Infancy and brain development

What senses are well developed at birth? How do we know they are well developed at birth?

taste- sucking when sweet

smell - babies response to disgust

hearing - preffered mothers voice in womb

what sense are not very well developed at birth?

vision

In the study where mothers 7-9 months pregnant, read 1-3 stories twice a day, what did they find?

babies who heard stories in the womb - changed their sucking to hear familiar story

babies who didnt hear stories in the womb - didn’t chnage their sucking

In the study where babies suck their dummy whislt their mother or another woman read dr suess, what did they find?

• recognised their mothersvoice

• all babies except one preffered their mothers voice

at what distance do babies best recognise objects?

30cm away

at what age is vision acuity adult like?

6-8 months

Describe babies colour perception at these ages:

1 month

2 month

4 month

1 = red and green cones in place

2 = colour discrimination

4 = categorical colour perception

at what age do infants use msot cues by?

6-7 months

Describe a babies physical ability at these ages:

1-3 months

3-4 months

7-8 months

1 year

1-3 = arm moves in direction of object, hand closes before reachign object, swipes at object

3-4 = arm moves toward objects, graps object, brings to mouth

7-8 = crawling

1 = walking

Describe chimp brain weight

• at birth, weight is 40% of adult brain weight

• reaches 70% of adult brain weight in one year

describe infant brain weight

• at birth, weight is 28% of adult brain weight

• reaches 70% of adult brain weight at 3 years

• 90% of adult brain weight in 6 years

do number of neurons increase or decrease?

neither, it is fixed - they grwo bigger and strengthen

what is synaptogeneis

the forming of synpases

glial cells outnumber neurons what?

9 to 1

what is the function of glial cells?

they supply nutrients and oxygen to neurons and , form myelin and remove dead neurons

At what age is synaptic density most efficient?

14

What affects synaptic density?

experiences

what are the 3 examples of how experience affects brain development

1. correction for strabismus msut be corrected before age 6, primed learnign changes at this age

2. phoneme perception - baby sounds are the same for 6 month old regardless of language (perceptual narrowing)

3. emotional closeness (children and depressed mothers) - stress increases cortisol levels and interferes with neural development.

where does the least amount of synaptic changes occur?

brainstem

where does the most amount of synaptic changes occur?

cerebral cortex

in terms of synaptic development, what happens at these ages

2 years

3 years

2 - number of synapses reaches adult level

3 - childs brain has twice as many synapses as adult

how many synapses are eliminated every second in cerebral cortex?

33

Describe the romanian orphanages, what did the PET scan show?

• banned contraception and abortion

• led to unwanted children

• these children were neglected, physically and sexually abused

• given drugs to control behaviour

PET = brain didn’t develop if deprived of a good childhood

within the first year of infancy, what develops?

motor cortex, visual cortex and hippocampus

when does the frontal cortex develop?

not until late adolescence or early adulthood.

what is the function of myelination?

speeds transmission of info in the brain

what is multiple sclerosis?

the breakdown of myelin - paralysis, loss of sensation, memory issues and speech issues

glucose is improtant for what?

learning

describe what glucose does at these ages

5 weeks

8 months- year

2 years

9 years

18-20 years

5 - glucose is highest in sensorimotor cortex, thalamus, brainstemm, cerebellum

8-1yr - rate of glucose picks up in cortex

2 - rate continues to age 9

9 - glucose metabolic rate declines - reflects pruning

18-20 - reaches adult values

at what age does pruning of glucose stop?

18-20 years

what 3 thinsg are msot improtant for brain development?

nourishment, care, surroundings

brain develops until what age?

22-25 years

what are the 3 areas in the brain of greatest development?

PFC, corpus callosum and cerebellum

What 7 things are essential for optimising brain development?

• some risk taking behaviours

• surrouding them with language

• reduce screens

• encourage play

• respond to childs cues

• caring relationship

• good health, safety and nutrition

how much does the brain weigh?

1.3kg

at what age do girls reach puberty and how much earlier than boys?

10-11 years

and 2-3 years earlier than boys