Lesson 5 Flashcards
What is brain plasticity?
refers to the brain’s ability to change and adapt because of experience and new learning. it’s also referred to as neuroplasticity and cortical remapping.
What is synaptic pruning?
rarely used connections are deleted and frequently used connections are strengthened.
this shows the brain is in a continual state of change from growth in early years to change and refinement in adulthood as we learn and experience.
how many synaptic connections are formed at the age of 2-3 yrs old?
the brain experiences rapid growth peaking at approx 15,000
research support for brain plasticity
aim - structural changes can be detected in the brains of people with extensive experience in spatial navigation.
procedure- taxi drivers underwent ‘the knowledge’ test which asses their ability to recall streets and routes. mri scans of 16 right handed male london taxi drivers ppt all have been driving for more than 1.5 years. scans were also taken of 50 healthy right handed males who did not drive for comparison.
findings - inc grey matter found in posterior hippocampus than in the matched control group.
changed with navigational experience - a correlation was found - more time spent as a taxi driver the greater the volume in the right posterior hippocampus.
conclusion - results provide support the idea of brain plasticity and suggests that experience can change the structure of the brain (enlarged hippocampus).
research support for brain plasticity
aim - examine stuctural changes could be detected in the brains of students as a result of learning.
procedure- study scanned brain of group of german medical students 3 months prior and after an exam. compared the scans of students who had not studied.
findings - students who were studying for exam showed learning - induced changes in parietal cortex and posterior hippocampus. these regions are related to memory retrieval and learning.
conclusion - results supported brain plasticity and suggests studying can change structure of the brain.
What is functional recovery?
a form of plasticity which follows on from trauma e.g. physical injury or stroke. the brain’s ability to redistribute or transfer functions usually performed by a damaged areas to other undamaged areas. also an example of functional recovery.
- brain also appears to show evidence of functional recovery. it is an example of neural plasticity.
- following on from any kind of trauma e.g. physical injury or a stroke, unaffected areas of the brain adapt and compensate for damaged areas.
What are mechanisms for recovery?
brain rewires and organises itself by forming new synaptic connections close to the area of damage. secondary neural pathways that would not typically carry out certain functions are unmasked to enable functioning to continue.
what is axon sprouting?
nerve endings grow and connect with other undamaged nerve cells to form new neuronal pathways
what is denervation super sensitivity?
this occurs when axons that do a similar job become aroused to a higher level to compensate for ones that are lost
What is recruitment of homologous areas?
on the opposite hemisphere to do a specific task eg if the broca’s area located in the left hemisphere responsible for speech production was damaged then an area on the right hemisphere might take over.
what is neuronal unmasking?
wall identified neuronal unmasking where dormant synapses open connections to compensate for a nearby damaged area of the brain. This allows new connections in the brain to be activated thus recovering any damage occuring in specific regions.
negative plasticity
prolonged drug use
60-80% of amputees
limitation - may have negative behavioral consequences.
brains adaption to prolonged drug use leads to poorer cognitive functioning in later life and leads to inc risk of dementia. 60-80% of amputees develop phantom limb syndrome (continued experiencing sensations in the missing limb as if it was still there).
shows plasticity can lead to negative and painful consequences, not considered by the theory and only outlines the positive.
brains ability to adapt is not always beneficial.
age and plasticity
strength
golf players
40 - 60 yrs old
strength supportive research available around brain plasticity continuing w inc age.
40hrs of golf training produced changes in the neural representation of movement in PPs aged 40-60. Researchers observed inc motor cortex activity in the novice golfers compared to a control group suggesting more efficient neural representations after training.
it does continue throughout lifespan because individuals within the age range of 40-60 were able to develop strong neural connections to help facilitate their learning and skills of playing golf.
infer that plasticity occurs throughout life and brain development isn’t bound to childhood.
real life application
strength
neurohabilitation
quality of life
functional recovery is the wider practical application in developing treatments.
spontaneous recovery of the brain is initially fast it tends to slow down over time. led to neurohabilitation which aims to aid recovery from a nervous system injury. treatment involves techniques such as movement therapy and electrical stimulation to counter the deficits in motor or cognitive skills following a stoke.
without research not possible to have these supervisions in place to account for the natural slowing down of spontaneous recovery post - trauma.
demonstrates that positive application of research in this area helps improve the cognitive functions of people suffering from injuries, thus improving quality of life.
cognitive reserve
limitation
recovery rates
limitation of functional recovery is level of education may influence recovery rates.
more time people with a brain injury has spent in education - taken as an indication of their cognitive reserve - the greater their chances of disability - free recovery.
40% of those who achieved DFR have more than 16 years education compared to 10% of those who have less than 12 yrs education.
therefore implies that people with brain damage who have insufficient dfr are less likely to achieve a full recovery.
