Key concepts

• Stages of development:

  • pre-natal
  • childhood
  • adolescence
  • adulthood
• pregnancy:

  • by 3rd week, foetus has forebrain, midbrain and hindbrain
  • mid-pregnancy, brain connects to all parts of body
  • in 8th month, rapid brain and head growth
• childhood:

  • by 6 yrs, brain is already at 90% size
  • frontal lobes undergo development and grey matter in brain peaks
• adolescence:

  • grey matter pruned away
  • pruning is done backwards with prefrontal cortex remodelled last
  • rely on limbic system to make decisions
• adulthood:

  • brain's volume decreases
  • ventricles expand
  • biggest changes happen in frontal lobes and temporal lobes
• IQ:

  • intelligence quotient
  • average is 100
  • 2/3 of population have 85-115
  • 140+ is considered genius
• brain parts:

  • frontal lobes - concerned with behaviour, learning, personality and voluntary movement
  • prefrontal cortex - front of frontal lobes and deals with planning/decision making
  • limbic system - centre of brain and controls basic drives and emotions
  • temporal lobes - near the temples, concerned with vision, hearing and speech comprehension
• later stages of adulthood:

  • brain and spinal cord lose nerve cells and weight
  • nerve cells process messages slower
  • waste products collect in brain tissue
  • plaques and tangles in the brain
• newborns:

  • brain contains about 100 billion neurons
  • typical brain has over 100 trillion synapses
  • synaptic pruning happens mostly during childhood and adolescence
• Pre-natal development:

  * neural tube forms at 16 days

  * it later forms the spinal cord and brain stem

  * at 8 weeks, the neural tube divides into nerve cells and brain cells

  * other organs develop quicker and most of the brain development happens mid pregnancy

  * by the time the baby is born, there's already 100 billion neurons in place