Birth, Newborns, and Early Infancy PSYC 206: Life-Span Development Lecture 4 Aylin Küntay

Birth ~ 38 weeks after fertilization, triggered by a signal from an area of the fetus that monitors organ development labor starts when the muscles of the uterus start to contract rhythmically, first every 15-20 minutes, then at shorter and shorter intervals. 3 stages of labor dilation of the neck of the uterus delivery of the baby expulsion of the placenta

Birth: The First Bio-Social-Behavioral Shift

Complications and risks inability to breathe out of the water world, the baby must initiate and maintain breathing failure to breathe prevents the delivery of oxygen, leading to anoxia-- a deficit of oxygen supply to the cells that can produce tissue damage e.g., cerebral palsy, where the area that controls the movement of the limbs is affected low birthweight can be because born preterm, before the normal gestation period of 38 weeks < 2,500 gm.s, for full term infants

Physical and behavioral assessment tests to screen babies for disorders, to determine whether their nervous system is intact, and to characterize how a newborn responds to social and physical stimuli Apgar test: focuses on 5 of the newborn’s vital functions which are measured by heart rate, respiration, muscle tone, response to a mildly painful stimulus, and skin color receives a score from 0 to 2 on each of these items with 2 the optimal score used to discover babies who may need special monitoring and attention

Apgar Scoring System Rating (at 1 & 5 minutes after birth) Vital Sign 1 2 Heart rate Absent Slow (<100) Over 100 Respiratory effort Slow, irregular Good, crying Muscle tone Flaccid Some flexion of extremities Active motion Reflex responsivity No response Grimace Vigorous cry Color Blue, pale Body pink, extremities blue Completely pink

Brazelton Neonatal Behavioral Assessment Scale Includes tests of infant reflexes, motor capacities, muscle tone, capacity for responding to objects and people, capacity to control own behavior, attention Orientation to animate objects (visual/auditory) Pull-to-sit (e.g., try to right his head) Cuddliness (e.g., resist, passive, tries to cuddle) Defensive movements (e.g., try to remove cloth from face) Self-quieting activity (e.g., suck thumb, look around)

Premature Birth Born before 37th week More likely in twins, very young mothers, women who smoke or are under-nourished

Consequences of Premature Birth Immaturity of the lungs (leading cause of death among preterm infants), as well as of their digestive and immune systems Premature babies who are of normal size for their gestational age stand a good chance of catching up with full-term babies However, some children born prematurely have problems with maintaining attention and with visual-motor coordination when they are school age

Low Birth Weight Typical weight at birth: 7 to 7½ lbs. Causes of fetal growth retardation Multiple births; intrauterine infections; placenta abnormalities; maternal smoking, use of narcotics, or malnutrition Developmental consequences Two-thirds of deaths that occur in the period immediately following birth are among low-birth-weight infants 3x more likely to have neurologically-based developmental handicaps Decrease in intellectual capacities in childhood However, babies who are raised in good SES circumstance with an intact family and a mother with good education are less likely to suffer negative effects from their condition at birth than children raised without these benefits

Neural/Brain Development in Babies

Neural Networks in Postnatal Life

Experience and Development Synaptic pruning Exuberant synapto-genesis

Some newborn reflexes equipped with automatic and stereotyped behavior patterns that occur in response to specific stimuli the presence or absence of reflexes and their developmental course provides info about the baby’s neural development the rooting reflex: if one strokes a newborn’s cheek next to the side of the mouth, the baby will turn the head to that side and search with the mouth disappears around 3 to 4 months of age

Some newborn reflexes the palmar reflex: enables the newborn to hang unsupported when apply pressure against the palm of the hands the moro reflex: a series of reactions to a sudden sound or the loss of head support. The infant thrusts her arms outward, opens her hands, arches her back, and stretches her legs outward. Then she brings her arms inward in an embracing motion with fingers formed into fists absence and its failure to disappear after 6-7 months is a sign of brain damage

Some newborn reflexes Babinski reflex: when the sole of the foot is stroked, the toes fan out and curl Crawling reflex: when the baby is placed on the stomach and soles of his feet are touched, his arms and legs move rhythmically Stepping reflex: when the baby is held upright over a flat surface, he makes rhythmic leg movements

Grasping Reflex When a finger or some other object is pressed against the baby’s palm, the baby’s fingers close around it Disappears in 3-4 months; replaced by voluntary grasping

Perceptual development What does the world look like to a newborn infant? How can we find out what they see and hear? How can we study infant perception? Do they see shapes and faces the way we do? Can they recognize their mother’s face? How about their color perception?

Sensory Processes Normal full-term newborns enter the world with all sensory systems functioning, but not all of these systems have developed to the same level due to different developmental rates (i.e., heterochrony) Indications of sensation Turning of the head, variation in brain waves, changes in rate of sucking on a nipple Habituation: Becomes bored and stops attending Dishabituation: Interest is renewed after the infant perceives a change in the stimulus

Earliest sensory processes & organized behaviors as opposed to the views of earlier century thinkers (e.g., John Locke’s tabula rasa or William James’ blooming, buzzing confusion),babies enters the world with some well-organized behaviors sensory capacities: visual, auditory, taste-related, and tactile capacities are all functioning but, some capacities are more mature than others looking, sucking, and crying are 3 behaviors that, unlike reflexes, are often not elicited by a discrete, identifiable stimulus Eleanor Gibson many perceptual capacities are built-in adult-like by 6 months

How to measure sensory reactions? measure their reaction to stimuli does a baby turn her head in the direction of a sound? habituation paradigm: relies on infants’ tendency to pay less and less attention to a repeatedly presented stimulus (habituation) if the stimulus is changes in a way that makes it seem new to the infant, he will once again pay attention (dishabituation)

Early hearing Head-turning: studies the extent to which infants turn their heads toward a sound source (Weiss et al.) minutes-old infants can localize sound sources in space High-amplitude sucking :(part of the habituation paradigm). Have sucking trigger a sound, get babies reduce their sucking (habituation), introduce another sound, observe if they start sucking vigorously again

Hearing Infants can distinguish the sound of the human voice from other kinds of sounds, and seem to prefer it Are particularly interested in speech with the high pitch and slow, exaggerated pronun- ciation (i.e., “baby talk”) Evidence that by 2 days old, some babies would rather hear the language that has been spoken around them than a foreign language

Sound perception Eimas et al., Jusczyk: infants as young as 2 months old can perceive phonemic distinctions, e.g., difference between /ba/ and /pa/ categorical sound perception is innate Not only from the native language, but also from other languages Japanese babies will perceive the difference between /r/ and /l/, even though adult speakers cannot but after 8 months or so: ability to distinguish nonnative sounds diminishes

New Consonant Both groups hear a consonant sound Habituate Experimental group hears a new consonant sound at time marked 0 Infants are able to distinguish consonant sounds

Visual perception from the first days of life, awake babies can distinguish light intensity open their eyes widely in darkness and close them in bright light; they prefer moderate light levels (Haith) visual acuity: how sharply he can see things the newborn’s vision is nearsighted: estimated to be 20/400 to 20/800… that is, they can see at 20 feet what a normal adult vision can see at 400 feet to 800 feet color vision: at birth, they can distinguish between red and green adult-like functioning in all three types of cones (color-sensitive receptors for red, blue, and green) is present by 2 months of age

Fantz Looking Chamber (1960s) Demonstrated that babies less than 2 days old can distinguish among visual forms Tend, however, to focus on areas of high contrast, such as lines and angles

Visual preference (Fantz) Fantz discovered that infants look at different things for different lengths of time placed infants in a looking chamber, which had two visual displays on the ceiling above the infant’s head an experimenter looked through a peephole and measured the length of fixation of the infant’s eyes on each of the displays 2 day olds preferred to look at patterns rather than at colored circles it is likely that pattern perception has an innate basis, or at least acquired after only minimal environmental experience

Perception of faces Fantz’s study shows that infants prefer to look at the schematic human face more than any other display another Fantz study compared the preference to look at a schematic human face where all the features are arranged properly a schematic face where the features are scattered around a figure that does not have the facelike features

Scanning the human face Maurer and Salapatek showed human faces to 1- and 2-month old infants by a special mirror arrangement, the faces were projected as images in front of the infants’ eyes so that eye movements could be photographed 1-month olds concentrated on the outer contour of the face, while the 2-month olds spent more time examining the internal details of the face scanning results for quiet vs. talking faces

Perception of Faces Infants show a preference for patterned stimuli over plain stimuli Babies as young as 9 minutes old will look longer at a schematic moving face than a scrambled one

Visual Preferences of Infants

Taste sensitivity to taste may be present before birth when saccharin was added to the amniotic fluid of a near-term fetus, increased swallowing was observed newborns prefer sweet substances than plain water-- suck longer with fewer pauses Rosenstein and Oster showed that babies made different facial expressions when they tasted sweet, sour, and bitter solutions

Smell newborns can differentiate odors by the expression on their faces, they like the way vanilla and strawberry smell, but not how rotten eggs and fish smell (Steiner) MacFarlane showed that 6-day-old infants showed a clear preference for smelling their mother’s breast pad soaked with their mother’s milk compared to a clean breast pad 2 day old infants do not show such a preference

Touch and Pain a touch to the cheek produces the turning of the head and a touch to the lips produces a sucking response increased crying and fussing occur during circumcision of 3 year olds, which indicates that they experience pain for many years, doctors have performed operations on newborns without anesthesia recent research has demonstrates that they do feel pain

Infant Expression of Emotions Joy Anger Sadness Disgust Distress Interest Fear Surprise

Temperament Three broad categories Easy babies: Playful, regular in their biological functions, adapt readily to new circumstances Difficult babies: Irritable, irregular in their biological functions, often respond intensely and negatively to new situations or try to withdraw from them Slow-to-warm-up babies: Low in activity level, responses are typically mild, tend to withdraw from new situations, require more time than easy babies to adapt to change Moderate temperamental stability over first 8 years of childhood Impact of both genetic and environmental components