Brain Development: Maturation (DP IB Psychology): Revision Note

Brain development: maturation

• In the first few years of human life, more than 1 million new neural connections are formed every second

• Humans are born with a huge capacity to respond to their environment

• The human brain is hard-wired to take in the multitude of environmental stimuli that it encounters daily

• Some synapses are strengthened through repeated use and thus expand their network, which is known as neural branching

• About half of these connections are eliminated during adolescence to increase efficiency, which is known as neural pruning

• Brain development reflects the development of higher-order cognitive functioning

  • Evidence shows that the first areas of the brain to mature are those related to the most basic of functions e.g. movement and senses

• Functions such as decision-making, reflection and planning develop later (along with their associated brain areas)

• This sequence means that it is possible to see the connection between the developing brain and increasingly sophisticated cognitive functions

Research support for brain development

Chugani et al. (1998)

Aim:

• To investigate glucose metabolism in the human brain from birth to late adolescence in order to track the course of brain development and cognitive functioning

Procedure:

• A review article of positron emission technology (PET) scan studies on human brain development

Results:

• Newborns show reduced activity in the cerebral cortex (linked to executive functions) but activity in the amygdala, suggesting emotional responses are central to early interactions and development

• 6–9 months: activity increases in the frontal lobes, coinciding with improvements in cognitive functioning

• Windows of opportunity for skill development:

  • Motor skills: pre-birth – 6 months

  • Vision: 0 – 6 months

  • Emotion regulation: 0 – 3 years

  • Vocabulary and speech: 0 – 3 years

  • Logic (including maths): 0 – 4 years

• Missing these windows can have long-term, potentially devastating consequences for development

• There is a critical period in the first 10 years, particularly for the development of language structures (grammar rather than vocabulary)

 Evaluation of brain development

 Strengths

• PET scan studies are replicable if there is access to the equipment and trained staff who can operate the machines and analyse the scans

  • Chugani’s findings have been supported by other studies into brain development identifying the prefrontal cortex as being the last part of the brain to develop

  • This increases the reliability of PET scan research

• Understanding the progression of brain development can help to identify developmental delays in babies and children, which in turn can inform interventions and treatments

 Limitations

• Using PET scans may be biologically reductionist

  • They cannot account for other important influences on cognitive development

    • E.g., upbringing, peers, environment, which may all play an important role in brain and cognitive development

• Some children may not fall in line exactly with the windows of opportunity set out in Chugani’s research, which means that the findings do not account for individual differences

Link to concepts

Measurement

• The use of PET brain imaging technology on babies and younger children can give insights into the correlation between brain development and learning

• PET scans of babies and children can identify biological stages of brain development that peak at 10 years old, providing a ‘window of opportunity’ for learning

• This technology has allowed researchers to ‘look inside’ the brain in ways that were unimaginable just decades ago

Causality

• The use of PET scans is an example of an objective and clinical methodology which adheres to the features of science

  • A hypothesis can be tested under controlled conditions

    • However, this means that the method lacks ecological validity due to the artificial nature of the technique