1. Chapter 5: Physical Development in Infants and Toddlers
MODULES
5.1 Healthy Growth
5.2 The Developing Nervous System
5.3 Motor Development
5.4 Sensory and Perceptual Processes
Copyright © 2009 Pearson Education Canada

2. Copyright © 2009 Pearson Education Canada
Module 5.1 Healthy Growth
LEARNING OBJECTIVES
Outline the important features of physical growth in infants and toddlers and how they vary from child to child.
Describe how heredity, hormones, and nutrition contribute to physical growth.
Summarize how malnutrition, disease, and accidents affect infants’ and toddlers’ physical growth.
Copyright © 2009 Pearson Education Canada

3. Features of Human Growth
Follows the cephalocaudal principle.
Muscles become longer and thicker.
During the first year, a layer of fat is added.
Cartilage is replaced by bone.
Copyright © 2009 Pearson Education Canada

4. Variations on the Average Profile
Secular Growth Trends: generational changes in physical development.
Average and normal are not the same.
Average Height and Weight
Copyright © 2009 Pearson Education Canada

5. Mechanisms of Physical Growth
Heredity influences adult height.
The pituitary gland secretes growth hormone.
Nutrition is particularly important during infancy when growth is rapid.
At 2 years, growth slows and kids become “picky” eaters.
Copyright © 2009 Pearson Education Canada

6. Challenges to Healthy Growth
Malnutrition is especially damaging in infancy.
Malnutrition needs to be treated with adequate diet and parent education.
Many diseases that kill young children are preventable with vaccines, improved health care, and changing habits.
After the first year of life children are more likely to die from accidents than from any other single cause.
Copyright © 2009 Pearson Education Canada

7. Module 5.2 The Developing Nervous System
LEARNING OBJECTIVES
Be able to draw a nerve cell and identify its major parts.
Discuss how the brain is organized.
Identify when the brain is formed during prenatal development and when different regions of the brain begin to function.
Copyright © 2009 Pearson Education Canada

8. Organization of the Mature Brain
Neuron: basic unit of nervous system, specializes in transmitting information.
Synapse: a gap or space between neurons.
Cerebral hemispheres: right and left halves of the cortex.
Frontal cortex: area of the cortex that controls personality and the ability to carry out plans.
Copyright © 2009 Pearson Education Canada

9. Copyright © 2009 Pearson Education Canada
The Developing Brain
Brain originates in neural plate.
Brain regions specialize early (e.g., left hemisphere for verbal functioning; frontal cortex for emotion).
“Flexible” or neuroplasticity of brain organization shown by children who recover from brain damage.
Copyright © 2009 Pearson Education Canada

10. Module 5.3 Motor Development
LEARNING OBJECTIVES
State how reflexes help infants interact with the world.
Detail the component skills involved in learning to walk, and at what age infants typically master them.
Describe how infants learn to coordinate the use of their hands and why most children begin to prefer to use one hand.
Discuss how maturation and experience influence children’s acquisition of motor skills.
Copyright © 2009 Pearson Education Canada

11. Copyright © 2009 Pearson Education Canada
The Infant’s Reflexes
Newborns’ reflexes prepare them to interact with the world.
Some reflexes are important to survival (e.g., rooting and sucking).
Some protect the newborn (e.g., blink and withdrawal).
Some are foundations for later motor behaviour (e.g., stepping reflex).
Copyright © 2009 Pearson Education Canada

12. Copyright © 2009 Pearson Education Canada
Locomotion
Dynamic Systems Theory: motor development involves many distinct skills.
Differentiation and integration of component skills (posture and balance, stepping, perceptual skill) is necessary.
Source: Based on Shirley, 1931, and Bayley, 1969
Copyright © 2009 Pearson Education Canada

13. Copyright © 2009 Pearson Education Canada
Fine Motor Skills
Maturation, Experience,
and Motor Skill
Reaching and grasping becomes more coordinated throughout infancy.
Toddlers prefer to use one hand and this preference becomes stronger during the preschool years.
Maturation is important: Studies of Hopi infants.
Experience matters, too: African infants and training studies.
Copyright © 2009 Pearson Education Canada

14. Module 5.4 Sensory and Perceptual Processes
LEARNING OBJECTIVES
Describe the sensory abilities of the newborn.
State how well infants hear and how they use sounds to understand the world.
State how accurate infants’ vision is and whether they perceive colour and depth.
Summarize how infants integrate information from different senses.
Copyright © 2009 Pearson Education Canada

15. Copyright © 2009 Pearson Education Canada
Hearing
Smell, Taste, and Touch
Infants hear well, though not quite as accurately as adults.
-Auditory threshold: the quietest sound that a person can hear.
Infants’ can distinguish different sounds and use sounds to judge the distance and location of objects.
Even newborns can smell, taste, and feel.
These skills are useful in recognizing their mothers and in feeding.
Copyright © 2009 Pearson Education Canada

16. Copyright © 2009 Pearson Education Canada
Seeing
Acuity is 20/400 at birth but improves rapidly.
Infants perceive colours by 3 or 4 months.
Infants master perceptual constancies early.
Many cues are used to infer depth.
Edges & motion are used to perceive objects.
Wavelength of Light
Copyright © 2009 Pearson Education Canada

17. Copyright © 2009 Pearson Education Canada
Infants’ Scanning of Faces
Perception of Objects
Face-like Stimuli
Use of Motion to Perceive Objects
Copyright © 2009 Pearson Education Canada

18. Integrating Sensory Information
By 1 month, can integrate sight and touch.
By 4 months, can integrate sight and sound.
4- and 7-month-olds can match facial appearance (boy or man) with sound of voice.
Copyright © 2009 Pearson Education Canada

19. Time Spent Looking at Videos Infant Watching Videos
Copyright © 2009 Pearson Education Canada

20. Copyright © 2009 Pearson Education Canada
Conclusions
Nutrition is important for physical growth in children.
The brain and nervous system develop throughout childhood through synaptic pruning and myelination.
Infants are born with many reflexes while their locomotor skills progress through a series of milestones and reflect maturation and experience.
Soon after birth, infants coordinate information from different senses (vision, hearing, smell, touch). They recognize by sight an object they have touched before and integrate what they hear with what they see.
Copyright © 2009 Pearson Education Canada