Human Development II Flashcards
What are the trends in Brain Development?
Brain is ~95% of adult size by age 6 – Importance of early intervention when
neurodevelopmental disorders are identified
• Two major changes occur throughout childhood, adolescence, and young adulthood:
1) Synaptic density shows an inverted U-shaped trajectory: Density increases until puberty then steady pruning throughout adolescence and adulthood
2) Continued myelination of certain brain regions
What’s the significance of synaptic density?
1) SYNAPTIC DENSITY
• Inverted U-shaped trajectory for gray matter volume
― Frontal and parietal gray matter peaks at age 12 in boys and 10 in girls (panels A & B)
― Later peak for temporal gray matter at age 16
White Matter • Linear increase in white matter volume (Panel D) ― Axons, myelin, glial cells ― Decline in white matter starts in ~40s
What’s the significance of myelination?
MYELINATION
• White matter myelination proceeds in a regionally-specific manner
― Earliest areas: primary motor and sensory
― Latest regions: prefrontal, temporal, and parietal association areas (up through at least 3rd decade)
― The development of more complex
cognitive functioning is supported by
regions with ongoing myelination
(particularly long-range association pathways and the frontal lobes)
What are the features of physical development in early childhood?
- Slow down in physical growth
- Decreased appetite
• Sphincter control (age3-5yrs)
– Bowel control problems ≥ age 4: Encopresis
– Bladder control problems ≥ age 5: Enuresis
• Improved gross motor and fine motor development
– Stacks blocks – age x 3
• 18 mos (3 blocks); 2 yrs (6 blocks); 3 yrs (9 blocks)
– Hops on one foot (age 4)
– Self-grooms and self-dresses (age 4-5)
• Handedness established (by age 6-7)
Summarize the pre-operational (Pre-logical)of Piaget stages
2-7 years
Representations – objects represented by words or images
• Ability to pretend
• Egocentric thought processes predominate
– Difficulty taking other’s perspectives
What is the pre-operational stage?
Pre-operational:
• Basic mental reasoning
• Law of conservation (compensation
abilities) not yet achieved
- Symbolic thinking expands
* The use of symbols or internal images to represent objects, persons, and events (e.g., a child using a stick as a pretend sword)
What are the features of cognitive development in early childhood?
Longer attention span; 5-15 minutes
• Organize objects by size and shape
• Visuospatial Skills (e.g., drawing shapes)
Expansion of language skills (especially from ages 3-5)
– Uses 900 words (age 3) – Sentences
• Sentence Lengths: 3-words (3 years); 4-words (4 years); 5-word (5 yrs) • Uses plurals, pronouns, and compound sentences – Can tell stories and name colors – Asks the meaning of words – 90% intelligible by age 5
Describe emotional development in early childhood
• Struggle for autonomy and separateness from parents (separation/individuation)
• Development of secondary emotions (3 years)
– embarrassment, jealousy, pride, shame, guilt, envy
• Development of basic emotion regulation
– through observing others, talking about
emotion, self-soothing techniques
• Nightmares, fears (e.g., monsters)
What are the social development features of the early childhood?
Gender identity (by age 3)
• Increased interaction (especially from
ages 3-4)
– Understands turn-taking, sharing, and other social rules
– Cooperative play
– Imaginary play and imaginary friends
• Influence of Peers (age 5)
– Social conformity
– Romantic feelings for other
Describe physical development in middle childhood?
• Slow and steady height/weight increase (6 cm/3 kg per year)
– Boys start to weigh more than girls
• Permanent teeth (most by 11 years)
• Refined motor dexterity, speed, coordination
– Ride bicycle
– Write in print and cursive
Describe the cognitive development of middle childhood
PIAGET’s STAGES: Concrete operational stage
(logical thinking) 7-12 years
– Law of conservation: Compensation abilities achieved
– Seriation: Ability to sort stimuli by a characteristic (e.g.,
size)
– Transitivity: Ability to infer relations among elements in a serial order (e.g., If I am taller than Jane, and Jane is taller than Sue, then I am taller than Sue)
• Mental manipulation of objects and processes
• Logical thinking about objects and events but it is still
concrete logic
• Less egocentric and more relational
Summarize cognitive development of middle childhood
Understanding of death (age 8)
• Mnemonic strategies (e.g., rehearsal,
categorization)
• Language
– Shift from egocentric to social speech
– Vocabulary expansion (50,000 words by age 12)
Describe emotional development in middle childhood
• Languagedevelopmentfacilitates:
– Cognitive regulation of emotion (i.e., using
words rather than behavior to express self)
– Behavioral control (through self-talk)
• Internalization of social “display rules” guiding emotion expression (e.g., boys don’t show sadness; girls don’t show anger)
Describe social development in middle childhood
Perspective-taking
– Takes another perspective
– Simultaneously understands multiple perspectives on the same situation
• Understands fairness, generosity
• Competency/competition
– Children start to compare themselves to others
• Organized sport possible
– Focus is on learning “rules of the game”
– Understands value of being a team player
Explain physical development in adolescence
Puberty
– Increase in gonadal hormones
– Second “critical period” in sexual differentiation
– Secondary sex characteristics: breasts, pubic hair, facial hair, larynx enlargement/voice changes
Pubertal growth spurt
– Adolescents attain final 25% of adult height and 50% of adult weight
– Growth spurts earlier in girls than boys
– Different growth rates of body parts (e.g.,
limbs before torso)
– Association between early and delayed growth and behavioral/emotional problems
Sleep rhythms
– The need to sleep is delayed by ~2 hours (“sleep phase delay”)
– 9-hour sleep requirement
– Negative impact of cell phones/computers on sleep hygiene
Describe cognitive development of adolescence
PIAGET’S STAGES: Formal Operational Stage
12 years-adult
- Ability to use abstract thought, consider theories, devise hypotheses, examine cause and effect
- Problem-solving, planning, multi-tasking
• Improved ability to inhibit inappropriate behaviors in
favor of goal-oriented behaviors
– Impulse control and delayed gratification
• Regression to concrete thinking and disinhibited behavior are common under stress or heightened emotions in adolescence
Describe social/emotional development in adolescence
• Formation of a self-identity and individuation
―Importance of peers and de-importance of parents
• Reward seeking and highly motivated by emotional incentives
―Peer approval
―Sensation seeking and novelty seeking
• High emotional reactivity
―Difficulty down-regulating emotional state
―Sharp increase in depression rate compared to
childhood
Emotional system matures earlier than prefrontal control system
• Control over emotions improves with maturation of prefrontal pathways (e.g., uncinate fasciculus) to amygdala (emotion center) and basal forebrain nucleus accumbens (reward processing
Summarize adolescent risk-taking and brain maturation
• Risk-taking is higher in adolescence than in childhood and adulthood (non- linear trend)
– Cold reasoning (logical, cause-effect relationships) develops linearly from childhood to adulthood (prefrontal regions)
– Hot reasoning peaks in adolescence (limbic regions)
• Decision-making worsens in high- emotion contexts
What are the types of decision making?
Risk-taking involves decision making based on emotional (hot) reasoning and cognitive (cold) reasoning
― Example Decision Making: Should I drive my scooter without a helmet
Pros:(hot reasoning) (emotional)
- It will be more exciting
• I won’t get ridiculed by my
friends
• I won’t have to carry it around all day
Cons: (cold reasoning)(cognitive)
I could get in an accident and become physically injured, brain injured, or die
What are the special challenges to adolescent health?
- Weight
- Early Sexual Activity
- Mental Health Concerns – Depression
- Drug Use
- Violence
- Risk-Taking
How does weight change in adolescent health?
- Weight
―~15.5% of U.S. high school students are obese based on body mass index (BMI)
―BMI (children and adolescents)
• BMI (kg/m2) is converted to a percentile rank based on age and gender
th
• Obese: BMI ≥95 percentile
―BMI (adults)
• Based on absolute value of BMI
• Obese: BMI ≥30
How does early sexual activity change in adolescence?
EarlySexualActivity
– ~27% of US high school students are sexually active
• Linear decrease in sexual intercourse (1991-2019)
• 9% have had ≥4 sexual partners
– Sexually transmitted infections (STI)
• Human Papillomavirus (HPV)
▪ HPV most common STI in the US
▪ # of sexual partners is risk factor
▪ Increased risk of genital/anal warts and cervical cancer
– Teen Pregnancy
• Rate in U.S. is declining (18.8 per 1000), but still high
worldwide
Describe the mental health concerns of adolescent health
― Depressive symptoms in almost 1/3 of US high school students
― Strong female bias
What are the drug use concerns of adolescent health?
DrugUse
– Decline in current use of tobacco, alcohol, and marijuana
– Decline in having a history of drug use (“ever used”)
– Apparent increase in prescription narcotic misuse
Describe violence and risk taking acts
Violence
―Includes physical fights, threats of/or injury with a weapon, (cyber)bullying; sexual dating violence
- Risk-taking
– Sense of invulnerability contributes to excessive risk-taking (e.g., reckless driving, not using contraceptives)
What are the adolescent mortality in the US?
Top three leading causes of death (ages 15-19): 1. Accidents (unintentional injuries) – Motor Vehicle Accidents 2. Suicide 3. Homicide
What are the predominant health issues in childhood ?
• Top 5 causes of death vary by age
• Themes – Unintentional injuries (MVA, drowning) – Congenital abnormalities – Malignant neoplasms – HeartDisease – Suicide – Homicide
– Unintentional injuries • Relates to increased motor ability and physical activity – Exposure to communicable diseases • Upon the age of school entry
– Chronic medical conditions
• Asthma, diabetes
– Neurodevelopmental disorders
• Learning disorders, attention-deficit, and behavioral disorders
– Maltreatment/abuse
• Overuse of punishment in response to negativistic behavior
What is the correlations of poverty and pediatric health?
One in 5 children in the US lives in poverty (one in 4 minority children)
• Powerful predictor of health status for young children - POVERTY (i.e., an underlying cause of preventable illness
US National Institute of Health MRI Study of Normal Brain Development: Children from families with limited financial resources show:
– Reduced academic achievement test scores
– Reduced gray matter in the frontal lobe, temporal lobe,
and hippocampus
• Developmental differences in the frontal and temporal lobes may explain as much as 20% of achievement deficits in low-income children
➢This suggests that the influence of poverty on academic delays is partly mediated by delays in brain maturation
