Motor, Sensory, and Perceptual Development

Motor Development Sensory and Perceptual Development Perceptual-Motor Coupling

Dynamic Systems View

Seeks to explain how motor behaviors are assembled for perceiving and acting.

Motivation leads to new motor behavior; a convergence of: Nervous system development Body’s physical properties Child’s motivation to reach goal Environmental support for the skill

Motor Development

Reflexes

Built-in reactions to stimuli:Govern newborn’s movementsGenetically carried survival mechanismsAllow adaptation to environmentProvides opportunity to learnSome disappear (e.g.: grasping),

some last throughout life (e.g.: coughing)

Motor Development

ReflexesMotor Development

Moro reflex

Rooting reflex

Sucking reflex

Startle response in reaction to sudden, intense noise or movement

Reaction when infant’s cheek is stroked or side of mouth touched

Automatic sucking object placed in newborn’s mouth

Grasping reflexOccurs when something touches infant’s palms; infant response

is to grasp tightly

Gross Motor Skills

Motor skills that involve large-muscle activities (milestones achieved)Infancy

• Development of posture• Locomotion and crawling • Learning to walk• Help of caregivers important; cultural

variation exists• More skilled and mobile in second year

Motor Development

Motor Development

Milestones in Gross Motor Development

Gross Motor SkillsChildhood

• Improved walking, running, jumping, climbing, learn organized sports’ skills• Positive and negative sport outcomes• Movement smoother with age

Adolescence - Skills continue to improve

Adulthood • Peak performance of most sports before 30• Biological functions decline with age

Motor Development

Guidelines for Parents and Coaches of Children in Sports

Motor Development

The Don’ts– Yell or scream at child– Continue condemning– Point out errors in

front of others– Expect instant learning– Expect child to be pro– Make fun of child– Compare child to other– Make sports all work

The Dos– make sports fun– mistakes are okay– Allow questions,

show calm manner– Respect child’s

participation– Be positive role model – Be supportive

Motor Development

Movement and Aging

Fine Motor Skills

Involves more finely tuned movements, such as finger dexterity.

Infancy: Reaching and grasping• Size and shape of object matters• Experience affects perceptions and vision

Early Childhood: Pick up small objects• Some difficulty building towers• Age 5: hand, arm, fingers move together

Motor Development

Fine Motor Skills

Childhood and adolescence: • Writing and drawing skills emerge, improve• Steadier at age 7; more precise movements• By 10-12, can do quality crafts, master difficult piece on musical instrument

Adulthood: • Speed may decline in middle and late adulthood, but most

use compensation strategies• Older adults can still learn new motor tasks

Motor Development

Handedness Genetic inheritance proposed, unproven

Preference of using one hand over other

Right-handedness dominant in all cultures

Right hand preference in thumb-sucking begins in the womb

Head-turning preference in newborns

Preference later leads to handedness

Motor Development

Handedness, the Brain, and Cognitive Abilities

95% of right-handed primarily process speech in left hemisphere.

Left handed: Are more likely to have reading problems Show more variation Have better spatial skills More common among mathematicians, musicians, artists, and architects

Motor Development

What Are Sensation and Perception?

Sensation:Occurs when information contacts sensory

receptors.

Perception:Interpretation of sensation.

Sensory and Perceptual Development

The Ecological View

People directly perceive information in the world around them:

Perception brings people in contact with the environment to interact with it and adapt to it

All objects have affordances; opportunities for interaction offered by objects necessary to perform activities

Sensory and Perceptual Development

Studying Infant Perception

Visual preference method: To determine if infants can distinguish between various stimuli.

Habituation and Dishabituation: Habituation — decreased responsiveness to stimulus Dishabituation — recovery of habituated response

Tracking — moving eyes and/or head to follow moving objects

Videotape equipment, high-speed computers

Sensory and Perceptual Development

Infants’ Visual PerceptionSensory and Perceptual Development

Visual Acuity

Color

Perceiving Patterns

Depth Perception

Visual Expectations

20/600 at birth, near adult levels by 1 year

Sees some colors by 2 months, has preferences by 4 months

Prefer patterns at birth; face scanning improves by 2 months

Developed by 7-8 months

Begins by 4 months; all know visual cliff by 6-to-12 months

Perceptual ConstancySensory and Perceptual Development

Size constancy

Recognition that object remains the same even though the retinal image changes

Shape constancy

Recognition that object remains the same even though its orientation changes

Vision in Childhood

Improved color detection, visual expectations, controlling eye movements (for reading).

Preschoolers may be farsighted. Signs of vision problems:

Rubbing eyes, blinking, squinting. Irritability at games requiring distance vision. Closing one eye, tilting head to see, thrusting head forward to see.

Sensory and Perceptual Development

Aging Vision In Adulthood

Loss of Accommodation — presbyopia

Decreased blood supply to eye — smaller visual field, increased blind spot

Slower dark adaptation, decline in motion sensitivity

Declining color vision: greens, blues, vi

Declining depth perception — problems with steps or curbs

Sensory and Perceptual Development

Glare Vision and

Aging

Sensory and Perceptual Development

Diseases of the Eye

Cataracts — thickening eye lens that causes vision to become cloudy, opaque, distorted

Glaucoma — damage to optic nerve because of pressure created by buildup of fluid in eye

Macular degeneration — involves deterioration of retina

Sensory and Perceptual Development

Hearing

Sensory and Perceptual Development

Prenatal • Can hear before birth

Infancy • Improve sensitivity to soft sounds, pitches • Ability to localize

Childhood • Hearing usually fine • Danger of otitis media

Adolescence • Most have excellent hearing• Danger from loud music

Adulthood • Few changes until middle adulthood• Hearing impairment increases with age

HearingSensory and Perceptual Development

• Fetus hears in last 2 months of pregnancy• Newborns

– cannot hear soft sounds well– display auditory preferences – sensitive to human speech

• Infants less sensitive to sound pitch• Most children’s hearing is inadequate

• Otitis Media: middle ear infection

HearingSensory and Perceptual Development

• Adolescence– Most have excellent hearing; loud sounds poses risks

• Adulthood – Decline begins about age 40– Males lose sensitivity to high-pitched sounds sooner than females– Gender differences may be due to occupation– Treatment includes hearing aids

Other SensesSensory and Perceptual Development

Sense Infants Older Adults

Touch and Pain

Smell

Taste

Newborns feel pain; by 6 mos., can coordinate vision and touch

Can differentiate odors at birth; shows some preferences

May prefer sweet tastes before birth; likes salty at 4 months

Less sensitive to pain and touch in lower extremities

Loss of some sense of smell around age 60

Decline in taste of begins in 60s

Intermodal Perception

Ability to relate and integrate information about two or more sensory modalities, such as vision and hearing.

Exists in newborns; sharpens with experience in first year.

Sensory and Perceptual Development

Perceptual-Motor Coupling

Explores how people assemble motor behaviors for perceiving and acting

Controversial for some researchersBabies coordinate movements with perceptual

information to maintain balance, reach for objects, etc.

Driving a car is coupling; declines in late adulthood

Sensory and Perceptual Development