Chapter 5 Motor Development

Question 1

What are reflexes?

Answer 1

Fixed patterns of action that occur in response to particular stimulation

Not goal-oriented

Question 2

What are some examples of newborn reflexes?

Answer 2

Eye blink
Withdrawal reflex
Rooting
Sucking
Palmar grasp
Stepping

Question 3

What impact does culture have on milestones in motor development?

Answer 3

It can impact when milestones are reached
Stretching and moving in African culture can lead to early development of milestones

Question 4

What is the dynamic systems perspective of motor development?

Answer 4

Each skill is a product of earlier skills

Cultural and idiosyncratic practices strongly influence the rate and timing of motor development and can shape specific motor skills, but they rarely alter the eventual attainment of basic species-typical motor abilities

Emphasizes learning with the body and environment

Question 5

The viewpoint of walking

Answer 5

The stepping reflex disappears around 2 months of age
Maturation of the central nervous system and the disappearance of the stepping reflex.

BUT how can it be cortical maturation that yields the disappearance if 8-week-old infants given extra practice with the reflex still show it

Ester Thelen
The stepping reflex is no longer visible, because the baby’s legs were getting larger and chubbier and becoming more difficult to do and for it to show

Question 6

What is the development of reaching?

Answer 6

Five months of age: hand shape and orientation match goals
Ten months of age: arm trajectory and speed match goal
Younger babies are not able to reach selectively and intentionally

Question 7

What are pre-reaching movements?

Answer 7

Clumsy swiping movements by young infants toward objects they see

Question 8

Sticky Mittens 1 Study

Answer 8

Procedures:
Velcro mittens in babies’ hands and velcro on the toys
Babies can swap for the toys, and it could grab the toy
16 pre-reaching infants given 10-minute sticky mitten sessions: 16 infants in the control group
Dependent measures: holding time, looking time, mouthing time of the objects

Results
Infants given enriched experience showed more sophisticated object exploration strategies and more object engagement

Question 9

Sticky Mittens 2 Study

Answer 9

Procedures:
3 months old tested
Half in active object play (with the velcro mittens) and half in passive object play
10 minutes per day over 2 weeks
Track eyes while babies view faces and toys on a computer

Findings
Active training, 3 months old look more like an untrained 5-month-old than the passive training 3-month-old
Preference for faces over objects
Given the experience, their visual scanning behavior looks more like that of older babies
Early motor experience affects orienting towards faces

Question 10

The Visual Cliff Study

Answer 10

Connects depth perception to motor development and social referencing
Plexiglass plate over the checkerboard pattern, but the checkerboard pattern makes it seem that there is a drop
6 months old would wiggle across
10 months old would not
The original conclusion was 10 months old, but not 6 months old had depth perception

BUT
When you place a 3-month-old over an apparent edge, there is evidence that they perceived depth (physiological events)
Seems to be not that depth perception is what’s changing, but the perception of fear is what’s changing
Social referencing influences (baby looking toward mother for feedback on the situation)
The probability of the likelihood of the baby crossing is influenced by the emotion displayed by the mother
If smiling and excited, the baby is more likely to cross the visual cliff
If anger or sadness emotion displayed, the baby is less likely to cross the visual cliff

Question 11

What is self-locomotion?

Answer 11

The ability to move oneself around in the environment

Question 12

Locomotor and Prelocomotor 7-month-old infants Study

Answer 12

Slowly lower infants to the deep or shallow side of the cliff
All infants show visual placing response on the shallow side and not the deep side: so all infants have depth perception
Only locomotor infants show heart rate acceleration over the deep side

Question 13

Accelerate locomotor experience Study

Answer 13

4 groups of infants (all the same age, around 7 months)
Prelocomotor infants given 47 hours of walker experience at home
Locomotor infants given 32 hours of walker experience at home
Prelocomotor control group given no walker experience
The locomotor control group gives no walker experience

Results
All infants given locomotor experience showed more heart rate acceleration than matched controls on the visual cliff
So the walker experience made prelocomotor infants wary
Walker’s experience for locomotor infants was a double-dose effect

Question 14

What roles do visual experience and self-directed action play in perceptual-motor development?

Answer 14

Possibility 1: visual and motor experiences do not need to be integrated - seeing the world around you (and later, moving in the dark) is enough to learn

Possibility 2: visual and motor experience need to be integrated; active (but not passive) motion needs to be combined with visual input to develop perceptual-motor skills

Question 15

Held and Hein (Animal study)

Answer 15

Procedure:
Contraception with kittens in it
On one side the kitten could walk and move the carousel and getting visual information
The passive kitten can’t walk but connected so when the active kitten walk so does the passive kitten, allowing for them to get visual input

Findings:
Only the active kitten responded normally
It avoided the visual cliff, showed fear of heights
It blinked in response to incoming stimuli
It lowered its feet toward and approaching surface (placing response)

Motor activity needs to be paired with visual input in order for typical visual-motor integration to occur

Question 16

What are the take home messages from visual cliff?

Answer 16

Depth perception in the visual cliff emerges early, before crawling

Locomotor experience, not age accounts for healthy fear of heights

Lack of fear is not due to perceptual deficits

Active, not passive, experience is important
Infants use emotional cues from parents (social referencing)

Question 17

What are affordances?

Answer 17

The possibilities for action offered, or afforded, by objects and situations

Infants discover affordances by figuring out the relations between their own bodies and abilities and the things around them.