Chapter 5 Flashcards
The brain
The source of all cognitive skills, emotional processing, personality and overt behavior
General structure of the nervous system
80 billion neurons. 80 billion glial cells
Neurons store and transmit information Dendrites receive Axons transmit Axons are myelinated, nodes of ranvier Myelin comes from oligodendrocytes Axons end in axon terminals with synapses
Synapses - gaps where neurons transmit between themselves
Pre and post synaptic neurons separated by the synaptic cleft
Neurotransmitters cross them
Adrenaline
fight or flight
Noradrenalin
concentration
Dopamine
pleasure
Seratonin
mood
GABA
calming
acetylcholine
learning
glutamate
memory
Endorphins
Euphoria
Frontal lobe
Motor Control (premotor cortex) Problem solving (prefrontal area) Speech production (brocas area)
Temporal Lobe
Auditory processing
Language comprehension (Wernikes area)
Memory/information retrieval
Brainstem
Involuntary responses
Cerebellum
Balance and coordination
Occipital lobe
Sight
Visual reception and visual interpretation
Parietal lobe
Touch perception (somatosensory cortex) Body orientation and sensory discrimination
Electroencephalogram (EEG)
fast
Very safe
Is a baseline level of activity
there is an event
measure the event related potential (ERP)
EEG is time locked to stimulus
Measures alpha, beta, theta and gamma waves
Measures local field potential of many neurons
Goes to amplifier
Then to data acquisition computer
WEAKNESS - POOR SPATIAL RESOLUTION
CAT
Computerized Axial Tomography
X ray slices
Put together by PC
Low resolution, enough to diagnose major abnormalities.
MRI
Structural imaging
High spacial resolution
PET
Positron emission tomography Radioactive oxygen in blood see flow positrons collide with tissue and emit gamma rays image of cerebral blood flow FUNCTIONAL IMAGING
fMRI
different responses of oxy/deoxy heam
changes in blood flow measured as a surrogate for activity
Activity and structural images
Early brain development
3rd week of embryonic development - outer layer thickens and forms neural plate
Folds to form neural groove
between week 3 and 4 this fuses and forms the neural tube which will be brain and spine
3 bulges emerge, these are the primary vesicles
Prosencephalon
cerebrum
Mesencephalon
midbrain
rhomenephalon
brian stem and spinal chord
Prosencephalon differentiation
telencephalon
diencephalon
telencephalon differentiation
cerebral hemispheres - grows faster relative to other parts
diencephalon differentiation
Thalamus and hypothalamus
mesencephalon differentiation
midbrain (no sub division)
rhomencephalon differentiation
Methencephalon pons and cerebellum
mylencephalon medulla
Methencephalon
pons and cerebellum
mylencephalon
medulla
By 11 weeks
resembles brain. telencephalon grows faster
Will develop after birth but is similar to fully developed brain
Prefrontal cortex
consciousness
inhibition of impulses (regulates inappropriate responding at about 1 year old and increases control through school age years.
Use of memory and reasoning/planning
Little activity in 5 day old babies
Increases by 111 weeks
Near adult levels 7-8 months after birth
Lateralizaion of the cerebral cortex
Right
Spacial
Negative emotion
Holistic, integrative processing
Left
Verbal abilities
Positive emotion
Sequential, analytic processing
Prefrontal cortex and emotions
Left - emotions stem from tendency to approach
Right- avoid
Kids physical growth basics
Boys get half their adult height by 2 and girls 18 months
CEPHALOCAUDAL PRINCIPLE - humans heads grow first, limbs catch up later
By 4, kids with obesity risk in adult life show this
Secular growth trends
changes to development between generations due to environmental factors
Genetic growth
identical twins 0.9
fraternal 0.7
Average of parents height 0.5
Hormones
HGH needed for growth
Dwarfism is treated with HGH
Nutrition
Really important
at 2 months old 40% of calories goes to growth
Babies need 100-200 kcals per kg
Dont give too much carbs
Breastfeed in areas where water is toxic
Picky eating by 2 year olds is adaptive cos they dont eat new things so things they eat are safe.
Breastmilk is best
Malnutrition
drops iq and concentration
Accidents are the biggest killer over 1 year old
Brain growth
Production of neurons begins at 10 weeks
By 28 weeks has all neurons it will have (nearly)
Built in stages, going outward
In 4th month of life, mylenation starts
Sensory gets this first, motor after
This is why kids get more coordinated with age (part of reason)
Motor skill development
Fine and gross
How do they develop?
Which one is first?
2 parts. First is
(a) fine motor skills
Self help, dressing eating
Drawing
Fine motor skills develop through daily routine
(b) Gross motor skills Walking, running Balance improves Gait Upper and lower body combine better Greater speed and endurance Develop through play
Grip newborn
pre reaching
Grip 3-4 months
ulnar grip
Grip 4-5 months
Transfer object from hand to hand
Grip 9 months
pincer grip
Biggest achievement
used for everything (eg writing)
Infant reflexes basics
Reflexes are unlearned responses to a specific stimuli
Infants reflexes show if neurology works or not
It is also a problem if they are there too long
Babinski reflex
Sole of foot stroked
Fans out toes and twists foot in
Ends at 9 months to a year
Blinking reflex
Flash of light or puff of air
Closes eyes
Permanent
Grasping reflex
Palms touched
Grasps hard
Weakens at 3 months, goes away at one year
Moro reflex
Sudden move/loud noise
Throws out arms and legs and pulls them back to body
Goes at 3-4 months
Rooting reflex
Cheek stroked or side of mouth touched
Turns to source, opens mouth, sucks
3-4 months
Sucking reflex
Mouth touched by object
Sucks
3-4 months
Swimming reflex
Put in water face down
Swims
6-7 months
Tonic Neck reflex
Placed on back
Makes fists and turns to right
2 months
The functions of infant reflexes
Get nutrients - rooting and sucking
Avoid bad stimulation
Blink and withdrawal
Prepare for voluntary motion
Walking reflex
Stepping reflex
Held with feet on floor
Walks
Milestone in motor dev: 0 months
Fetal position
Milestone in motor dev: 1 month
Chin up
Milestone in motor dev: 2 months
Chest up
Milestone in motor dev: 3 months
Reach and miss
Milestone in motor dev: 4 months
Sit up with support
Milestone in motor dev: 5 months
Sit on lap, grasp object
Milestone in motor dev: 6-7 months
Sit alone
Milestone in motor dev: 7-8 months
Stand with help
Crawl
Milestone in motor dev: 8 months
Pull to stand by furniture
Milestone in motor dev: 11 months
Stand alone
Milestone in motor dev: 12 months
Walk alone
Dynamic Systems Theory
Motor development involves many distinct skills, organised and reorganized.
CNS development
Body movement capacity
Goals
Environment supports skills
Eg walking requires balancing, moving limbs, perception of environment, want to move
Baby walkers
Illegal in canada
Food
at 5 months can handle finger foods
1 year olds use a spoon by lowering it into a thing
2 - use scooping method
Handedness
When young use both
By 13 months have a preferred hand which becomes more preferred with time
Hereditary - lefties often have lefty parent or grandparent
XP - world is built for right handed people
Cultural variation of motor development
Rates are affected by
early movement opportunities
environmental stimulation
child rearing practices
in pygmy tribe, babies cut trees
Large gene component (maturation)
XP speeds this up
Sense of smell
Babies smell develops in the womb
sweet stuff=relaxed
ammonia=grimace and turn away
Babies like the smell of the food their mothers ate when pregnant
Sense of taste
Babies have a sweet tooth
can differentiate between salty, sour, bitter and sweet
Like sweet, grimace with sour
Infants nurse more when mother has consumed sweet stuff before feeding (boob milk is sweet)
Sense of hearing
Hear well though not as accurate as adults
Can hear 7 months into gestation
Know their names at 4.5 months of age
Can differentiate between far and near
By 6 months can respond to most sounds but not fully developed until 30 months
EXPERIMENT
Mother and experimenter wear noise cancelling headphones
Dont know what sound or frequency
Babies look to or pay more attention to a sound from a direction
Or of they prefer one sound over another, more attention
Sense of sight
other 3 developed in womb
sight - no color vision until 3 months - cone cells take that long to develop. 3-4 months is like adults
Takes a while to develop because its complex and there is no stimulation in the womb
Newborns and one year olds see at 6 m what adults see at 60-120
EXPERIMENT
Grids and babies paying attention to novel things
Integrating sensory info
Kids integrate stuff
Recognize visually an object they just touched before
Can dance
Perception of objects
use continuity of
color
texture
aligned edges
if it turns out to be two objects babies are surprised
Perception of movement
if two parts of a pencil move together, its one pencil
Shape constancy
babies have a concept of this
Dont look at new thing longer when its not a new thing but an old thing from a different angle
Babies love faces
before 3 months all face
after 33 months features of faces
over 3 months likes objects which have correct facial configuration
Retinal disparity
by 4-6 month they use this
Depth with pictorial cues
Texture gradient course but distinct = close, smooth = far
Interposition - one in front of other
Linear perspective
Relative size
Visual cliff experiement
Don`t want to cross cliff
baby can see its different (slower heartbeat)
When start crawling or walking, drop off it
after some weeks, avoid or navigate it
Not a result of fear, a result of learning to perceive the relations between their bodies and the world
Pain
Bodies can transmit pain signal
Is stressful to babies
Useful to signal to caregivers when there is danger
