study guide human development exam 2

6 behavioral states of an infant

• quiet/deep sleep

• active sleep

• quietly alert

• actively alert

• drowsy

• crying

which of the 6 behavioral states has REM sleep

active sleep

quiet/deep sleep

still, regular breathing, restorative state

active sleep

irregular breathing, body movement, rapid eye movement

quietly alert

calm, attentive state. best for learning

actively alert

active, moving, less focused

drowsy

transitional state between sleep and waking

crying

distress signaling

why is REM important for babies

critical for brain development and memory consolidation

PGO spikes and theta waves prime hippocampus for learning

what are the reflex pathway

SAME

sensory receptor

afferent neuron → spinal cord

motor neuron out

effector (muscle/gland)

what is the criteria for being a reflex

hardwired,

inborn, automatic,

unconsious,

unlearned

define a survival reflex

reflexes with a clear adaptive value that help with survival

examples of survival relfexes

• breathing

• eye blink

• pulpillary relfex

• rooting

• sucking

• swallowing

breathing

stimulus- CO2 levels trigger increase in breathing rate

eye blink

stimulus- flash light or air puff

response- blink

pupillary reflex

stimulus- light

response- pupil constricts

rooting

stimulus- touches cheek

response- infant turns head and opens mouth

sucking

stimulus- object in mouth

response- sucking motion

swallowing

stimulus- liquid in mouth

response- swallow

primitive reflex definition

reflexes that have no clear adaptive value, considered evolutionary remnants

primitive reflex examples

• moro

• babinski

• grasping

• swimming

• stepping

moro

(startle)

stimulus- loud noise or sudden movement

response- arms fling out then curl in

babinski

stimulus- stroke bottom of foot

response- toes fan out

grasping

stimulus- pressure in palm

response- fingers curl

swimming

stimulus- placed in water face down

response- swimming like movements

stepping

stimulus- held upright, feet touch surface

response- step like motions

what did myrtle mcgraw do

studied twins johnny and jimmy to show how experience and environment influence motor development (classic twin study)

what is the dynamic systems approach

motor development = interaction of genes + experience

infants are motivated by goals, constrained by body limits, actively building skills, using perception to fine-tune movements and continually improving perception + action

who is esther thelen

psycologist who developed the dynamic systems theory of motor development

shows motor skills emerge the interplay of biology, environment, and experience

what does the text say about babies on slanted walkways/handrails

babies adapt behavior to new surfaces : they learn to use handrails and adjust walking patterns to slopes (not automatic, must be learned)

how many falls do toddlers have

about 17 falls per hour of free play

roughly 100 falls per day

principles of growth

orthogenetic

cephalocaudal

proximodistal

orthogenetic

developement moves from global → specific (whole body → one arm → hand grasp)

cephalocaudal

head to tail ; infants lift head before trunk, sit before walking

proximodistal

center to periphery; trunk → arms → fingers

2-3 months

lefts head while on stomach

3-4 months

rolls over

4-6 months

unlar grasp

6-8 months

sits without support, stands holding onto something, crawling

1yr

walks holding on, pincer grasp (cheerios grasp)

14 months

walks well

16 months

scribbles with crayon

17-22 months

walks up steps

20-24 months

kicks ball forward

9 years

can use household tools (hammer, screwdriver)

is there such thing as “throwing like a girl”

Differences in throwing style are more about socialization/experience than innate ability

at birth

20 inches

7-7.5 lbs

2 years old

-50% of adult height

27-30 lbs

adolesences

girls growth spurt- 12 years

boys growth spurt- 13-14 years

brain at newborn

25% of adult brain

brain at 2 years

75% of adult brain

brain at 5 years

90% of adult brain

andrenarche

ages 6-8

adrenal glands ↑ androgen production

menarche 

first menstration 12-13y

semenarche

first ejaculation - 13y

androgens/testosterone

drive male changes (muscle, voice, hair).

estrogen/progesterone

drive female changes (breast, hips, menstrual cycle)

menopause 

ovarian hormone decline, end of fertility. no more periods - 50y

andropause

gradual testorone decline in men- 50+

sensation

detection of energy by receptors → neural signals (transduction)

Perception

interpreting sensations using top-down processing (experience, context)

habituation 

decreased response with repeated exposure.

dishabituation

preferential looking

babies look longer at what they can discriminate.

Visual accommodation

ability of lens to change shape; focus from far to near

absent at birth, matures 6–12 mo

visual acuity

sharpness of vision and the ability to discern fine details.

• Birth: 20/400

• 1 mo: 20/120

When can babies perceive a meaningful face?

Around 2–3 months, once scanning of interior features improves

baby face preferences 

top-heavy, contour, movement, complexity (fantz study) 

fantz experiment

Babies prefer

faces > patterns > plain stimuli

contour

edges help define figure- ground

common motion

at 4 months, helps infants group features as one object

size constancy 

perceive object as same size despite retinal changes 

2-3 months visual milestones

detect brightness changes (rods),

color (cones mature),

explore interior of figures

depth perception

campos

gibson & walk

campos

2 months

perceive depth but no fear

heart rate goes up

gibson & walk

conducted the visual cliff experiment to study depth perception in infants.

when do infants fear depth

6-7 months

what book did mothers read to their infants prenatally

cat in the hat

last 6 weeks

2-3 years old attention

18 mins of unsustained attention

4 years old attention

can ignore intermittent distractions not constant

6 year old attention

>1 hour, 

more systematic focus 

adolescence attention

3-4 hours

multitask

selective attention

focusing on one stimulus at a time, while ignoring others

improves with age but declines late adulthood

cross modal

integrating senses

matching sight and sound

sticky mittens 

a tool for infants that enhance grasping and improve fine motor skills by allowing them to practice holding objects.

experience grasping helps with reaching

what are sleeper effects

delayed consequences of an early experience that may not become apparent until later in development.

what problem put infants at risk for development problems

early deprivation (ex- cataracts) harm long term vision

what was associated with a better feeding outcome

infants with who can coordinate sucking, swallowing, and breathing rhythms

older adults had problems with what kind of vision

novel or complex visual information esp when it requires speed/filtering distractions 

what happens to thresholds with age

they increase, more stimulation is needed

presbyopia

stiffining of the lens, lens loses elasticity so it cant accomodate for near vision

u become far sighted

cataracts

lens protein pump. lens becomes cloudy/opaque → blurry vision, color distraction

glaucoma 

fluid pressure damages the optic nerve → loss of peripheral vision (tunnel)

AMD

degeneration of macula → loss of central vision

ptsosis

drooping eyelids, reduces visual feild

what about glare/ what is dark adaptation

older adults take much longer to adapt to low light after bright light → glare sensitivity increases

decibles 

sound intensity — >85 dB for long periods damages hearing

tinnitus

ringing/buzzing in ears : affects 30% of adults after 60

presbycusis

age related hearing loss — difficulty with high/low frequencies especially consonants like ( s, ch, z)

who is sue 2.0

she had anterograde amnesia