily has to touch it, to see it, etc.
In this paper we will discuss the development of visual, audial and other sensory systems and perception of newborns and infants.
Sensations, translating external stimuli into neural impulses, are already highly developed in infancy. The perception which is associated with interpretations of the information received from the senses, on the other hand, is very limited and selective at birth. It is a cognitive process that analyzes sensory information and gives it meaning. It is developing rapidly in the first 6 months of life, followed by a slower fine tuning of perceptual processes in a few years(Craig, 1996).
During the first 4-6 months infant, the visual sensory system rapidly develops. They explore the world visually even before they learn to crawl and grab objects by hands. From the birth, children look at the surrounding objects selectively. They prefer to stare at new and relatively complex "picture" of objects and faces. However, during the first year changes occur regarding what attracts an attention of a child. In the first months of a life a baby looks at only the contours of a face; to the 2 months, they begin to fix their gaze on a person`s eyes(Craig, 1996).
Experiments of Carpenters have shown that 2-week-old babies prefer a mother's face. Scientist demonstrated to each child a picture with an image of a mother and picture with image of another woman. Two-weeks-old babies have preferred to look at the familiar face (Craig, 1996).
At the 4 months of age, babies prefer more often and longer to look at correct images of humans` faces than at distorted one. At 5 months, infants look at the mouth of a speaker, and at 7 months of age children look at faces as a whole and can distinguish between different types of facial expressions, for example, distinguish "happiness" from "fear» (Nelson, de Haan, 1996).
We can say with certainty that infants from the first days of their lives can hear. They wince when to hear loud sounds. When infants hear sounds such as lullabies, they calm down. In response to squeaks and whistles, they become excited. Infants are able to localize the source of sounds. Already in the first days of life, they turn their heads to the sound or voice. Later, they guided by the sound signals become able to determine the object's position in the darkness (LaGasse, Van Vorst, Brunner & Zucker, 1999).
As newborns, older infants are attentive to voices of the people. By 4 months, they smile in response to a mother's voice more often than in response to another woman's voice. By 6 months they exhibit anxiety when they hear the voice of the mother but cannot see her. Now the mother is no longer able to calm the child, just talking to him, being in another room.
The organs of taste and smell fully function since a birth. Infants distinguish sweet, salty, bitter and sour tastes. They mimic reactions different for each of these groups of taste. They react negatively to strong odors, and positively to pleasant flavors such as odors emanating from their mothers. The six-day child is able to distinguish the smell of his/her mother and the smell of another woman. Furthermore, an infant prefers the familiar smell (Craig, 1996).
In one classic study, infants sucked one of the two pacifiers: knobby or smooth. When the pacifier was taken away from babies` mouths and then showed both babies, children looked longer at those pacifiers they had held in their mouths before. In another experiment, 4-month-old infants watched two movies with similar sound. Sound corresponded to only one of two movies. Infants preferred to watch that film, which was combined with the appropriate sound. The result of two described experiments indicated the presence of visual-auditory integration. It means that visual, audial and other sensory system develop together and not separately (Craig, 1996).
Conclusions
The sensory system of children develops intensively in first years of life. An infant in first months of life can recognize familiar and unfamiliar faces, correct and distorted contours of objects, etc. A baby does not only distinguish different sounds, images, tastes but also react to it by positive or negative emotions. A child demonstrates a happiness and pleasure when to notice mother`s face or hear her familiar voice, but shows concern when to see strangers, etc.
Besides that, visual, audial, tactile and other senses develop intensively in infancy, these senses develop not isolated from each other. Different senses develop in integration with each other as results of the different study demonstrated.
The fact that sensory system and perceptions of infants develop intensively and rapidly means that parents and other caregivers of a child have to provide an appropriate amount of visual, audial and other types of sensory stimulation for a child. Sensory development can influence a cognitive development of a child on the further stages of development.
References
Craig, G. J. (1996). Human development . Prentice-Hall, Inc.
LaGasse, L. L., VanVorst, R. F., Brunner, S. M., & Zucker, M. S. (1999). Infants’ understanding of auditory events. Infant and Child Development, 8(2), 85-100.
Nelson, С. А. & De Haan, M. (1996). Neural correlates of infants' visual responsiveness to facial expression of emotion. Developmental Psychobiology, 29, 577-595.
