human development chapter 4

cerebral cortex

the “new brain” contains lobes and cortexes

• 80% of volume

central core

• old brain

• brainstem and cerebellum (primative brain structure)

laterization

• separation between right and left hemisphere and their functions

• connected through corpus callosum

Hand model of the brain (Daniel Siegel)

• flipped lid

• thumb = amygdala/ limbic region (emotion)

• fingers = prefrontal cortex (critical thinking)

• knuckles = cerebral cortex

toxic stress

• sensitization of stress (increased)

• reduces neural connection in important critical parts of brain (hippocampus and prefrontal lobe)

• stress that is chronic

• caused when infants in critical period do not have the (parental) support they need in order to regulate stress

ACE realms (3)

adverse childhood experiences

1. household

2. community

3. environment

brain plasticity

brain’s ability to change neurologically because of environment and in response to experiences

• experience/ enviro affects biology

• “use it or lose it” “neurons that fire together wire together"

• loss of unused neural connections

• more and thicker neurons form when growing up in safe enviro

neurotransmitters

binds onto dendrites of neurons via synapses

• “lock and key” mechanism - either locks to excite or locks to prevent

  • excitatory or inhibitory

experience-expectant brain development

things our brain needs to be exposed to in order to process info

• light, sounds, language

experience-dependant brain development

growth from learning and experiences

• toy as a kid, a specific language

synaptogenesis

creation of new synapses

(dendrites grow and branch out)

transient exuberance

when first born we create way more connections than needed

• temporary excitement of brain in creating connections

synaptic pruning

brain gets rid of unused neural connections and the way too many infants made

serve and return

essential for development of brain architecture

the responses of babies actions that helps them when they have good support

• lacking when neglected

neglect’s negative impact

• fails to provide stimuli (no serve and return)

• AND creates chronic stress response (toxic stress)

6 newborn reflexes

1. moro

2. palmar

3. rooting (turns head towards cheek touched)

4. sucking

5. babinski (fans toes)

6. stepping/walking

fine motor development

small movements

gross motor development

ability to control large movement

dynamic systems theory

things develop systematically and build on each other

→ maturation (biological, cognitive and psychosocial ←→ contextual supports and challenges ←→ goals and understanding ←→

• ex: kid being able to walk is result of several processes (infants desire to explore world, physical capacities, environmental support, central nervou system)

affordances

the nature, opportunity and limits of objects

• tell infants weather an object is squeezable, catchable or reachable

• searching environment systematically to discover the properties of things around them

• grows as we develop

• ex: a pot has a dif purpose to infant vs 12 year old

cognitive reserve

brain’s ability to make efficient use of available brain resources

• type of plasticity made throughout life from experiences and environmental factors

(adults’ brains compensate for age related losses)

Gibson perception study

babies can perceive depth

environment provides all the info we need

• avoidance of cliff’s edge increases as babies go from crawling to walking

depth perception: 6-7 months

hearing in infants/ newborns

• most pronounced and developed sense at birth

• after 3 days they can turn towards sound

• perfer human voices

touch for newborns

• mouth is first to show sensitivity

• need skin to skin

smell and taste for newborns

• preferences are well developed at birth

• can be influenced by what mother ate

• can tell their mothers scent

how do adults brains change?

• age related losses (compensated by cognitive reserve)

• increased plasticity: pregnancy, physical activity

nun study - what is it and what does it show us about brain development?

• study nuns who have many less variables in their lives (same routine, no family, no kids…)

  • allowed to conduct aging research related to alzheimer’s

• idea density - lower means higher risk of developing alzheimer’s

• proves: early life linguistic abilities and lifestyle habits influence late life brain resilience

adolescence

• brain continues to develop

• volume changes: cerebral cortex increaes about 1% each year

• pruning: accelerated rate during adolescence

  • prefrontal cortex gets bigger during adolescence

• limbic system

  • burst of development (before prefrontal cortex)

• Gray and white matter

  • gray matter (cell body and dendrites) decreases

  • white matter (axon) increases

Daniel Sigel/ myths of adolescence

• seen as a nuisance instead of a vital developmental transition

• “raging hormones”/ “just need to grow up” / “Dangerous impulsivity”

remodeling:

1. increase in cerebral cortex (second synaptogenesis)

2. difference in timing of synaptogenesis

3. dopamine baseline is lower

What affects young children’s flavor preferences? What is the sensitive period for flavor preferences?

what they’re exposed to as infants and even what their mom was eating

• children prefer breast milk to formula

• sensitive period: (4-18 months) starts even before birth

• another anesthetic

persistence of exposure

• 8 or more exposures to change familiarity

vision in infants

least developed at birth

2 months: focus and color

6 months: acuity, scanning and tracking

6-7 months: depth perception

8 months: close to adults

prefer to look at human faces