chapter 4 motor development

spontaneous movement

-Original theory: extraneous, no purpose

- Current theory: building blocks, similar to some voluntary movements we will see later in life

supine kicking and walking

Kicking was not random

Showed rhythmic and coordinated movements

-thelen

What characterizes spontaneous arm movements?

Well-coordinated extension of the elbow, wrist, and finger joints

How do spontaneous arm movements differ from kicking?

Arm movements are not rhythmical or repetitious

How do early arm thrusts compare to adult reaching?

Early arm thrusts are not identical to adult reaching

What are infantile reflexes?

Involuntary movements that occur quickly after the onset of stimuli.

Do infantile reflexes involve the whole body?

No, they involve a single muscle or a specific group of muscles.

Can infantile reflexes be extinguished at any one time?

No, they cannot be extinguished at any one time.

What does persistence of infantile reflexes past normal age indicate?

It may indicate neurological problems.

What is the Babinski sign for infants under 2 years old?

Big toe up and other toes fan out (normal).

What is the Babinski sign for children 2 years and older?

All toes curl under (normal).

What is an abnormal Babinski sign?

Big toe up and other toes fan out (abnormal).

Do some reflexes persist throughout the lifespan?

Yes, some reflexes, like blinking, happen throughout the lifespan.

Are some reflexes only present during infancy?

Yes, some reflexes are present only during infancy.

What reflexes do newborns exhibit at birth?

Newborns exhibit strong primitive reflexes at birth.

How do primitive reflexes change over time?

Primitive reflexes tend to lose strength gradually.

When do primitive reflexes typically disappear?

Primitive reflexes typically disappear around 4 months.

What is the palmer grasp reflex?

The palmer grasp reflex occurs when an object touches the palm, causing the infant to grasp it.

What is the asymmetric tonic neck reflex?

The asymmetric tonic neck reflex occurs when the head is turned to one side, causing the arm and leg on the same side to extend.

What are postural reactions?

Automatically help the infant maintain posture.

What do postural reactions help an infant do?

Keep the head upright, which helps maintain breathing.

At what age do postural reactions usually appear?

Around 2 months.

What happens to postural reactions around 2 years of age?

They decrease in strength but are still present.

What is an example of a postural reaction in response to a push?

You have certain postural reactions to help you not fall down.

What is one function of postural reactions besides maintaining posture?

Helps roll over and attain a vertical (standing) position.

What are the three locomotor reflexes?

Swimming, Stepping, Crawling

When do locomotor reflexes appear in infants compared to voluntary movements?

They appear much earlier than corresponding voluntary movements.

When do locomotor reflexes typically disappear in relation to voluntary locomotor skills?

They typically disappear months before the infant attempts voluntary locomotor skills.

What is one purpose of reflexes?

Built-in responses facilitate survival.

How do reflexes interact with the environment?

Reflexes allow 'dialogue' with the environment.

What is a sensory consequence of reflexive movements?

Reflexive movements result in sensory consequences (adaptation).

What do reflexes provide for future movement?

Reflexes provide building blocks for future movement.

What is the structural philosophy of reflexes?

Reflexes are a byproduct of the human neurological system.

What is the functional philosophy of reflexes?

Reflexes exist to help the infant survive.

What are some survival functions of reflexes?

Eating, breathing, and grasping.

What is the applied philosophy of reflexes?

Reflexes prepare infants for future volitional movements.

What does volition refer to?

An act of making a choice or decision.

What did McGraw's early research in 1943 suggest about reflex inhibition?

Reflex inhibition had to occur before voluntary movement could begin.

What did Zelazo and Kolb's research in the early to mid-1970s demonstrate about the stepping reflex?

They found that the stepping reflex could be transformed into voluntary walking.

What was one of the findings of Zelazo and Kolb regarding the onset of voluntary walking?

They showed an increased stepping reflex and earlier onset of voluntary walking.

What did Thelen's research in 1983 and 1995 question about reflexes?

Whether reflexes had to be inhibited before voluntary movement could occur.

What did Thelen propose as a reason for the disappearance of the stepping reflex?

Other constraints, such as insufficient leg strength due to increased leg weight.

What was the focus of Thelen's experiment with infants aged 4-6 weeks?

She added leg weights equal to the weight gain in the first two months to observe the stepping reflex.

What did Thelen observe in the second half of her experiment with older infants?

Older infants submerged in water showed an increase in stepping frequency.

What is reflexive movement?

A response to external stimuli that is specific and localized.

What characterizes reflexive movement in terms of stimuli?

The same stimuli elicit the same response repeatedly.

What is spontaneous movement?

Movement that occurs without apparent external stimuli.

How is spontaneous movement characterized?

It is nonspecific and generalized, and not reproducible.

What are fundamental motor skills?

Basic skills that serve as building blocks for complex motor skills.

What is meant by cumulative sequential in motor milestones?

Motor skills develop in a cumulative and sequential manner.

What are specific movements in the context of motor milestones?

Movements that lead to general actions.

What are rate limiters in motor development?

Rate limiters are individual constraints that inhibit or slow the attainment of a motor skill.

How do rate limiters change during early childhood?

Rate limiters rapidly change during early childhood.

How can cultural norms influence motor development in infants?

Cultural norms can shape social interactions between infants and others and guide parental child-rearing practices.

What rate limiters may control the development of crawling?

Strength, balance, and coordinated movements.

What rate limiters may control the development of reaching?

Strength, balance, and coordinated movements.

What rate limiters may control the development of walking?

Strength, balance, and coordinated movements.

What are rate limiters for posture and balance in infants?

They involve coupling of sensory information and motor responses.

How do infants calibrate their sensory motor responses?

Infants continuously calibrate sensory motor responses.

When do postural reactions begin in infants?

Postural reactions begin around four months.

What is the purpose of postural reactions in infants?

They help maintain posture in a changing environment.

How do postural reactions evolve in infants?

Initially they are similar to reflexes, then they are incorporated into general repertoire.

What is derotative righting in infants?

It is a reaction where the body follows the head in rotation when the head is turned.

What is the stimulus for derotative righting?

Turning the head to one side or turning legs and pelvis to the other side.

What is the response of an infant during derotative righting?

The body follows the head in rotation, or trunk and head follow in rotation.

What is the parachute reaction in infants?

It is a reaction where legs and arms extend when the infant is lowered toward the ground rapidly.

What is the stimulus for the parachute reaction?

Lowering the infant toward the ground rapidly.

What milestone is achieved at 2 months of age?

Infant lifts head in prone position.

What milestone is achieved at 3 months of age?

Infant lifts shoulders and turns head.

What milestone is achieved at 5 months of age?

Infant rolls over and sits unsupported.

What milestone is achieved at 7 months of age?

Infant gets on hands and knees.

What milestone is achieved at 8 months of age?

Infant creeps on hands and knees.

What milestone is achieved at 9 months of age?

Infant pulls to stand and cruises furniture.

What milestone is achieved at 10 months of age?

Infant stands alone.

What milestone is achieved at 12 months of age?

Infant walks alone.

atypical development

development that deviates from the typical developmental pathway in a direction that is harmful to the individual