Chapter 5 - Perceptual and Motor Development

Dynamic Systems Theory

Universal milestones are learned through the process of adaptation (crawling, reaching, walking)

-Motor development is an interaction between Cognitive, Motor and Perceptual systems

1. Infants modulate movement patterns to fit a new task by exploring/selecting possible configurations

2. Not a passive process in which genes dictate unfolding of a sequence of skills

3. Actively puts together a skill to achieve a goal within the constraints set by body/environment

Infant Reflexes

Built in reaction to stimuli, govern newborn’s movements (automatic, beyond their control)

-Genetically carried survival mechanisms, allows them to respond adaptively to their environment before they have had an opportunity to learn

Ex; Blinking, Babinski, Grasping, Startle, Rooting, Stepping, Sucking, Swimming, Tonic Neck

-Re-emergence of certain reflexes indicates degeneration of neuromotor systems

Gross Motor Skills

Large muscle activities (moving one’s arms, walking)

-Key milestones split into First and Second Year

First Year

Timing of these milestones may vary by as much as 2-4 months, experiences can modify onset of these accomplishments

Ex; Learning to walk can be promoted earlier; African babies carried on backs of mothers freely move their legs (greater development of leg muscle) thus they walk earlier

Second Year

Toddlers become more motorically skilled/mobile

1. 13-18 Months - Toddlers can pull a toy by a string, climbing stairs with hands and legs

• Development of hand-eye coordination, fine motor skills (Bilateral Coordination), spatial awareness, supportive legs/arms, balance

2. 18-24 months - Toddlers can walk/run stiffly for short distances, balance feet in a squatting position, walking backwards without losing balance (kinesthetic awareness), kicking a ball without falling, jumping in place

Early Childhood - Gross Motor Skills

Preschool child no longer makes an effort to stand upright/move around

-At 3 years: Hopping, running back-and-forth are performed with delight

-At 4 years: Children have become more adventurous (display athletic prowess/talents in instruments, some sports)

Middle and Late Childhood

Motor development becomes smoother and coordinted

Example: Mastery of sports (swimming, etc)

-In gross motor skills involving large-muscle activity, sex differences are observed; boys usually outperform girls

Fine Motor Skills

Finely tuned movements

-Example: Motor skills requiring finger dexterity

Infants

Initially, infants reach by moving their shoulders and elbows crudely swinging toward an object

-Later → Move their wrists, rotate their hands, and coordinate their thumb and forefinger

Refine their ability to grasp objects by developing two types of grasps: Palmer and Pincer Grasp

Palmer and Pincer Grasp

Palmer Grasp - Grabbing an object with palm

Pincer Grasp - Holding object between thumb and forefinger

Early Childhood - Fine Motor Skills

Age 3 - Children build high block towers, each block placed with intense concentration

-Perceptual-motor coupling and visual-tactile system not fully developed

Age 4 - Children’s fine motor coordination more precise

Age 5 - Children fine motor coordination improved

-Hand, arm, fingers move together under better command of the eye

Middle/Late Childhood - Fine Motor SKills

Increased myelination of CNS reflected in improvement of fine motor skills
Age 8-10 - Children use hands independently with ease/precision

-Children can now write rather than print words, letter size is smaller and more even

Age 10-12 - Children show manipulate skills similar to abilities of adults

-Complex, intricate, rapid movements

-Musical instruments, arts/crafts, construction tool

Girls outperform boys in fine-motor skills

Techniques Measuring Infant Perceptual/Cognitive Skills

1. Preferential looking paradigm

2. Habituation

-Uses natural response of infants when interested in something

3. Evoked potentials (EEG)

4. High-amplitude sucking

-Non-visual psychophysical techniques

Preferential Looking Paradigm

Two stimuli presented simultaneously, observe whether infant attends to one more than the other

-Measures infant discrimination (e.g, faces/visual patterns)

Assumes that if an infants looks at one more than the other, they prefer the stimulus/can discriminate patterns

Preferential Paradigm - Problem

What if an infant shows no interest/equal interest… Two possibilities:

1. Equal preference for stimuli

2. Failure to discriminate between stimuli

• Can then be determined via Habituation

Habituation Method (Familiarization-Novelty)

Learning phase, repeatedly presents stimulus to infant until it becomes familiar

-Infant habituates to stimulus, stops responding to stimulus (head, eye movements, respiration, heart rate)

-Present second/novel stimulus (dishabituation, results in recovery of response)

If infant fails to attend (no recovery of response) → unable to discriminate

Recovery in response means infant able to discriminate difference between stimuli