CH 4 Developmental Psych; Development in Health in Infants and Toddlers

Ch 4: How to establish regular sleeping, waking, and feeding routines; the health need of infants; patterns of growth in body and brain; motor, sensory, and perceptual developments

What are the 5 states of newborn arousal and their durations?

Quiet NREM— 9 hrs; full rest, low body activity and relaxed
Active REM— 9 hrs; slow movements in sleep, active brain sleep (critical for brain development)
Quiet Alertness— 2.5 hrs; slight body activity, relaxed and bright eyes. Responsive to external stimuli
Waking activity & Crying— 2.5 hrs; crying and lots of movement
Drowsiness— 1 hr; glazed eyes, body movements more than NREM but less than REM

How many hours does an infant sleep per day? And in what intervals?

18 hours

2-3 hr naps driven mostly by hunger

Why is REM sleep important for infants?

(~50% of sleep is REM for newborns, 80% for preterm babies)
REM is when brain is stimulated periodically to grow

How is the feeding cycle a dynamic structure between mother and the infant? Between the father?

They are both influencing each other:

prolactin: produces more milk

oxytocin: baby’s rooting, sucking, crying triggers this which “lets-down” the milk

Fathers show hormonal changes echoing mothers when holding baby or when baby is crying!

What nerve does breastfeeding activate compared to bottle-feeding?

Breastfeeding encourages higher-frequency sucking, which activates the Vagus Nerve

The Vagus Nerve: main highway between brains and organs

It is part of the parasympathetic nervous system “rest & digest”

Promotes greater capacity for self-regulation at a physiological level!

• ex. slowing or speeding heart rate as needed

What is Colic and why does it happen?

Colic refers to when an infant cries for long periods of time

This is due to individual differences in babies’ abilities to self-soothe or respond to soothing stimuli

Are there benefits or risks to co-sleeping?

longitudinal study over 18 years showed no major positive or negative outcomes, most studies done in WEIRD nations where its not common

Immediate risks include suffocation

What is graduated extinction sleeping technique and is it better than other sleeping techniques

Gradually increasing the length of time before responding to crying babies, offering VERBAL support but not holding them.

Basically teaches them that you are there but not reinforcing their crying.

short term benefits:

• increased feelings of secuirty from child

• reduced irritability

• fewer behavior problems during the day

high and roughly equal rate of success with camping and faded bedtime techniques!

what is SUDDEN INFANT DEATH SYNDROME?

SDIS refers to infants who die during sleep with no apparent cause

(Although it is linked to a few reasons like heart failure and suffocation)

Factors that may contribute to it:

• stomach sleeping → increases risk of suffocation

• neurological defects and physical abnormalities that affect/regulate sleep in the brain, breathing, and other automatic body functions

• exposure to prenatal toxins, low birth weight, siblings who died from SDIS

What is the Triple Risk Hypothesis?

The Triple Risk Hypothesis gives 3 reasons for SDIS

• biological vulnerability due to one or more risk factors (neurological defects, physical abnormalities, genetics, prenatal toxins, low birth weight)

• under 6 MONTHS of age (time when infants go through quick phases of growth that can change how well the body regulates and controls itself)

• exposed to stressors that impact breathing like hot room, smoke, respiratory infection, sleeping position.

Until when is breastfeeding recommended? (Give me specifics like exclusive, weaning, etc.)

recommended exclusively for 6 months

after that, can start introducing solids but can go up to 24 months and should continue through 12 months

What are the short-term benefits of breastfeeding? What is the problem of believing these?

• lower risk of gastrointestinal and respiratory diseases

• fewer allergic reactions

• lower rates of middle ear infection

• possibly linked to lower rates of childhood obesity

• lower likelihood of intestinal disease and SIDS

for mothers:

• faster shrinking of uterus

• reduced blood loss after childbirth

• a slightly lower risk of postpartum depression

These are all correlational!!! Not causational!!

What are the long-term benefits of breastfeeding?

• slightly lower rates of obesity and diabetese

• Higher average IQ!!!

  • higher concentrations of long-chain polyunsaturated fatty acids in breast milk than formula

WHen can new food start to be introduced in infants? And how should you do it?

Around 6 months

Should introduce one food at a time, for extended period of days incase of digestion problems or allergies.

Offering the same food everyday for a few days and offering related food can help them be less picky eaters.

Growth of the body and brain in the first 2 years follows these 2 patterns:

Cephalocaudal pattern: “head to tail” head grows more rapidly than the rest of the body

Proximodistal pattern: “near to far” growth happens center of body and ooutwards

Is growth constant or irregular? What is it called?

Growth is irregular.

Saltatory growth “growth spurts” happen and infants took longer naps before saltation days!

Psychological stress can delay or hamper saltations!

Components of a neuron

Dendrites → receive message

Cell body → generates electrical impulse

Axon → carries electrical impulses to other neurons

neurotransmitters (chemical messengers) cross synapse to receiving neuron

Three important processes of brain development

synaptogensis

pruning

myelination

Describe Synaptogenesis

Formation of new synapses!

In the first 6 months, dendrites grow vigorously and many new synapses form

Actually, in the first 24 months, synapse reaches peak—about 50% more than in adult brains!

Describe Pruning

Unused synapses get pruned out…

Are synaptogensis and pruning the same in every area of the brain?

No, they happen in waves that follow different developmental courses depending on the location in the brain!

• visual and auditory cortex reach peak faster than prefrontal cortex (goes back to piaget’s stages of development, sensorimotor first and then operational stages, and basically the idea that infants learn sensory and surroundings before higher thinking)

What disorder/syndrome happens when dendrites fail to grow and synapses fail to form?

Down Syndrome

What disorder/syndrome happens when there is an excess of dendrites and faliure to prune out synapses?

Autism Spectrum Disorder

Describe Myelination

Created insulation layer of fat that allows for faster neural conduction and communication!

Occurs rapidly in the first year—why high fat diet is recommended for newborns

When brain is fully myelinated, brain loses plasticity—so better learn skills fast!

Thicker myelin can form from select experiences!

What is serve and return action and how does it shape brain circuitry?

Baby “serves” through babbling and facial expressions

Adult “returns” and responds to them

→ heps create neural connections and emotional and cognitive interactions later in life

Describe brain area development in the first 2 years

1st year → most rapid growth in Broca’s and Wernicke’s, as well as occipital and temporal-occiptal lobes, and insula (bodily and emotional awareness)

2nd year → parietal, frontal, and hippocampus

What are the two ways experience shapes brain through neuroplasticity? (expectant and dependent)

Experience-expectant brain development:

• Brain is biologically prepared by producing many synapses to receive expected or common experiences during sensitive periods which are then pruned

Experience-dependent brain development:

• New synapses are formed in response to the unique experiences of the individual, such as playing an instrument and speaking a language

• Pruning still happens, based on continuous experiences (not speaking a language for some time can degenerate synapses)

What shapes a baby’s motor development?

brain & body developments
+
specific experiences
+
cultural practices

How do infants use reflexes?

Fixed motor actions (unconcsious) in response to stimuli, newborns have reflexes to help them survive

These fade over the first few months as reflexes shift to intentional control

How does the dynamic systems theory fit into children’s motor skill development?

Motor development is very plastic to environmental influences and is variable across infants!

Influenced by:

• goals of the child

• change in postural control and movement capacities

• brain development

• amount of practice and environmental support

When is it customary to start potty training in the U.S.? Is this the case in other cultures? Is it good for the baby?

U.S. → 18-36 months

Thailand → 4-12 months

Vietnam → 2 years

Half of the world’s babies NEVER wear diapers and are potty trained by 12 months of age

• infants trained with AITT achieved complete emptying of bladder by 9 months of age in contrast with Western babies at 2 years of age

• at risk for UTI

• Before 12 months/earlier the better!

another study

• initiating rigid toilet training prior to 24 months or delaying it past 36 both correlated with an increased risk of daytime wetting and constipation

• but also there is a difference between elimination communication and traditional intensive training

Elimination communication potty training vs. traditional intensive training. Which is better?

Coercive early training is problematic.

However, adults learning to recognize infant cues are safe and effect and allow children as young as 12 months to signal their needs and briefly withhold elimination.

Should we coddle the youth? By 2001, there was almost 4x an increase in peanut allergies. What causes such an increase in allergies?

• Hygiene, antibiotics, and too little outdoor play → children don’t get exposed to microbes as they once did. Leads them to develop immune systems that overreact to substances that aren’t actually threatening

• Shielding children in the same way to every possible risk might have similar effects on their growth

Antifragility Hypothesis: children are not fragile.

What is sensation vs. perception?

Sensation: process by which sensory receptors receive signals from environment and transmits them to the brain.

Perception: process of organizing and interpreting said signals.

What is the most highly developed sense at birth? What about least? Describe both.

Touch is the most developed at birth (ex. rooting, kangaroo care)

• infants can feel pain!

• experimenting with different shapes and textures good for brain stimulation and growth!

Vision is the least developed

• infants can distinguish light from dark but do not have high visual acuity yet (comes around 3 months)

• start to distinguish color ~4 months

What about taste/smell and hearing?

Taste/smell

• infants are born with a preference for flavors! Amniotic fluid contains flavor and odor molecules from mother’s diet

• preference for sweet over bitter

• prefer smell of mother over father or stranger

Hearing

• newborns are very responsive to sound when awake

• especially to human voices

• quiet > noisy environments for speech and language learning

• first 6 months acuteness of hearing improves a lot

Face perception in infants

• preference for familiar faces

• preference for own racial groups (due to perceptual narrowing experience which leads to other race effect)

• face recognition system remains plastic throughout childhood

• newborns scan contours of the face, and when visual acuity improves around 3 months, start to scan interior and facial expressions

What is stereopsis and its significance?

A depth cue

Cues from left and right eye for binocular depth and constructing 3D objects (3 months)

experience-expectant

What are pictoral cues and its significance?

Cues you can get from an image

Linear perspective, spatial depth, habituation and obscure objects, texture, influences size constancy

experience-dependent

How do infants learn locomotion?

• Infants have no fear of ledges and depth at first, crawls right over the edge

• infants with at least 2 weeks of crawling experience will attain fear of depth and become more accurate at judging

• Crawling DOES NOT transfer into walking!!!! Must re-learn because of differences in closeness to the ground and bodily stability

Describe what an infant sees at (1-3 months) (8-10 months) and (12-18 months) and how it translates into motor skills.

(1-3 months) → faces mostly; facial recognition

(8-10 months) → far away room clutter; statistical learning aka learning habituation and patterns through it

(12-18 months) → walking and freedom to use hands; word association with objects as they explore and point and interact