Early Motor Development

Question 1

What is the role of cognitive development on the development of movement? (how infants move: first thing to consider)

Answer 1

recall the maturational perspective on development: brainstem/spinal cord - primitive reflexes
mid-brain:righting reactions
cerebral cortex:equilibrium reactions

Question 2

as the brain develops, the maturational perspective suggests that the CNS was _

Answer 2

the sole constraint to guide early motor behaviour
- imlries unindirectional control

Question 3

is the maturational perspective correct about the CNS being the sole constraint to guide early motor behaviour? (first thing to consider)

Answer 3

no
- recent evidence suggests that movement also affects brain development (interaction is key)
- this helps to explain movements that had not really been considered by earlier researchers: those appear randomly or spontaneously
ex. if you place an infant on their back, what movements will likely occur?

Question 4

are (infant movements) these type of movements reflexive?

Answer 4

no
- they occur in the absence of any apparent stimululs (or for any apparent reason)
- they are spontaneous (stereotypie) movements

Question 5

define spontaneous movements

Answer 5

infant movements that occur without any apparent stimulation
ex. supine kicking, spontaneous movements

Question 6

What did Thelen et al study?

Answer 6

1985-1995
- studied supine kicking movements by analyzing position and timing of limb segments

Question 7

describe supine kicking (Thelen and colleagues)

Answer 7

• movements are not random
• they are rhythmic and coordinated
• ankle, knee and hip joints move cooperatively (not independently)

Question 8

supine kicking patterns are not as random as we thought - they appear to be _

Answer 8

early precursors of walking

Question 9

break down supine kicking into 6 steps

Answer 9

• from extended position flexion begins
• hip and knee flexing ankle dorsiflexing
• hip knee and ankle fully flexed; pause
• extension begins with knee extension
• hip and knee extending, ankle plantarflexing (toe pointing)
• end of extension phase: between-kick interval
  *if you pretend they are standing, resembles walking
  flexion>pause>extension>between kick interval

Question 10

why are infants less efficient at walking movements* (not in notes)

Answer 10

infants tend to co-contract their muscles vs adults who only contract what they need and are more efficient
- infants more variable

Question 11

what patterns appear to be early precursors of grasping?

Answer 11

• spontaneous arm movements (pre-grasp reaching)
• again, high degree of coordination of elbow, wrist and finger joints
  note: the fingers do not extend independently

Question 12

What is related to being tired?

Answer 12

head banging*

Question 13

why dp stereotypies exist?

Answer 13

• newborn musculature is underdeveloped
• lack of ability to produce interntional, goal-directed movements

Question 14

what is the original theory for spontaneous movements

Answer 14

movements are extraneous, with no purpose

Question 15

what is the current theory for spontaneous movements

Answer 15

• movements are “building blocks,” which are similar to, and serve as a function for some voluntary movements
• the developing brain results in the generation of these movements (maturational)
• the movements in turn shapethe development of the brain (ecological)

Question 16

(infantile) reflexive movements occur quickly after _

Answer 16

the onset of stimuli

Question 17

describe infantile reflexes

Answer 17

• they involve single muscle or specific group of muscles (not the whole body)
• they cannot be extinguished at any one time
• persistence may indicate neurological problems

Question 18

describe infantile reflexes (cont’d)

Answer 18

• they are involuntary stereotyped movement responses to a particular stimulus
• dominant movement from during the last 4 months of prenatal life (iex. begin to develop in utero) and the first 4 months after birth
• occur subcortically (below the level of the higher brain centers)

Question 19

why do infantile reflexes occur?

Answer 19

• built-in response, facilitates survival
• allows interaction with the environment
• reflexive movements result in sensory consequences, stimulate development
• during later portion of reflexive period, reflexes are modulated ‘building blocks’ for future movement

Question 20

what are the general types of infantial reflexes?

Answer 20

• primitive
• postural
• locomotor

Question 21

what is the purpose of primitive infantial reflexes?

Answer 21

survival and protection

Question 22

what is the purpose of postural infantial reflexes?

Answer 22

reaction to gravity

Question 23

what is the purpose of locomotor infantial reflexes?

Answer 23

resemble voluntary locomotion

Question 24

what 7 primitive reflexes did we talk about in class?

Answer 24

• asymmetric tonic neck reflex
• symmetric tonic neck reflex
• doll-eye reflex
• palmar grasping
• moro reflex
• sucking reflex
• babinski reflex

Question 25

describe the asymmetric tonic neck reflex

Answer 25

- infant starts in supine position stimulus: turn head to one side response: same-side arm and leg extend - facilitates bilateral body awareness - facilitates hand-eye coordination - also called 'bow and arrow' or 'fencer's' position

Question 26

describe the symmetric tonic neck reflex

Answer 26

infant starts sitting stimulus: tip forward response: neck and arms flex, legs extend (tip back, neck and arms extend, legs flex) - facilitates equilibrium (vestibular development) - persistence may impede many motor skills and cause spinal flexion deformities *may act as warningsigns if they continues to have these past a certain age

Question 27

describe the doll-eye reflex

Answer 27

infant starts in vertical position stimulus: movement to supine and back to vertical response: eyes open and close - facilitates vestibular development - triggers of sleep and alertness

Question 28

describe palmar grasping

Answer 28

stimulus: touch palm with finger or object response: hand closes tightly around object

Question 29

describe the moro reflex

Answer 29

infant starts in vertical position stimulus: suddenly but gently lower baby's head response: arms and legs extend rapidly - may signify CNS dysfunction if lacking - may signify sensory motor problem if persists - may delay sitting and head control if persists - may indicate injury to one side of brain if asymmetrical

Question 30

describe the sucking reflex

Answer 30

stimulus: touch face above or below lips response: sucking motion begins

Question 31

describe the babinski reflex

Answer 31

infant starts in any position stimulus: stroke sole of the foot from heel to toe response: toes fan out *if maintained, can indicate damage to corticospinal tract

Question 32

postural reflexes (postural reactions) facilitate_

Answer 32

posture maintenance in changing environment

Question 33

describe postural reflexes

Answer 33

- maintain head in an upright position(breathing) - aid in development of mobility (eg. righting and rolling) - help to develop equilibrium while in motion (eg. parachute) - postural reflexes typically appear after 2 months - they are typically sequential (ie. righting must occur before rolling) - initially similar to primitive reflexes, then incorporated into general repertoire of movements

Question 34

name the 3 postural reflexes we talked about in class

Answer 34

- derotative righting reflex - labytinthine righting reflex - parachute reflex

Question 35

describe the derotative righting reflex

Answer 35

- infant starts in supine position stimulus: turn head to one side, or turn legs and pelvis to other side response: body follows head in rotations, or trunk and head follow in rotation - facilitates equilibrium reactions

Question 36

describe the labyrinthine righting reflex

Answer 36

- infant starts in a supportive upright position stimulus: tilt infant reponse: head moves to stay upright - necessary for bringing the body into an upright position and to orient in relation to gravity

Question 37

describe the parachute reflex

Answer 37

infant starts upright stimulus: lower infant toward the ground rapidly response: legs extend (4 months) - tilt forward: arms extend (7 months) - tilt sideways: arms extend (6 months) - tilt backwards: arms extend (9 months)

Question 38

describe locomotor reflexes

Answer 38

- locomotor reflexes facilitate voluntary gait - they typically appear much earlier than the voluntary movement - they are rhythmic movements that begin to show classic elements of coordinated movement - crawling, stepping, swimming

Question 39

name the 2 locomotor reflexes we talked about in class

Answer 39

- stepping reflex - swimming reflex

Question 40

decribe the stepping reflex

Answer 40

starting position: held upright stimulus: infant upright with feet touching surface response: legs lift and descend - precursor to later voluntary walking - disappears after approximately 5-months (unless you hold the child upright in water, then it reappears)

Question 41

describe the swimming reflex

Answer 41

starting position: prone in water stimulus: place infant in or over water response: swimming! - not the oscillation movements (like a tadpole

Question 42

what is the purpose of reflexes?

Answer 42

some have clear reasons to emerge, others are less obvious - the roles have been described in 3 different ways: structural, functional, applied

Question 43

describe the structural role of reflexes

Answer 43

reflexes are a byproduct of the developing neurological system (hardwiring)

Question 44

describbe the functional role of reflexes

Answer 44

reflexes serve specific functions related to survival (breathe, eat, etc.)

Question 45

decribe the applied roles of reflexes

Answer 45

reflexes foreshadow volitional goal-directed movements

Question 46

our current though is that infantile reflexes serve as _

Answer 46

building blocks to voluntary movement

Question 47

describe the relationship between reflexes and voluntary movement

Answer 47

early researchers (eg. McGraw) believed that voluntary movement was not possible until reflexes had been inhibited (motor interference) researchers are seeing that other factors than just the nervous system are involved in motor development