Growth of Body and Brain
A child’s body grows most dramatically during the first year of life; growth proceeds at a rapid but diminishing rate during the next 2 years. Normal physical growth and motor development proceed according to the cephalocaudal and proximodistal principles. Breastfeeding offers many physiological and psychological benefits to the infant. However, the quality of the relationship between parents and baby is the most important element in promoting healthy psychological development. During the latter half of the first year, babies may begin to eat solid foods. Obesity in infancy does not necessarily predict obesity later in life. Much of the brain’s growth after birth consists of the formation of synapses, or connections between nerve cells. Due to the brain’s plasticity, especially during this critical period of growth, environmental experience can influence brain development positively or negatively.
Early Sensory Capacities
Sensory capacities, present from birth and even in the womb, develop rapidly in the first months of life. Very young infants show pronounced abilities to discriminate between stimuli. Touch seems to be the first sense to develop and is the most mature sensory system for the first several months. Newborns are sensitive to pain, smell, taste, and hearing begins to develop in the womb. A preference for sweet taste seems to be inborn and probably helps infants adapt to life outside the womb. Odor preferences develop with experience. Vision is the least well developed sense at birth. Peripheral vision, color perception, acuteness of focus, binocular vision, and the ability to follow a moving object with the eyes all develop within the first few months. Visual preference and auditory discrimination appear to be related to later cognitive functioning.
Reflex behaviours
Reflex behaviours are indications of neurological maturation. Primitive reflexes drop out during the first year as voluntary, cortical control develops.
Primitive reflexes are reflex actions originating in the central nervous system that are exhibited by normal infants but not neurologically intact adults, in response to particular stimuli. These reflexes disappear or are inhibited by the frontal lobes as a child moves through normal child development. (Rauch, 2006). These primitive reflexes are also called infantile, infant or newborn reflexes. Older children and adults with atypical neurology (for instance, people with cerebral palsy) may retain these reflexes and primitive reflexes may re-appear in adults due to certain neurological conditions including, but not limited to, dementia, traumatic lesions, and strokes (Schott and Rossor, 2003) An individual with cerebral palsy and typical intelligence can learn to suppress these reflexes, but the reflex might resurface under certain conditions such as during an extreme startle reaction. Reflexes may also be limited to those areas affected by the atypical neurology, such as individuals whose cerebral palsy affects only their legs retaining the Babinski reflex but having normal speech. In individuals with hemiplegia, the reflex might be seen in the foot on the affected side only. We shall now consider the newborn reflex behaviours.
Moro Reflex
Moro reflex
This is sometimes referred to as the startle reflex, startle response, or embrace reflex. It is more commonly known as the Moro response or Moro reflex as it was discovered and first described by Austrian pediatrician Ernst Moro (1874-1951). Moro reflex is one of the infantile reflexes. It may be observed in incomplete form in premature birth after the 28th week of gestation, and is usually present in complete form by week 34 (third trimester). It is normally present in all infants/newborns up to 4 or 5 months of age though it may last up to six months. Persistence of the Moro response beyond 4 or 5 months of age is noted only in infants with severe neurological defects. This reflex is a response to unexpected loud noise or when the infant feels like, it is falling. It is believed to be the only unlearned fear in human newborns. The primary significance of this reflex is in evaluating integration of the central nervous system (CNS), since the reflex involves 4 distinct components: startle, spreading out the arms (abduction), outspreading the arms (adduction) and crying (usually). It is likely to occur if the infant's head suddenly shifts position, the temperature changes abruptly, or they are startled by a sudden noise. The legs and head extend while the arms jerk up and out with the palms up and thumbs flexed. Shortly afterward, the arms are brought together and the hands clench into fists, and the infant cries loudly. Absence of the reflex on both sides of the body (bilateral) may mean damage to the infant's central nervous system while a unilateral absence could mean an injury due to birth trauma such as a fractured clavicle or injury to the brachial plexus. The brachial plexus is an arrangement of nerve fibres, running from the spine, specifically from above the fifth cervical vertebra to underneath the first thoracic vertebra. It proceeds through the neck, the axilla (armpit region) and into the arm. Erb's Palsy (Erb-Duchenne Palsy, or Brachial plexus paralysis) is a condition which, mainly due to birth trauma, can affect 1 or all of the 5 primary nerves that supply the movement and feeling to an arm. The palsy can recover fully without intervention, or may require surgical correction. The most common cause of Erb’s palsy is an abnormal or difficult childbirth or labour. For example, it can occur if the infant's head and neck are pulled toward the side at the same time as the shoulders pass through the birth canal (Rauch, 2006)
The condition can also be caused by excessive pulling on the shoulders during a vertex delivery (head first) or by pressure on the raised arms during a breech delivery (feet first)( Rauch, 2006).
Walking/Stepping Reflex
Walking Reflex
The walking or stepping reflex is present at birth; though infants are still can not support their own weight, when the soles of their feet touch a flat surface they will attempt to 'walk' by placing one foot in front of the other. This reflex disappears as an automatic response and reappears as a voluntary behavior at around eight months to a year old.
Rooting Reflex
The rooting reflex is present at birth and assists in breastfeeding, disappearing at around four months of age as it gradually comes under voluntary control. A newborn infant will turn their head toward anything that strokes their cheek or mouth, searching for the object by moving their heads in steadily decreasing arcs until the object is found. After becoming used to responding in this way (if breastfed, approximately three weeks after birth), the infant will move directly to the object without a "search".
Sucking reflex
The sucking reflex is common to all mammals and is present at birth. It is linked with the rooting reflex and breastfeeding, and causes the child to instinctively suck at anything that touches the roof of their mouth. There are two stages to the action: First, Expression: activated when the nipple is placed between a child's lips and touches their palate. They will instinctively press it between their tongue and palate to draw out the milk. Secondly, Milking during which the tongue moves from areola to nipple, coaxing milk from the mother to be swallowed by the child. Coordination on of these movements with breathing and swallowing is instinctual, but not perfect.
Tonic neck reflex
Tonic Neck Reflex
The tonic neck reflex, asymmetric tonic neck reflex or 'fencing posture' is present at birth and disappears at around four months. When the child's head is turned to the side, the arm on that side will straighten and the opposite arm will bend (sometimes the motion will be very subtle or slight). If the infant is unable to move out of this position or the reflex continues to be triggered past six months of age, the child may have a disorder of the upper motor neurons.
Palmar Grasp Reflex
Grasp Reflex
The palmar grasp reflex appears at birth and persists until five to six months of age. When an object is placed in the infant's hand and strokes their palm, the fingers will close and they will grasp it. The grip is strong but unpredictable; though it may be able to support the child's weight, they may also release their grip suddenly and without warning. The reverse motion can be induced by stroking the back or side of the hand.
Plantar reflex
The plantar reflex or plantar grasp is present at birth and fades around the infant's first birthday. The plantar reflex causes the infant's toes to curl up tightly when something rubs the ball of their foot.
Babinski reflex
Often confused with the plantar reflex, the Babinski reflex is also present at birth and fades around the first year. The Babinski reflex appears when the side of the foot is stroked, causing the toes to fan out and the hallux (big toe) to extend. The reflex is caused by a lack of myelination in the corticospinal tract in young children. The Babinski reflex is a sign of neurological abnormality in adults.
Galant reflex
Galant Reflex
The galant reflex, also known as Galant’s infantile reflex, is present at birth and fades between the ages of four to six months. When the skin along the side of an infant's back is stroked, the infant will swing towards the side that was stroked. If the reflex persists past six months of age, it is a sign of pathology. The reflex is named after the Russian neurologist Johann Susman Galant.
Motor Development
During the first 3 months of life, infants being to gain control over their body movements. Reflex behaviours are indications of neurological maturation. Primitive reflexes drop out during the first year as voluntary, cortical control develops. Primitive reflexes are reflex actions originating in the central nervous system that are exhibited by normal infants Self-locomotion seems to be a “setting event”, effecting changes in all domains of development. The Denver Developmental screening Test is widely used to assess motor, linguistic, and personality and social development.
Experiments with the visual cliff suggest that depth perception is present very early in life. It may depend in part on control of the head and on eye-hand coordination, which permits haptic perception. Environment factors, including cultural patterns, may affect the pace of motor development. Extreme environmental deprivation can slow development, at least temporarily, and training or practice can accelerate certain specific skills.
Health
A small minority of infants suffer lasting effects of birth trauma, sometimes due to anoxia. Other complications include low birthweight, postmature birth, and stillbirth. Low-birthweight babies may be either preterm (premature) infants or small-for-date (small-for-gestational age) infants. Low birthweight is a major factor in infant mortality and can cause long-term physical or cognitive problems. Electronic fetal monitoring is widely used (and may be overused) during labour and delivery to detect signs of fetal distress, especially in high-risk births.
At a minute and 5 minutes after birth, the neonate is assessed by the Apgar scale to determine how well he or she is adjusting to extrauterine life. The Brazelton Neonatal Behavioural Assessment Scale may be given to assess responses to the environment and to predict future development. Although the infant mortality rate in Nigeria has improved, it is still disturbingly high. Rates of immunization have also improved in many parts of Nigeria but there is still a need to achieve more success in this regard.
Newborns and Their Parents
Researchers following the ethological approach have suggested that similar to imprinting in some animals – there is a critical period for the formation of the mother-infant bond. However, research has not confirmed this hypothesis. Fathers typically bond with their babies whether or not they are present at the birth. A newborn’s state of arousal is governed by periodic cycles of wakefulness, sleep, and activity, which seem to be inborn. Sleep takes up the major (but a diminishing) amount of a neonate’s time. Newborns’ activity levels show stability and may be early indicators of temperament. Marital satisfaction often declines after the birth of a first baby. Expectations and sharing of tasks can contribute to a marriage’s deterioration or improvement. Dual earner couples have a particularly difficult challenge but this can be resolved through mutual agreement between the couples.
A child’s body grows most dramatically during the first year of life; growth proceeds at a rapid but diminishing rate during the next 2 years. Normal physical growth and motor development proceed according to the cephalocaudal and proximodistal principles. Breastfeeding offers many physiological and psychological benefits to the infant. However, the quality of the relationship between parents and baby is the most important element in promoting healthy psychological development. During the latter half of the first year, babies may begin to eat solid foods. Obesity in infancy does not necessarily predict obesity later in life. Much of the brain’s growth after birth consists of the formation of synapses, or connections between nerve cells. Due to the brain’s plasticity, especially during this critical period of growth, environmental experience can influence brain development positively or negatively.
Early Sensory Capacities
Sensory capacities, present from birth and even in the womb, develop rapidly in the first months of life. Very young infants show pronounced abilities to discriminate between stimuli. Touch seems to be the first sense to develop and is the most mature sensory system for the first several months. Newborns are sensitive to pain, smell, taste, and hearing begins to develop in the womb. A preference for sweet taste seems to be inborn and probably helps infants adapt to life outside the womb. Odor preferences develop with experience. Vision is the least well developed sense at birth. Peripheral vision, color perception, acuteness of focus, binocular vision, and the ability to follow a moving object with the eyes all develop within the first few months. Visual preference and auditory discrimination appear to be related to later cognitive functioning.
Reflex behaviours
Reflex behaviours are indications of neurological maturation. Primitive reflexes drop out during the first year as voluntary, cortical control develops.
Primitive reflexes are reflex actions originating in the central nervous system that are exhibited by normal infants but not neurologically intact adults, in response to particular stimuli. These reflexes disappear or are inhibited by the frontal lobes as a child moves through normal child development. (Rauch, 2006). These primitive reflexes are also called infantile, infant or newborn reflexes. Older children and adults with atypical neurology (for instance, people with cerebral palsy) may retain these reflexes and primitive reflexes may re-appear in adults due to certain neurological conditions including, but not limited to, dementia, traumatic lesions, and strokes (Schott and Rossor, 2003) An individual with cerebral palsy and typical intelligence can learn to suppress these reflexes, but the reflex might resurface under certain conditions such as during an extreme startle reaction. Reflexes may also be limited to those areas affected by the atypical neurology, such as individuals whose cerebral palsy affects only their legs retaining the Babinski reflex but having normal speech. In individuals with hemiplegia, the reflex might be seen in the foot on the affected side only. We shall now consider the newborn reflex behaviours.
Moro Reflex
Moro reflex
This is sometimes referred to as the startle reflex, startle response, or embrace reflex. It is more commonly known as the Moro response or Moro reflex as it was discovered and first described by Austrian pediatrician Ernst Moro (1874-1951). Moro reflex is one of the infantile reflexes. It may be observed in incomplete form in premature birth after the 28th week of gestation, and is usually present in complete form by week 34 (third trimester). It is normally present in all infants/newborns up to 4 or 5 months of age though it may last up to six months. Persistence of the Moro response beyond 4 or 5 months of age is noted only in infants with severe neurological defects. This reflex is a response to unexpected loud noise or when the infant feels like, it is falling. It is believed to be the only unlearned fear in human newborns. The primary significance of this reflex is in evaluating integration of the central nervous system (CNS), since the reflex involves 4 distinct components: startle, spreading out the arms (abduction), outspreading the arms (adduction) and crying (usually). It is likely to occur if the infant's head suddenly shifts position, the temperature changes abruptly, or they are startled by a sudden noise. The legs and head extend while the arms jerk up and out with the palms up and thumbs flexed. Shortly afterward, the arms are brought together and the hands clench into fists, and the infant cries loudly. Absence of the reflex on both sides of the body (bilateral) may mean damage to the infant's central nervous system while a unilateral absence could mean an injury due to birth trauma such as a fractured clavicle or injury to the brachial plexus. The brachial plexus is an arrangement of nerve fibres, running from the spine, specifically from above the fifth cervical vertebra to underneath the first thoracic vertebra. It proceeds through the neck, the axilla (armpit region) and into the arm. Erb's Palsy (Erb-Duchenne Palsy, or Brachial plexus paralysis) is a condition which, mainly due to birth trauma, can affect 1 or all of the 5 primary nerves that supply the movement and feeling to an arm. The palsy can recover fully without intervention, or may require surgical correction. The most common cause of Erb’s palsy is an abnormal or difficult childbirth or labour. For example, it can occur if the infant's head and neck are pulled toward the side at the same time as the shoulders pass through the birth canal (Rauch, 2006)
The condition can also be caused by excessive pulling on the shoulders during a vertex delivery (head first) or by pressure on the raised arms during a breech delivery (feet first)( Rauch, 2006).
Walking/Stepping Reflex
Walking Reflex
The walking or stepping reflex is present at birth; though infants are still can not support their own weight, when the soles of their feet touch a flat surface they will attempt to 'walk' by placing one foot in front of the other. This reflex disappears as an automatic response and reappears as a voluntary behavior at around eight months to a year old.
Rooting Reflex
The rooting reflex is present at birth and assists in breastfeeding, disappearing at around four months of age as it gradually comes under voluntary control. A newborn infant will turn their head toward anything that strokes their cheek or mouth, searching for the object by moving their heads in steadily decreasing arcs until the object is found. After becoming used to responding in this way (if breastfed, approximately three weeks after birth), the infant will move directly to the object without a "search".
Sucking reflex
The sucking reflex is common to all mammals and is present at birth. It is linked with the rooting reflex and breastfeeding, and causes the child to instinctively suck at anything that touches the roof of their mouth. There are two stages to the action: First, Expression: activated when the nipple is placed between a child's lips and touches their palate. They will instinctively press it between their tongue and palate to draw out the milk. Secondly, Milking during which the tongue moves from areola to nipple, coaxing milk from the mother to be swallowed by the child. Coordination on of these movements with breathing and swallowing is instinctual, but not perfect.
Tonic neck reflex
Tonic Neck Reflex
The tonic neck reflex, asymmetric tonic neck reflex or 'fencing posture' is present at birth and disappears at around four months. When the child's head is turned to the side, the arm on that side will straighten and the opposite arm will bend (sometimes the motion will be very subtle or slight). If the infant is unable to move out of this position or the reflex continues to be triggered past six months of age, the child may have a disorder of the upper motor neurons.
Palmar Grasp Reflex
Grasp Reflex
The palmar grasp reflex appears at birth and persists until five to six months of age. When an object is placed in the infant's hand and strokes their palm, the fingers will close and they will grasp it. The grip is strong but unpredictable; though it may be able to support the child's weight, they may also release their grip suddenly and without warning. The reverse motion can be induced by stroking the back or side of the hand.
Plantar reflex
The plantar reflex or plantar grasp is present at birth and fades around the infant's first birthday. The plantar reflex causes the infant's toes to curl up tightly when something rubs the ball of their foot.
Babinski reflex
Often confused with the plantar reflex, the Babinski reflex is also present at birth and fades around the first year. The Babinski reflex appears when the side of the foot is stroked, causing the toes to fan out and the hallux (big toe) to extend. The reflex is caused by a lack of myelination in the corticospinal tract in young children. The Babinski reflex is a sign of neurological abnormality in adults.
Galant reflex
Galant Reflex
The galant reflex, also known as Galant’s infantile reflex, is present at birth and fades between the ages of four to six months. When the skin along the side of an infant's back is stroked, the infant will swing towards the side that was stroked. If the reflex persists past six months of age, it is a sign of pathology. The reflex is named after the Russian neurologist Johann Susman Galant.
Motor Development
During the first 3 months of life, infants being to gain control over their body movements. Reflex behaviours are indications of neurological maturation. Primitive reflexes drop out during the first year as voluntary, cortical control develops. Primitive reflexes are reflex actions originating in the central nervous system that are exhibited by normal infants Self-locomotion seems to be a “setting event”, effecting changes in all domains of development. The Denver Developmental screening Test is widely used to assess motor, linguistic, and personality and social development.
Experiments with the visual cliff suggest that depth perception is present very early in life. It may depend in part on control of the head and on eye-hand coordination, which permits haptic perception. Environment factors, including cultural patterns, may affect the pace of motor development. Extreme environmental deprivation can slow development, at least temporarily, and training or practice can accelerate certain specific skills.
Health
A small minority of infants suffer lasting effects of birth trauma, sometimes due to anoxia. Other complications include low birthweight, postmature birth, and stillbirth. Low-birthweight babies may be either preterm (premature) infants or small-for-date (small-for-gestational age) infants. Low birthweight is a major factor in infant mortality and can cause long-term physical or cognitive problems. Electronic fetal monitoring is widely used (and may be overused) during labour and delivery to detect signs of fetal distress, especially in high-risk births.
At a minute and 5 minutes after birth, the neonate is assessed by the Apgar scale to determine how well he or she is adjusting to extrauterine life. The Brazelton Neonatal Behavioural Assessment Scale may be given to assess responses to the environment and to predict future development. Although the infant mortality rate in Nigeria has improved, it is still disturbingly high. Rates of immunization have also improved in many parts of Nigeria but there is still a need to achieve more success in this regard.
Newborns and Their Parents
Researchers following the ethological approach have suggested that similar to imprinting in some animals – there is a critical period for the formation of the mother-infant bond. However, research has not confirmed this hypothesis. Fathers typically bond with their babies whether or not they are present at the birth. A newborn’s state of arousal is governed by periodic cycles of wakefulness, sleep, and activity, which seem to be inborn. Sleep takes up the major (but a diminishing) amount of a neonate’s time. Newborns’ activity levels show stability and may be early indicators of temperament. Marital satisfaction often declines after the birth of a first baby. Expectations and sharing of tasks can contribute to a marriage’s deterioration or improvement. Dual earner couples have a particularly difficult challenge but this can be resolved through mutual agreement between the couples.
Adapted from Developmental Psychology by Grace A. Adejuwon Ph.D Department of Psychology University of Ibadan
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