Motor Development

Question 1

What are the two types of movement?

Answer 1

• Reflexes
• Voluntary movements

Question 2

Voluntary movements

Answer 2

Purposeful.

Initiated entirely within the central nervous system.

Performance improves with practice

Question 3

Reflexes

Answer 3

These are fixed, automatic, triggered in response to a specific sensory.

Question 4

Patellar Reflex

Answer 4

The sudden move of the leg when a light tap hits the knee.

Question 5

Reflexes in Newborns

Answer 5

• Rooting reflex
• Grasp reflex
• stepping reflex
• Moro reflex

Question 6

Rooting reflex

Answer 6

When brushed on the cheek, babies will move their mouth towards it.

Question 7

Grasp reflex

Answer 7

Babies grab on anything on their hand

Question 8

Stepping reflex

Answer 8

Babies make the motion of walking when they are lowered on a surface

Question 9

Moro reflex

Answer 9

Arms move to the side when they are not supported.

Question 10

Many of the reflexes that the newborns have will disappear in the first few months of life, why?

Question 11

What are the two theories of Motor Development?

Answer 11

1. Maturational Theory
2. Dynamic Systems Theory

Question 12

Maturational Theory

Answer 12

This theory says that motor development depends entirely on the development of the cortex. As the cortex develops, it begins to override these early reflexes.

Question 13

What supports the maturation theory?

Answer 13

1. Practice has little effect on the age at which children begin walking

• Experiment by Gesell and Thompson (1929)
  
  • This experiment was made with twins in which ne of them got daily practice and the other didn’t
  • No difference in skills between the practice baby and their sibling after 52 weeks.
• Dennis and Dennis (1940)
  
  • Hopi people carry their babies swaddled (have less mobility)
  • Reduced motor experience didn’t affect onset of walking.

NOTICE extreme deprivation may result in motor delays but they can be reversed

Question 14

What challenges the maturity theory?

Answer 14

Some research suggests that experience does affect motor development:

• Restrictive parenting may delay the onset of walking
• Back to Sleep campaign
• Esther Thelan research

Question 15

Motor development timeline

Answer 15

• 2-3 weeks can lift chin
• 5-10 weeks can lift chin and take their head off the floor
• 3 months can hold-steady, roll over
• 6-7 months sit up
• 8 months no more stepping reflex
• 8-10 months crawl
• 9 months cruising
• 12-14 months walking

Question 16

What does it mean when we have a U-shaped Developmental Trajectories?

Answer 16

This indicated that a child is figuring out a new way of doing something.

Question 17

Why does stepping stop?

Answer 17

Notice that when the baby is laying on their back, they still make this motion. This is because it is easier to do it! This stops when the baby becomes heavier!

NOTICE This is inconsistent with maturation theory

Question 18

Stepping reflex stops with weight: Study 1

Answer 18

Thelen, Fisher and Ridley-Johnson (1984)

• Tested on 2, 4 and 6 weeks old!
• The babies were powered on a surfaced and the number of steps they made was counted and arousal levels
• They also got detailed measured of their bodies

Results: (slide 20, w2e2)

• number of steps decreases with age and arousal level predicted number of steps
• Infants gained weight rapidly between 2 and 4
• correlation between weight increase and stepping decrease

Question 19

Stepping reflex stops with weight: Study 2

Answer 19

Thelen, Fisher and Johnson (1984)

• 12 4-weeks-old
• Their legs were strapped to some small weight
• They were made to step with and without weights

Results: (slide 22 w2e2)

• More steps without the weight
• No arousal difference

Question 20

Stepping reflex stops with weight: Study 3

Answer 20

Same principle as the two others but with babies in the water.

Babies stepped more in the water (as it is lighter)

Question 21

Dynamic Systems Theory

Answer 21

Development of complex behaviour must be understood in terms of the interactions between all of the components involved in executing that action.

Movement:

• Physical properties of the body
• Perception
• Navigating an environment
• What is the context for and the goal of the movement

Question 22

Voluntary Movements

Answer 22

Newborns can’t move much, they can move their head if it is held properly.

Question 23

Variability in Motor Milestones

Answer 23

• The order of motor development is not universal. Some infants skip stages and often they are engaged in multiple skills at the same time.
• Infants are continuously discovering new ways to get around but they don’t immediately stop the old ways

Question 24

What babies learn at one locomotor stage may not transfer to another. Give examples that support this.

Answer 24

The Visual Cliff

This was made to test if the infants would see the cliff ad go over it. In this experiment, the table had a glass that made it seem like there was a cliff.

Results:

7-8 months old: 33% of new crawlers avoided the cliff where 65% of experienced crawlers avoided the cliff.

Karen Adolph

An experiment where babies were faced with a gap. If they were crawling and were experienced crawlers, they would avoid the gap when it was too big but if they were walking (not experienced walkers) they would attempt to continue. This also happened when sitting and crawling situations.

(w2e3 slide 14 to 24)

Question 25

What does it mean to have successful locomotion?

Answer 25

This means that they can adapt to novel situations.

• Need to be able to develop adaptive solutions
• Even when babies are walking comfortably there will be circumstances in which they can’t do it
• Need experience in a posture to be able to do this.

Question 26

Learning to Walk

Answer 26

On a study by Adolph et al. 2012, they measured the distance, the number of steps and the number of falls for babies that were learning to walk.

They noticed that as the walking ages increased, the distance and number of steps increased and the number of falls dicreased.

Question 27

How do caregivers help children with motor action?

Answer 27

• Caregivers give motivation and security.
  
  • calling the baby to you while the other parent helps them
• They also give motor experience
• They provide information such as warnings

Question 28

Social Reference in Motor Development

Answer 28

• Infants often look at adults to guide their behaviour.
• Social referencing: Look at the emotions of adults to determine their own actions.
• Based on the caregiver’s expression babies would avoid or approach novel tasks, objects and people.
• In a study by Tamis-Lemonda et al. (2008)
  
  • babies were put in different situations with different slopes.
  • Most often, if the slope was feasible, the babies would not consider the caregiver’s emotions
  • If the slope was clearly difficult they would avoid it
  • If it was not clear, babies would tend to listen more to the caregiver.

Question 29

True or False

Locomotion affects other domains

Answer 29

Yes, this is due to the fact that the baby’s perception changes. They are also able to interact more with their environment. For example, what they see while crawling is different than what they see when walking. They are also able to grab things when they are walking instead of crawling.

Walking allows babies to interact more with adults and to point to objects. This helps them improve their social interactions and language.

(Slides W2E4 4,5,6)