background

• brain development is a complex process that begins in the embryonic stage and continues throughout life, the main three stages are:

  1. prenatal development
  2. infancy and early childhood
  3. adolescence
• prenatal development

  • neurogenesis- the creation of neurons begins early
  • cell migration- neurons move to their designated locations in the brain
  • synaptogenesis- formation of synapses
  • myelination- myelin sheath formation around nerve fibers, enhances signal transmission
• infancy and early childhood

  • rapid growth- brain undergoes substantial growth, establishing structures and connections
  • critical periods- sensitive to environmental stimuli for learning and development
  • language development- language processing and comprehension begin to specialise
  • motor skills- regions controlling motor functions develop, enabling movement and coordination
• adolescence

  • synaptic pruning- refining neural networks for efficiency
  • frontal cortex development- prefrontal cortex, not fully developed until 25
  • increased connectivity- ventral striatum connections get better, this focused on risk and reward seeking behaviours
• many researchers have speculated that teens that exhibit more risk taking behaviours are more likely to have less developed prefrontal cortices. the prefrontal cortex is involved in high level reasoning and decision making and continues to develop up until the mid-twenties, so it would make sense that a lack of development in this area may link to risk taking behaviours, as they are more likely to ignore potential negative consequences
• Galvan (2013)


  teens have a heightened sensitivity to rewards which can be seen by an exaggerated neural response in the ventral striatum (looked at by Casey). this means teens may be more likely to think about the rewards (not consequences) due to exaggerated activity in their brain.
• subjective value


  the subjective value of an object is used to help us make a decision about our behaviour. this involves the prefrontal cortex and ventral striatum. this gives teenagers a bigger sense of reward than for older adults, this may be influenced by the way teens value money.
• expected value


  which is the sum of all possible outcomes of a particular choice multiplied by their probabilities (trepel et al, 2005)