motor development Flashcards
what are reflexes?
innate fixed patterns of action that occur in response to a particular stimulation
when do newborn reflexes fade? if they don’t, what does this indicate?
most reflexes fade during the first months – persistence can suggest motor disorders
what are the 5 newborn reflexes?
feeding reflexes, grasping reflexes, babinski reflex, stepping reflex, moro reflex
what are the 2 feeding reflexes?
ROOTING – baby turns head and opens mouth if you stroke the cheek
o Disappears at around 3 weeks and replaced by voluntary head turning
SUCKING – sucks things put in the mouth – replaced at 4 months with voluntary sucking
explain the newborn grasping reflexes (2)
- Appears in foot and hand – evolutionary remnant, clinging onto mother the way primates do today
- Disappears around 4 months when it’s replaced with voluntary grasping
explain the newborn babinski reflex (2)
- When the bottom of the foot is stroked – toes fan out and curl and foot withdraws from stimulation
- Disappears around 8-12 months
- LT persistence – indicated neurological problems
explain the newborn stepping reflex (2)
- When held upright over a flat surface – rhythmic stepping movements
- Disappears around 2 months and returns later on
explain the newborn moro reflex (2)
- Startled baby throws arms out backwards and arches back before bringing their arms back together as if holding something evolutionary sense as it would help CG catch you if they dropped you
- Disappears around 6 months
- LT persistence might indicate neurological problems
how do reflexes develop with the development of the cortex (2)
- early, simple reflexes arise from the brain stem (medulla)
- more complex, coordinated reflexes result from the development of the cerebral cortex – esp the primary motor cortex
how do voluntary movements develop with the development of the cortex (2)
- with the development of primary motor cortex (the first area to develop and responsible for voluntary movement)
- begins with raising head (1 month), control of arms (3 months) and leg control last to develop
what is the dynamic systems approach?
dynamic systems approach – a theory which emphasises influence of many factors/processes which influence motor development
not only neural mechanisms developing but increases in strength, control, motivation etc influence motor development
how does the stepping reflex support the dynamic systems view?
ESTHER THELLEN RESEARCH
o Examined infant’s performance of stepping movements
o In one experiment, weights were attached to the ankles of infants who still had the stepping reflex, and the babies suddenly stopped stepping
o In the second study, infants who no longer showed the stepping reflex were found to do so when they were suspended waist-deep in a tank of water that supported their weight. – started stepping again
o Suggests that the changing ratio of leg weight to strength was influencing the presence of the stepping reflex
o Reflex was thought to disappear at about 2 months of age because of cortical maturation, but demonstrations that the reflex could be prolonged or elicited long after it was scheduled to disappear were inconsistent with this interpretation
o Rather, the reflex is also to do with the development of the child’s strength as well which influence motor development
state the sequence of motor development
lift head, lift chest, rolls over, sit without support, stand with support, walking with support, stand alone, walk alone
how do reaching movements develop over infancy? (2)
- For the first few months children are limited to prereaching movements – clumsy swiping movements
- Infants start successfully reaching objects around 3-4 months
how does manual dexterity develop over infancy? (3)
- around 7 months as infant gain ability to sit independently, their reaching becomes quite stable
- 9-10 months – infants’ grasping approach dictated by want they intend to do with the object (Claxton et al 2003)
- by one year old, infants show sophisticated manual dexterity
how does self-locomotion develop over infancy? (3)
- Around 8 months – infants become capable of self locomotion for the first time as they begin to crawl
- Learning to move independently involves integrating movement from many different parts of the
how might putting a baby to sleep on their back impact their motor development? (3)
- the campaign to get parents to put babies to sleep on their backs to reduce the risk of SIDS seems to make infants less likely to roll over on schedule
- it may be that the better view of the world from their backs results in less motivation to roll over
- it may also be that spending less time on their tummies causes arm strength to develop more slowly
how does perceptual and motor development relate to each other?
they learn about objects and their affordances by interacting with them e.g the dangers of a cliff, or knife
what does the ‘specificity of motor learning’ relate to?
skills used for certain motor skills, or objects and their affordances don’t always translate to other skills/objects e.g a child was shown to be a lot more weary of a cliff when crawling (as they have spent more time crawling) than when they were sitting on it
when do infants start walking usually?
infants begin walking at around 13-14 months
how does specificity of motor learning relate to walking? (research)
- Specificity of motor learning also relates to walking
- Karen Adolph and colleagues (Adolph et al., 1993) found that infants do not transfer learning from what they know about crawling down slopes to walking down them
when do scale errors begin to occur? what are they?
- Scale errors – usually made after they start walking. It’s when they try to treat a miniature replica object as if it was a much larger real one (DeLoache et al., 2004)
- e.g child trying to sit on a miniature chair as if it is a large one
what are the main 4 reasons psychologists suggest scale errors occur?
- Perhaps due to dissociation between dorsal/ventral visual processing streams – these 2 streams process visual information differently – one does ‘what’ something is and the other does the ‘where’ Visual information for planning an action not correctly integrated with the system for executing that action
- Centration systems (lecture 2) in children – focus on ‘what’ the object actually is rather than looking at visual information of its size
- Failure to inhibit an automatically afforded action? – cars are for driving, thus we drive it – we have the ability to suppress these responses
- Patients with medial frontal lobe damage ‘alien hand syndrome’/’utilisation behaviour’ – can’t suppress the automatic responses/expectations of what you should do with an object
wairiness of heights - what is the visual cliff paradigm?
o The visual cliff paradigm – table with apparent steep drop that is covered with a continuous transparent platform (glass) that supports the weight of an infant
o A high- contrast checked pattern (e.g red and white gingham) continues from the shallow side to the deep side of the ‘cliff
visual cliff paradigm: what has research found? (4)
- 1.5 month old infants perceived the difference in the depth but showed no fear of the deep side (heart rate stayed stable?)
- 14 month old infants wouldn’t cross the deep side of the cliff – they did perceive and understood the depth cue of relative size?
- Early crawlers avoided heights earlier – active crawling experience means they have more information about environment and have more awareness of heights
- it’s not always experience that increases this wariness – there’s also the feeding of information through the peripheral vision - Visual cliff research illustrates the interdependence of different domains of development (e.g vision/movement – both are used to understand the wariness of heights/understanding of the environment)
- social referencing - if mum smiled more likely to cross
what’s social referencing? how does it relate to learning?
Social referencing is also used as means to interpret ambiguous situations again
highlights that one domain of learning influencing development in other domains – it is not always merely neurological as once thought!!
