motor development Flashcards
L 4/22
dynamic system theory - DST approach
modern approach used motor development and looks at how behaviour changes over time
emphasizes that multiple causes to different behaviour
e.g. being able to walk involves
increased in strength and weight, neural mechanisms, posture control, balance,perceptual skills and motivation
major milestones of motor development - birth to 5 months
stepping reflex
mini push up during tummy time
bounce when held upright
major milestones of motor development - 6 to 10 months
sit up
crawl
stand with support
cruise
major milestones of motor development - 9 to 15 months
pull to a stand
stand unsupported
take first steps
major milestones of motor development - 16 to 18 months
dance
climb stairs with help
walk backward
adolph et al 2008
motor skills do not suddenly turn on and data collected may not be consistent
this study showed graphs of infants ability to stand independently for 3 secs
showed daily and monthly measures
monthly measurement was a simple looking graph that showed that they weren’t able to then they were
where as the daily measurement showed days before the recorded month measure that some days they could and some days they could and then after they could consistently stand
fine motor skills
grasping
object manipulation
drawing
involve smaller muscles
(gonsales et al 2019)
gross motor skills
sitting
reaching
crawling
walking
running
involve large muscles
(gonsales et al 2019)
stepping reflex
(spencer et al 2006)
coordinated behaviour that resembles walking
alternating leg movements
disappears around 2 mo of age
why does the step reflex disappears ?
rapid weight gain causes legs to get heavier faster than they get stronger
DST demonstration (link to the reading) - make babies behave like other babies:
oldier babies in water
yonder babies with ankle weights
shown that it is not just neurological maturity because they can do the same behaviour when laying down
sitting independently
- no support from arms aids reaching (spencer et al 2000)
- sitting independently has a cascading effect on infants perception (ross-sheehy et al 2016)
- sitting creates new opportunities for exploring
- new opportunities for exploring shape visual perception
figure ground assignment
allows us to identify objects from the background
it helps us understand depth and plan reaching
adults use symmetry convexity lower region to determine figure ground
infants need to figure ground segregation to guide attention eye movement and learning
- ross sheehly et al 2016
ross sheehly 2016- figure ground assignment methods
a consistent and inconsistent video example - based on symmetry
showing that the background is what we would picture or not -stretch
two cues to figure:motion and symmetry
both screens had motion (both in front or both behind) difference in symmetry
ross sheehly 2016 findings
when children were capable of sitting they were better at telling the difference between the consistent items and inconsistent items
“a significant preference indicates sitting infants perceive symmetry as a cue to figure ground assignment”
rohr et al 2021 - reaching and grasping
stretching out one or both hands towards something to touch or grasp at it
initial reaches are swiping movements
reaching becomes stable after independent sitting
with increased experience.
more signs of anticipation in grasping - match hands to size of object
soft assembly
the idea that you have a lot of components are coming together in a moment - they are assembling in different ways
example of elements for grasping
locate the goal object
stable base
controlled arm extension
variable timing: need all components to assemble into a successful reach
sticky mittens
are a technique to help prevent flailing and assist teaching the child grabbing and reaching movements
have velcro that help children who are not yet reaching make contact with objects
(babies mitten have soft side and object have hook side)
libertus and needham 2010
sticky mittens
10mins a day for 2 weeks - one for training
after 1 week the infants in the training group (mittens) grasps and reached significantly more often than their peers
effects persists for 12 month
but see williams, gorbetta and Guam 2015 - non-sticky mittens had higher performance
Piaget - A, not B task
piaget thought that babies thought that something didn’t exist once out of their vision
so created the A-not-B task to test 8 to 10 month infants representations
in this test there are 2 hiding places and label the side where an object is hidden a and the other b
then give to the child to find the object
repeat
by trail 7 normally you switch to hid the object behind b in front of them
found they will still reach for 1 - motor response that they have learnt not that they have forgot about it
DST account of A not B
- behaviour is the product of past history just previous past and present - nested timescales
- A not B error is the result of previous attention to A and practice reaching to A
- DST explanation includes attractors, motor memory and perservation
error persist if there is no reaching on A - there is no object, unmarked location
- there is long delay
if you change posture between trials errors are reduced as less reliant on motor memory - made to stand
can get adult to do it - predural memory
self locomotion
at around 8 months infants become capable of self-location
infants begin walking independently around 13 to 14 months (with a toddling gait)
gibson and locke 1960
visual cliff
after first learning to crawl babies will cross but after a couple of weeks will no longer cross the drop off
actually happens because of a development in deep perception not because of a fear of heights
can actually test fear of height with an actual drop to see if they will lower themselves down
( a level - mothers on other side looking worried or encouraging )
adolph 1997 - motor skills are context dependent
tracked infants in a weekly longitudinal study from early crawling to proficient walking
knowledge does not transfer from crawling to walking
67% of children plunged down all slopes but did become more cautious with experience
knowledge is context dependent
hen and adolph (2020 wiley) - the importance of falling
falling (error in balance and motor control) may help us understand the role of errors in early development
138 toddlers - 13 to 19mo - were observed in lab playroom
toddlers fell 563 times in this study
so fall way more often than we realise - as they normally just get up as it is so normal for them
results
- falling didn’t alter subsequent behaviour
-after a fall, infants returned to play in 1.84 seconds on average
- impact was mitigated by small body size and infants quick reactive behaviours e.g. bracing with hands
only 4% of the time did they get upset and caregivers were only concerned 8% of the time
walking experience didn’t impact infant or caregivers reaction
frequent and low impact errors encouraged further practice
road crossing - Dr.neal et al 2018
children 5 to 14 years have higher rates of pedestrian injuries than any other age group
road crossing - Oakley et al 2012
most child pedestrian injuries happen at mid block
road crossing - benner and yiannakoulias
shorten path to school often requires crossing mid-block
road crossing - O’Neal et al 2018
6 to 10yr children are much slower than older children and adults to enter a road and also enter roads with much smaller gaps in traffic
o’neal et al 2018 - road crossing simulation
3 screens with the visual cues of a real life situation
timed gaps between the fake cars
one ways street
children cross with a lot smaller gap than what adults perceive as safe
o’neal et al 2019 - road crossing with friends
- pairs of friends crossed a virtual road 30 times (half on left/right)
- a steam of traffic came from the left at 40kmh (25mph)
- traffic included random 2 to 5 sec gaps
- no instructions to cross together or alone
they could wait to cross as long as they wanted to
results of crossing roads with friends
adults vs 12 year olds
were more likely in general to cross if there was a bigger gap in the traffic
were more likely to cross in the small/ riskier gaps if they were with a friend rather than being alone
to compensate for short gaps they entered and crossed faster
when solo, the first of the pair to cross were more risky
in general 12 yr olds were more risky than adults
