37Cognitive DevelopmentUNIT 4 PERCEPTUAL DEVELOPMENT Structure
4.0 Introduction
4.1 Objectives
4.2 Aspects of Perceptual Developments 4.3 Critical Periods
4.3.1 Language Acquisition
4.3.2 Second Language Acquisition
4.4 Sensorimotor Activities
4.5 Sensory Acuity
4.5.1 Visual Acuity
4.6 Sensory Deprivation
4.7 Theories of Perceptual Development
4.8 Let Us Sum Up
4.9 Unit End Questions
4.10 Answers of Self Assessment Questions
4.11 Suggested Readings
4.0 INTRODUCTION
Perceptual development provides the basis for analysing and interpreting the
happenings in our external environment. Stimulation from the environment evoke
sensory experiences which promote growth and development of brain. For
example researches reveal that infants/toddlers with hearing loss receive limited
or distorted auditory input, consequently, they may experience delays in speech
and language development. Infants and children acquire knowledge of the world around them and its
operations through the sensations they receive from sensory stimuli. Development
of infants or toddlers to a large extent is determined by access to sensory
information in the environment. Perceptual development occurs as infants explore,
manipulate and identify different features in the environment, discovering
properties of and relationships between features. In fact, development of language
in children is the result of these sensory experiences that contribute to cognitive
growth and development.
For infants who are developing typically, the brain circuits and neural pathways
that form during the first year allow in the child to anticipate of mother’s entry
into a room upon hearing her voice or footsteps approaching while awakening
from a nap. Infants’ brains release endorphins during the experience of nurturing
skin to skin touch thus soothing anxiety when tired or stressed. Every time babies
experience new stimuli, their brains are fine-tuned to quickly interpret and process
similar experiences.
During the first three months of life, infants’ brains respond to the world of
sensation with greater electrical activity in areas of the brain responsible for
coding stimuli of sights, sounds, and touches. As perceptual development proceeds 38Biological Basis of
Behaviourinfants learn to associate stimuli with particular activities and anticipate events
(Raymond, 2000). For example, babies learn that father’s entry into the home
suggests that he can anticipate touches and hugs. Such experiences provide the
foundation for interpreting and making sense of the world. For infants and toddlers
who are deaf/hard of hearing, the extent of hearing loss and/or amplification
determines whether they rely primarily on hearing or vision, or combined input
from both modalities to interpret their environment and gain understanding in
the world around them.
4.1 OBJECTIVES
After completing study of this unit, you will be able to :
Define in your own words perceptual development;
Describe different aspects of perceptual development;
Understand the meaning and importance of critical period;
Identify the sensorimotor activities and their importance?
Define sensory acuity and how it develops;
Explain behavioural implication of sensory deprivation; and
Elucidate the theory of perceptual development.
4.2 ASPECTS OF PERCEPTUAL DEVELOPMENTS Touch
Touch is the very basis of interaction between parents and the child. Touching
promotes early physical growth and also plays vital role in emotional development.
Therefore sensitivity to touch is present at the time of birth. Newborn babies
react to touch particularly on palm, around mouth and in the soles of feet.
Infants are sensitive to sensation of pain however it has been found when sugar
nipples are inserted in mouth discomfort and crying are quickly reduced in the
young babies. When touch produces pleasure instead of pain it increases child’s
responsiveness to the environment. For example, you might have noticed that
when an infant is given soft soothing caresses he smiles and pays attention to
caregiver. Infants explore and investigate the world around them. They run their
hand on objects. When they develop the capability of reaching out to things,
babies first place any object into their mouth and then have a good look at the
object. This kind of exploration reaches its peak during the middle of first year
and declines afterwards as babies make more use of hands to explore and
investigate objects from different angles. For example infants of one year or
more would turn an object around, feel its surface, rub the surface to see what
happens and then again pick it up to view it with both hands.
Taste and Smell
Reactions to taste and smell are crucial for survival. Infants are innately
programmed for their taste preferences. Newborns are able to distinguish several
basic tastes in the manner of an adult. For example, they respond to sweetness
by relaxing their facial muscles, and when the taste is sour they react by distorting
their lips and so on. Taste for salty objects is not present at birth time. But by the
4.0 Introduction
4.1 Objectives
4.2 Aspects of Perceptual Developments 4.3 Critical Periods
4.3.1 Language Acquisition
4.3.2 Second Language Acquisition
4.4 Sensorimotor Activities
4.5 Sensory Acuity
4.5.1 Visual Acuity
4.6 Sensory Deprivation
4.7 Theories of Perceptual Development
4.8 Let Us Sum Up
4.9 Unit End Questions
4.10 Answers of Self Assessment Questions
4.11 Suggested Readings
4.0 INTRODUCTION
Perceptual development provides the basis for analysing and interpreting the
happenings in our external environment. Stimulation from the environment evoke
sensory experiences which promote growth and development of brain. For
example researches reveal that infants/toddlers with hearing loss receive limited
or distorted auditory input, consequently, they may experience delays in speech
and language development. Infants and children acquire knowledge of the world around them and its
operations through the sensations they receive from sensory stimuli. Development
of infants or toddlers to a large extent is determined by access to sensory
information in the environment. Perceptual development occurs as infants explore,
manipulate and identify different features in the environment, discovering
properties of and relationships between features. In fact, development of language
in children is the result of these sensory experiences that contribute to cognitive
growth and development.
For infants who are developing typically, the brain circuits and neural pathways
that form during the first year allow in the child to anticipate of mother’s entry
into a room upon hearing her voice or footsteps approaching while awakening
from a nap. Infants’ brains release endorphins during the experience of nurturing
skin to skin touch thus soothing anxiety when tired or stressed. Every time babies
experience new stimuli, their brains are fine-tuned to quickly interpret and process
similar experiences.
During the first three months of life, infants’ brains respond to the world of
sensation with greater electrical activity in areas of the brain responsible for
coding stimuli of sights, sounds, and touches. As perceptual development proceeds 38Biological Basis of
Behaviourinfants learn to associate stimuli with particular activities and anticipate events
(Raymond, 2000). For example, babies learn that father’s entry into the home
suggests that he can anticipate touches and hugs. Such experiences provide the
foundation for interpreting and making sense of the world. For infants and toddlers
who are deaf/hard of hearing, the extent of hearing loss and/or amplification
determines whether they rely primarily on hearing or vision, or combined input
from both modalities to interpret their environment and gain understanding in
the world around them.
4.1 OBJECTIVES
After completing study of this unit, you will be able to :
Define in your own words perceptual development;
Describe different aspects of perceptual development;
Understand the meaning and importance of critical period;
Identify the sensorimotor activities and their importance?
Define sensory acuity and how it develops;
Explain behavioural implication of sensory deprivation; and
Elucidate the theory of perceptual development.
4.2 ASPECTS OF PERCEPTUAL DEVELOPMENTS Touch
Touch is the very basis of interaction between parents and the child. Touching
promotes early physical growth and also plays vital role in emotional development.
Therefore sensitivity to touch is present at the time of birth. Newborn babies
react to touch particularly on palm, around mouth and in the soles of feet.
Infants are sensitive to sensation of pain however it has been found when sugar
nipples are inserted in mouth discomfort and crying are quickly reduced in the
young babies. When touch produces pleasure instead of pain it increases child’s
responsiveness to the environment. For example, you might have noticed that
when an infant is given soft soothing caresses he smiles and pays attention to
caregiver. Infants explore and investigate the world around them. They run their
hand on objects. When they develop the capability of reaching out to things,
babies first place any object into their mouth and then have a good look at the
object. This kind of exploration reaches its peak during the middle of first year
and declines afterwards as babies make more use of hands to explore and
investigate objects from different angles. For example infants of one year or
more would turn an object around, feel its surface, rub the surface to see what
happens and then again pick it up to view it with both hands.
Taste and Smell
Reactions to taste and smell are crucial for survival. Infants are innately
programmed for their taste preferences. Newborns are able to distinguish several
basic tastes in the manner of an adult. For example, they respond to sweetness
by relaxing their facial muscles, and when the taste is sour they react by distorting
their lips and so on. Taste for salty objects is not present at birth time. But by the
