The Newborn or Neonate

n Appearance

n Large heard

n Bulging abdomen

n Splotchy skin

n Misshapen head

n Divergent eye-movements

Infant Exams

n APGAR Test

Infant Exams

Infant Exams

n Dubowitz Test: Used to estimate infants gestational age based on neurological items and measurements

n Neonatal Behavioral Assessment Scale (NBAS)

n 18 reflexes

n 27 items reflecting motor capacities, ability to control state, and response to stress

Infant Exams

n Concerns with accuracy

n Vary with babies state

n Have limited predictive validity

n Have high false alarm rates

n Are they useful?

The Newborn

n Innate Reflexes

n Grasping

n Rooting

n Sucking

n Babinski

n Moro

n Stepping

n Swimming

Physical Growth and Motor Development

n Whether size, complexity, or voluntary control--Growth is Directional

n From head to tail (eyes before feet)

n Center of body outward

n From mass to specific (large muscles before small muscles

n Skills become integrated: simple skills develop and then become integrated together

Physical Growth

n Systems develop independently

Physical Growth

n Relationship between norms and individual differences

n Norms are typically not very important

n No infants “hits” all the norms

n Variance is more critical especially when extreme

Cycles and States

n Sleep

n Both quiet and active or REM sleep

n High percentage of REM sleep

n Why does it decrease?

Cycles and States

Cycles and States

n From birth there are individual differences in the stability of state and the infants ability to control transitions between states.

n Over development, infants get better and regulating, maintaining, and transitioning between states

Why states are important

n They predict future complications—it is a marker of central nervous system integrity

n It represents how infants respond to the external world, e.g, visual, tactile, and auditory stimuli

n It effects how adults respond to infants

n The way babies are cared for can effect their ability to control state

n For example, Japanese babies have better state regulation and sleep patterns

State and Sleep Cycles

n It’s not until around 6 months that infants begin to develop diurnal sleep patterns

The Newborn

Central Nervous System Development

n Maturation of the Cerebral Cortex

n Neuronal Growth

CNS: How do we study?

n Positron Emission Tomography (glucose)

n Magnetic Resonance Imaging (MRI)

n Electroencephalography (EEG)

n Event Related Potentials (ERP)

Event Related Potentials

Event Related Potential

CNS Development

n Sub-Cortical Structures fully developed, however, there are changes in the Reticular Activating Formation

n Limbic System: also appear fully developed at birth, however, changes occur in pathways to higher cortical areas

n Cerebral Cortex undergoes significant maturation

Brain Maturation

n Beginning around 2 months there is a significant increase in dendritic branching

n To a lesser extent, axonal growth

n And a significant increase in synapses

CNS Development

CNS Development

n There is an overproduction of dendrites and axons which results in in subsequent elimination or “pruning”

n Why is there an excess?

CNS Development

n What determines which neuronal processes get pruned?

n Morphology and space limitations

n Activity

CNS Development

n William Greenough has suggested a distinction be made between:

n Experience-Expectant Processes: Processes common to all members of specie who in a normal environment undergo common overproduction and pruning

n Experience-Dependent Processes: Storage processes that reflect individual differences and are primarily related to formation of new synaptic connections

CNS Development

n Significant increase in myelination

n This results in a significant increase in the velocity with which neurons transmit their impulses

Brain Maturation