Physical Development

Question 1

Describe the development of the brain in terms of neural and synaptic changes and myelination

Answer 1

1. Overabundance of neurons formed in prenatal period
2. Number of synapses increase dramatically during infancy and childhood
3. Synaptic pruning: First stimulation results in massive overabundance of synapses, many of which serve identical functions
   - Neurons that are not needed lose their synapses
   - About 40% of synapses are pruned during childhood and adolescence
4. Myelination of neurons makes transmission of impulses faster and more efficient
   - Starts in infancy continues well into adolescence

Question 2

Describe typical reflexes of newborns

Answer 2

Sucking
- Sucking on objects placed into the mouth
Rooting
- Turning head towards object that touches cheeks
Babinski
- Fanning and then curling the toes when the bottom of the food is
stroked
Palmar grasping
- Curling the fingers around objects that touch palm
Stepping
- Infants held upright so that their feet touch a flat surface will step as
if to walk

Question 3

Describe the course of developmental changes that occur in gross motor skills

Answer 3

Two trends
- Head downward (cephalocaudal): Motor control of the head comes before control of arms and trunk, which comes before control of legs
- Center outward (proximodistal): Head, trunk, and arm control precedes coordination of hand and fingers
Increased differentiation and integration

Question 4

Compare and contrast different accounts for early motor development

Answer 4

1. Maturational view
   - Development of motor skills is hardwired in brain
2. Dynamic systems view
   - Motor skills are softly assembled as infants constantly recombine actions

they can perform into new and more complex action systems that help them to achieve their goals