Plasticity and Functional Recovery of the Brain

• Brain plasticity refers to the brain's ability to change and adapt as a result of experience and new learning. Brain plasticity is also referred to as neuroplasticity and cortical remapping
• The brain experiences rapid growth in infancy, peaking at 15,000 synaptic connections by the age of 2-3
• Rarely used connections are deleted
• frequently used connections are strengthened
• The brain is in a continual state of change from growth in early years to a change and refinement in adulthood as we learn and experience
• Research studies that support plasticity include: Maguire et al (2000), Draganski et al (2006), Gaser and Schlaug (2003), and Michelli et al (2004)
• Maguire et al (2000) found that London taxi drivers had larger hippocampi than bus drivers or non-drivers due to their extensive knowledge of routes around London.
• Draganski et al (2006) found that people who learned to play an instrument showed increased grey matter density in areas associated with motor control compared to those who did not learn to play an instrument.
• The brain can repair itself after a stroke using functional recovery methods
• The brain can sprout and connect with new areas by connecting nerve endings with undamaged nerve cells
• brain can repair itself through neural repair or neural plasticity
• If the left side of the brain is damaged, the right side will take over
• Functional recovery is a form of plasticity which follows on from trauma, the brain's ability to redistribute or transfer functions usually performed by a damaged area to other undamaged areas
• Axon sprouting- nerve endings grow and connect with other undamaged nerve cells to form new neuronal pathways
• denervation supersensitivity- this occurs when axons that do a similar job become aroused to a higher level to compensate for ones that are lost
• Recruitment of homologous areas- using the opposite hemisphere to conduct a task
• Wall (1977) identified neuronal unmasking
• Neuronal unmasking is where 'dormant' synapses open connections to compensate for a nearby damaged area of the brain
• Gaser and Schlaug (2003) found that grey matter volume was higher in professional musicians (compared to non-musicians and amateurs) in areas responsible for motor function, visual input and object recognition
• Michelli et al (2004) found that bilingual brains have a larger parietal cortex (area responsible for language) than monolinguals
• Tariji et al (2013) investigated the role of stem cells in the recovery from brain injury
• Rats were used to investigate the effect of stem cells on brain injury recovery
• Three months after the brain injury, rats who received stem cells showed clear development of neuron-like cells in the area of injury. This was not the case with the control group
• STRENGTHS

  • Real life application
  • Age and plasticity
  • Support from animal studies
• WEAKNESSES

  • Negative plasticity
• Medina et al (2007) found that prolonged drug use led to poorer cognitive function in later life and a higher risk of dementia
• 60-80% of amputees develop phantom limb syndrome due to brain plasticity
• Kempermann et al (1998) found that rats who lived in more complex environments had an increased number of new neurons compared to lab cage rats
• Bezzola et al (2012) found that 40 hours of golf training led to positive changes in the neural representation of movement in participants aged 40-60