Human Development II

Question 1

What are the trends in Brain Development?

Answer 1

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

Question 2

What’s the significance of synaptic density?

Answer 2

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

Question 3

What’s the significance of myelination?

Answer 3

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)

Question 4

What are the features of physical development in early childhood?

Answer 4

• 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)

Question 5

Summarize the pre-operational (Pre-logical)of Piaget stages

Answer 5

2-7 years

Representations – objects represented by words or images
• Ability to pretend

• Egocentric thought processes predominate
– Difficulty taking other’s perspectives

Question 6

What is the pre-operational stage?

Answer 6

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)

Question 7

What are the features of cognitive development in early childhood?

Answer 7

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

Question 8

Describe emotional development in early childhood

Answer 8

• 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)

Question 9

What are the social development features of the early childhood?

Answer 9

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

Question 10

Describe physical development in middle childhood?

Answer 10

• 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

Question 11

Describe the cognitive development of middle childhood

Answer 11

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

Question 12

Summarize cognitive development of middle childhood

Answer 12

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)

Question 13

Describe emotional development in middle childhood

Answer 13

• 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)

Question 14

Describe social development in middle childhood

Answer 14

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

Question 15

Explain physical development in adolescence

Answer 15

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

Question 16

Describe cognitive development of adolescence

Answer 16

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

Question 17

Describe social/emotional development in adolescence

Answer 17

• 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

Question 18

Summarize adolescent risk-taking and brain maturation

Answer 18

• 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

Question 19

What are the types of decision making?

Answer 19

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

Question 20

What are the special challenges to adolescent health?

Answer 20

1. Weight
2. Early Sexual Activity
3. Mental Health Concerns – Depression
4. Drug Use
5. Violence
6. Risk-Taking

Question 21

How does weight change in adolescent health?

Answer 21

1. 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

Question 22

How does early sexual activity change in adolescence?

Answer 22

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

Question 23

Describe the mental health concerns of adolescent health

Answer 23

― Depressive symptoms in almost 1/3 of US high school students
― Strong female bias

Question 24

What are the drug use concerns of adolescent health?

Answer 24

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

Question 25

Describe violence and risk taking acts

Answer 25

Violence ―Includes physical fights, threats of/or injury with a weapon, (cyber)bullying; sexual dating violence 6. Risk-taking – Sense of invulnerability contributes to excessive risk-taking (e.g., reckless driving, not using contraceptives)

Question 26

What are the adolescent mortality in the US?

Answer 26

``` Top three leading causes of death (ages 15-19): 1. Accidents (unintentional injuries) – Motor Vehicle Accidents 2. Suicide 3. Homicide ```

Question 27

What are the predominant health issues in childhood ?

Answer 27

• 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

Question 28

What is the correlations of poverty and pediatric health?

Answer 28

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