Slide presentation for PSY 375

1. PSY 375:
LIFE-SPAN DEVELOPMENT
Motor, Sensory, &
Perceptual Development
Week 4

2. Motor Development:
The Dynamic Systems View
Dynamic systems theory: infants assemble motor skills
for perceiving and acting
Motivation leads to new motor behaviors, which are
“tuned” with repetition
New motor behaviors are therefore the result of the
body’s physical properties, nervous system
development, the goal the child is motivated to reach,
and environmental support
• Crawling, reaching, walking

3. Motor Development:
The Dynamic Systems View

4. Motor Development: Reflexes
Reflexes allow infants to respond adaptively to the
environment before they have had the opportunity to learn
Rooting reflex: when an infant’s cheek is stroked or the side
of the mouth is touched, the infant turns its head and tries
to find something to suck
Sucking reflex: occurs when infants suck an object placed in
their mouth
Moro reflex: a startle response to sudden, intense noise or
movement
Grasping reflex: infants tightly grasp any object placed in
their palm

5. Motor Development: Reflexes
• Some reflexes persist throughout life
• Some reflexes are incorporated into more complex
voluntary actions
• Grasp reflex then transitioning into infant reaching out
and grasping objects

6. Motor Development:
Gross Motor Skills
Gross motor skills are those that involve large-muscle
activities, such as moving one’s arms or walking
The development of posture
• Gross motor skills development requires postural control
• Dynamic process linked with:
• Sensory information in the skin, joints, and muscles, which tell us
where we are in space
• Vestibular organs in the inner ears that regulate balance and
equilibrium
• Vision and hearing

7. Motor Development:
Gross Motor Skills
Learning to walk
• Locomotion and postural control are closely linked, especially
in walking upright
• Infants discover places and surfaces that are safe for
locomotion
Motor development milestones and variations
in the first year
• Timing of motor development milestones varies by as much as
two to four months
• Experiences can modify the onset of accomplishments
• Infants develop new skills with caregiver guidance

8. Choose from these 2 figures
• Is one more problematic than the other?
• Think back to what you learned during the first
week of class regarding the nature of development

10. MilestonesinGrossMotorDevelopment

11. What do you think?

12. Motor Development:
Gross Motor Skills
Development in the second year
• Infants are able to explore the environment more extensively
and initiate social interaction with others
• By 13 to 18 months, many toddlers can pull a toy by a string
and climb steps
• By 18 to 24 months, many can walk quickly or run stiffly,
balance on their feet, walk backward, stand and kick or throw
a ball, and jump in place

13. Motor Development:
Gross Motor Skills
Cultural variation in guiding infants’ motor
development
• Mothers in developing countries stimulate their infants’ motor
skills more than mothers in developed countries
• Massage and stretch infants during daily bath
• When caregivers provide babies with physical guidance or give
them opportunities for exercise, infants often reach motor
milestones earlier
• Forms of restricted movements have been found to delay
motor development
• Examples: orphanage restrictions

14. Gross Motor Skills in Childhood
Young children enjoy simple movements for the sheer
delight of performing activities
• Examples: hopping, jumping, running back and forth
With age, children perform more adventurous physical
movements and display athletic prowess
• Motor skills become smoother and more coordinated
• Organized sports are one way to encourage motor skill
development

15. Gross Motor Skills
in Adolescence and Adulthood
Gross motor skills improve through adolescence
Adults reach the peak of physical performance before
age 30
• As we learned before, decline in general biological functioning
begins at about age 30

16. Gross Motor Skills
in Adolescence and Adulthood
Older adults move more slowly, especially for
movements with a wide range of difficulty
• Adequate mobility is important for maintaining an active and
independent lifestyle in late adulthood
• Falls are the leading cause of injury deaths among adults age
65 or older

17. Motor Development: Fine Motor Skills
Fine motor skills involve finely tuned movements, such
as any task requiring finger dexterity
Infants have hardly any control over fine motor skills at
birth
• Infants refine their ability to grasp objects
• Palmer grasp: grasp with whole hand
• Pincer grip: grasp small objects with thumb and forefinger
• Perceptual-motor coupling is necessary to coordinate grasping
• Perceptual system used varies with age
• Experience plays a role

18. Fine Motor Skills in Childhood and
Adolescence
As children age, their fine motor skills improve
• Increased myelination of central nervous system supports
improvement of fine motor skills
• Children begin to use hands more skillfully as tools
At ages 10 to 12, children show manipulative skills
similar to the abilities of adults
• Complex, intricate, and rapid movements
• Produce fine-quality crafts or play a difficult piece of music

19. Fine Motor Skills in Childhood and
Adolescence

20. Fine Motor Skills: Adult Development
Skills may decline in middle and late adulthood
Dexterity decreases
• Skill in performing tasks with hands
• Examples?
Pathological conditions may result in weakness or
paralysis of an individual’s hands
• Fine motor skill performance may be impossible

21. Sensory and Perceptual Development
Sensation: reaction that occurs when information
interacts with sensory receptors
• Sensory receptors: eyes, ears, tongue, nostrils, and skin
• Hearing involves the cochlea and auditory nerve
• Vision involves the retina and optic nerve
Perception: the interpretation of what is sensed
• Specific color or shape or pattern

22. Sensory and Perceptual Development:
The Ecological View
According to the ecological view, we directly perceive
information that exists in the world around us
• Perception brings people in contact with the environment in
order to interact with it and adapt to it
Affordances: opportunities for interaction offered by
objects that fit within our capabilities to perform
activities
• Example: a pot you cook with can also be something to bang
on

23. Sensory and Perceptual Development:
Visual Perception
At birth, the nerves, muscles, and lens of the eye are
still developing
• Newborns cannot see things that are far away
• Newborns’ vision is estimated to be 20/240 on the Snellen
chart used for eye examinations
Infants show an interest in human faces soon
after birth and can perceive certain patterns
Infants’ color vision gradually improves during the first
months of life

24. Vision
Newborn

25. Vision
4 weeks

26. Vision
8 weeks

27. Vision
3 months

28. Vision
4 months

29. Vision
6 months

30. Sensory and Perceptual Development:
Visual Perception

31. Sensory and Perceptual Development:
Visual Perception
Development of perceptual constancy allows infants to
perceive their world as stable

32. Sensory and Perceptual Development:
Visual Perception
Beginning at about 2 months of age, infants develop
the ability to perceive partly occluded (hidden) objects
as whole
• Learning, experience, and self-directed exploration via eye
movements appear to play key roles
Might infants even perceive depth?
• Visual cliff experiment
• Researchers do not know exactly how early depth perception
develops; but infants use binocular cues to depth by about 3
to 4 months of age

33. Visual Perception in Childhood
Changes in perceptual development continue in
childhood
Children become increasingly efficient in detecting
boundaries between colors at 3 to 4 years of age

34. Visual Issues in Childhood
Amblyopia is a common condition to be treated early
Many preschool children are farsighted, unable to see
close up as well as they can see far away
By first grade, most children can focus their eyes and
sustain attention effectively on close-up objects

35. Visual Perception in Adulthood
Vision changes little until the effects of aging emerge
• Declines occur in visual acuity, color vision, and depth perception
Accommodation of the eye, the eye’s ability to focus and
maintain an image on the retina, declines most sharply at
40 through 59 years of age
• Presbyopia (farsightedness due to loss of elasticity), difficulty
viewing close objects, and increased blind spot
• Declines become more pronounced in late adulthood
Visual processing speed declines; night driving becomes
difficult; dark adaptation is slower; and the visual field
becomes smaller

36. Sensory and Perceptual Development:
Hearing
During the last two months of pregnancy, the fetus can hear
sounds outside of the womb
Newborns cannot hear soft sounds as well as adults
• By 3 months, perception improves; but it does not reach adult levels
until 5 to 10 years of age
Infants are more likely to hear high-pitched than
low-pitched sounds
By 6 months, infants become more proficient at
localization—detecting the origin of a sound
Early hearing screening should be conducted

37. Hearing in Adolescence and Adulthood
Listening to loud sounds for a sustained period of time
is a risk factor for hearing problems
Few changes take place until middle adulthood
• Hearing can start to decline by age 40
• Sensitivity to high pitches usually declines first
Hearing impairment does not become much of an
impediment until late adulthood
• Older adults often don’t recognize they have a hearing
problem, deny they have one, or accept it as part of growing
old

38. Sensory and Perceptual Development:
Touch and Pain
Newborns respond to touch and can feel pain
• Practice of operating on newborns without anesthesia
Older adults may detect touch much less in lower
extremities (ankles, knees, etc.)
Estimated 60% to 70% of older adults report some
persistent pain
• Older adults have lower pain sensitivity for lower pain
intensities
• Severe pain affects memory and executive function tasks

39. Sensory and Perceptual Development:
Smell
Newborns can differentiate odors
Decline in sensitivity to odors may occur as early as the
twenties

40. Sensory and Perceptual Development:
Taste
Sensitivity to taste is present before birth
• Newborns learn tastes prenatally through the amniotic fluid
and in breast milk after birth
• At about 4 months, they begin to prefer salty tastes
Many older adults prefer highly seasoned foods to
compensate for diminished taste and smell

41. Intermodal Perception
Intermodal perception: the ability to integrate
information about two or more sensory modalities,
such as vision or hearing

42. Intermodal Perception
Intermodal perception: the ability to integrate
information about two or more sensory modalities,
such as vision or hearing

43. Nature/Nurtureand Perceptual
Development
Nativists view the ability to perceive the world in a
competent, organized way as inborn or innate
Empiricists emphasize the role of learning and
experience
Much of early perception develops from innate
foundations, and the basic foundation of many
perceptual abilities can be detected in newborns,
whereas other abilities form maturationally
• As infants develop, environmental experiences refine and
sometimes promote perceptual functions

44. Perceptual-Motor Coupling
Distinction between perceiving and doing has been
called into question by a number of experts
• Perceptual and action do not occur in isolation, but
instead are coupled
• Infants learn new perceptual-motor coupling by assembling
skills for perceiving and acting
Age-related declines are experienced in
perceptual-motor coupling in middle and late
adulthood
• Older adults can compensate, and may see improvement with
cognitive training