Lifespan Development Psychology - PSYC 2100
Lecture Block 4: Physical Development in Infancy and Toddlerhood
Physical Growth in Early Years
- Rapid Growth: Fastest growth in the first three years, especially the first few months.
- Birthweight:
- Doubles by 5 months (7 to 15 lbs)
- Triples by 1 year (22 lbs)
- Height:
- Gains 10-12 inches in the first year
- Gains 5 inches during the second year
- Gains 3-4 inches during the third year
- Motor Movements: Need recalibration due to longer limbs and more weight.
Teething
- Begins around 3-4 months.
- First tooth between 5-9 months.
- By age 1: 6-8 teeth.
- By age 2.5: 20 teeth.
Brain Development
- Growth Patterns:
- Cephalocaudal Principle: Growth proceeds from top to bottom.
- Proximodistal Principle: Growth proceeds from the inner body to the outer parts.
- Neural and Cerebral Cortex Development:
- Neurons form synapses, stimulated by environmental interaction.
- Glial cells support and insulate neurons with myelin.
Brain Structure
- 100 billion neurons and 100 trillion synapses in the human brain.
- Cerebral Cortex:
- Accounts for 70% of CNS neurons.
- Corpus Callosum: Connects two hemispheres.
- Frontal Lobes: Responsible for thought and planning.
Hemispheric Specialization
- Left Hemisphere:
- Language, analysis, positive emotions.
- Processes information sequentially.
- Right Hemisphere:
- Perceptual skills, emotion regulation, spatial skills.
- Processes holistically and simultaneously.
- Both hemispheres are involved in all learning tasks.
Sensitive Periods and Plasticity
- Environment and genetics interact to influence development.
- Plasticity: Young brains have a higher ability to recover and adapt after trauma.
Case Study: Dusty
- Born premature, faced multiple health challenges, but defied odds to become a highly functional adult.
Animal Experiments
- Experiments with kittens and rats demonstrate the importance of sensory stimulation.
- Deprivation can lead to permanent impairment.
Infant Development
Sleep Patterns
- By 6-9 months: 2 naps a day, totaling 12-13 hours.
- Cultural differences in sleep practices.
Nutrition
- Babies need twice as many calories per pound as adults.
- Breast Milk: Recommended for nutrition and immunity benefits.
- Emotional nourishment during feeding is important.
Learning and Conditioning
- Babies learn through sensory experiences, classical and operant conditioning.
- Habituation: Babies get bored with repetitive stimuli.
Classical and Operant Conditioning
- Classical conditioning involves pairing stimuli to produce a response.
- Operant conditioning strengthens or weakens behavior through consequences.
Motor Development
Major Milestones
- Pincer Grip: Using thumb and forefinger.
- Walking: Begins around the first birthday.
Motor Skills Development
- Rolling over, grasping, reaching, sitting, and walking have specific timelines.
- Experience and practice influence development.
Perception
Depth Perception
- Develops by 5 months; uses monocular and binocular cues.
Motion Perception
- Cues depend on eye muscles, retina, and environment.
Size and Shape Constancy
- Perception of objects remains constant despite changes in sensory input.
Face Perception
- Develops from focusing on outer edges to recognizing familiar faces.
- Preference for attractive faces observed at 5 months.
These notes capture key points from the lecture on physical and brain development in infancy and toddlerhood, highlighting significant growth patterns, motor development, brain specialization, and developmental psychology concepts.