Lesson 9- plasticity and functional recovery of the brain after trauma

Question 1

(neuro)plasticity

Answer 1

refers to the ability of the brain to adapt synapses, pathways and structures in light of various experiences, can be positive such as learning, or negative like recovery of function becuase of damage caused by trauma

Question 2

plasticity in the new born brain

Answer 2

-by end of first year brain has more neurones and synapses than it will have when fully mature
-developing brain is exposed to vast range of experiences environment, stimuli, brain has a lot to learn and to do= more plasticity
-Villablanca and Hovda (2000) hemispherectomy, occassionally baby is born with one hemisphere is severely damaged either through a genetic problem, illness, difficult birth, found that if that whole hemisphere is removed soon after birth as anadult person shows behavioural or congitive impairments

Question 3

plasticity as a result of life experiences

Answer 3

-as people gain new experiences nerve pathways that are used frequently develop stronger connection, however there is natural decline in cognitive functioning with age that can be due to changes in the brain
-led to researchers looking into ways in which new connections can be made to reverse this effect, Boyke et al 2008, found evidence of brain plasticity in 60 year olds taught a new skill-juggling, found increase in grey matter in the visual cortex, when juggling practice stopped the changes were reversed

Question 4

plasticity strengths

Answer 4

research support from animals
-Kemperman et al 1998, found an increased number of new neurons for rats housed in complex environmentscompared to rats housed in ordinary cages, specifically in hippocampus-associated with new memories and the ability to navigate from one location to another
-Blakemore and Mitchell 1973, able to show the characteristics of visual neurons could be permanently chagned by exposure to specific environments soon after birth, kittens reared in an environment with black vertical stripes did not respond to horizontal black stripes, shows how exposure to certain stimuli affects brain development
research support from humans
-Maguire et al 2000, studied london taxi drivers to discover whether changes in the brain could be detected as a result of their experience of spatial navigation, using MRI scanner researchers calculated the amount of grey matter in the brains of taxi drivers in comparison to control participants, found front of hippocampus was larger than controls, positively correlated to how long they had been driving taxis
-David et al 2004, compared 8 practioners of Tibetan meditation with 10 volunteer students with no previous meditation experience, both groups fitted with electrical sensors and asked to meditate for short periods, electrodes picked up much greater activation of gamma waves in monks, students only showed slight increase in gamma wave activity while meditating, concluded meditation changes short term workings of brain but may also produce permanent changes

Question 5

plasticity weaknesses