Hemispheric Lateralisatin Flashcards
What is hemispheric lateralisation
The notion that certain functions are principally governed by one side of the brain
What has systematic research shown about brain lateralisation
That language centres are lateralised to the left hemisphere. The Broca’s area is thought to be responsible for the production of speech and damage to this area would lead to language deficits, whereas damage to the right hemisphere did not
What is the right hemisphere responsible for and what is the left responsible for?
Right hemisphere responsible for the left half of the body and left hemisphere is responsible for the right half of the body. If a patient experiences right sided paralysis, there is damage to the left hemisphere.
What are the two hemispheres of the brain connected by
A bundle of nerve fibres called the corpus callosum which enables information to be communicated between the two hemispheres which is why we can explain things processes by the right hemisphere. Many researchers suggest that the two hemispheres work together to form most tasks as part of a highly integrated system
Strengths brain lateralisation
Helps us understand how multitasking works - the fact that specific functions are located on different sides of the brain allows us to multitask. Lateralisation frees the other hemisphere that is not being used to engage in another task. Rodger’s et al found that in a chicken, brain lateralisation is associated with an enhanced ability to perform two tasks at the same time, finding food and being diligent for predators. Shows that lateralisation improves brain efficiency in cognitive tasks.
Additionally there is research support - patients who have extensive damage to left hemisphere can experience global aphasia (loss of speech production and comprehension). This suggest that language is lateralised to the left hemisphere
Disadvantages of lateralisatin
Lateralisation shifts with age and therefore not set in stone. Szaflarski et al found that language become more lateralised to the left hemisphere by the age if 25, but decreased after that and with most tasks becoming less lateralised in healthy adulthood. We should therefore be cautious in assuming that brain lateralisation is set in stone throughout life.
It does not explain brain plasticity since studies have shown that if one hemisphere is damaged, does not mean that the individual will have an abnormal brain - it has been shown that the other hemisphere can take over and do the job of both hemispheres demonstrating that plasticity can overcome the potential limitations of lateralisation
Evidence from split brain patients develop the ability to speak using right hemisphere showing that language is not lateralised to solely the left hemisphere
