Motor Development Flashcards
Major milestones in motor development
Birth to 5 months - stepping reflex, mini push ups, bounce when held
6-10 months - sit up, crawl, stand with support, cruise
9-15 months - pull to stand, stand on own, first steps
16-18 months - dance, climb stairs, walk backwards
2 years - run, kick a ball, jump
Lots of variability but at about 2/3, should all be able to do the same thing
Cause of motor development
Used to think it was neurological maturity
Now take a dynamic systems approach
What is the dynamic systems theory
Believes motor development is due to multiple causes - strength, brain, balance, perceptual skills, posture, motivation
Theory explains how behaviour changes over time
Not when, but how
Everyone arrives, but different routes (experimentation, learning - variable routes)
Stepping reflex
Lifting one leg, then other, resembles walking
Disappears at 2 months due to rapid weight gain (4 times birth rate by age 1)
Evidence that weight gain prevents stepping reflex
Thelan - rapid weight gain prevents the reflex
Attach weights to infants ankle who still have reflex - stops stepping
No longer have reflex, so put in water to support weight, reflex reappears
Movement and neural basis remains but masked by leg weight to strength ratio
Reaching reflex
Infants limited to clumsy, swiping movements at the start but when they can sit, reaching is stable (this is the first time they choose what they are looking at). With experience, they show signs of anticipation (changing hand size to grab). Reaching is dependent by what you want to do with the object. Feet are easier to control than hands
Soft assembly of motor development
This refers to how it all comes together
Motor development is not a fixed sequence, variability is okay, even good!
There is variability in when components come online, need all components for success. Not genes/brain but interaction of baby and environment
How can you aid reaching?
Sticky mittens - Velcro attached to them that help children make contact with objects
Evidence: parents give infants sticky mittens for 10 mins a day for 2 weeks, after 1 week, infants reached significantly more
Length of effect - when came back 1 year later, still better at reaching
Self locomotion
8 months - crawling, capable of moving on their own for first time
12/13 months - walking, after experience, they get better at this
When does depth perception emerge?
After crawling, crawling teaches fear of heights, when crawling, vision improves so they understand depth
What are scale errors?
Toddlers sense of scale is so fragile that their desires override perceptions, leading to errors (making an action on a miniature replica)
Do infants transfer what they learn from crawling to walking?
Infants do not transfer what they learn. Adolph - Longitudinal study: followed infants from 1st week of crawling to walking, experienced crawlers became more cautious but knowledge didn’t generalise to walking - 10/15 walkers fell down the slopes, even though they were cautious crawlers. Knowledge of slops is context specific - perception emerges when actions are stable - crawlers can’t match their perceptual abilities to actions
What is a critical period for the brain?
Well defined window of opportunity, clear start and end, something needs to occur or development won’t happen
What is a sensitive period of the brain?
Period where neurosystem requires some impact or typical development won’t happen
Sensory deprivation studies
Hubel and Wiesel - monocular and binocular deprivation in cats. Nuerons respond to input from both eyes. they took kittens and denied input to one eye. found: even after restored input, neutrons only responded tonne eye, cortex didnt know what to do
The rationale of this was to help treat children with congenital cataracts, if not treated early, won’t have full vision
