Hemispheric lateralisation Flashcards
What are spatial relationships?
- Right hemisphere appears to be dominant for spatial functions like finding your way
- Damage to the right hemisphere may result in difficulty with spatial tasks like remembering a route
What is recognising?
- Right hemisphere seems to be particularly dominant for recognising emotions in others
- Heller + Levy found that participants shown a split photo (half smiling/ half neutral) would recognise the emotion on the left side of the picture
What are the 2 main language processing areas?
- Broca’s area
- Wernicke’s area
What is Broca’s area?
- Identified in the posterior of the left frontal lobe on the left hemisphere
- Believed to be critical for speech production
- People with deficits who can understand language but can’t speak or write had lesions in their left frontal hemisphere, whereas people with damage in these areas in the right hemisphere didn’t have the same language problems
What is Wernicke’s area?
- Located in the posterior of the left temporal lobe
- Patients with a lesion in the Wernicke’s area can speak but can’t understand language (Wernicke’s aphasia)
- Processes speech
If the point is:
A strength of lateralisation of the brain is that there’s a lot of case studies on patients with damage to Broca’s and Wernicke’s areas that have demonstrated their functions.
What is the evidence and link?
Evidence- For example, Broca’s aphasia is an impaired ability to produce language identified from the ‘Tan’ case study; in most cases, this is caused by brain damage in Broca’s area. Wernicke’s aphasia is an impairment of language perception, demonstrating the important role played by this brain region in the comprehension of language. Both case studies showed that language was focused in the left hemisphere.
Link- This suggests that it is a reliable explanation due to the supporting evidence.
If the point is:
A weakness of lateralisation of the brain is that much of the evidence such as Wernicke’s and Broca’s areas comes from post mortem studies which investigate the brain after death.
What is the evidence and link?
Evidence- Although this may help to pinpoint areas of the brain involved in different functions, it’s not possible to refine the understanding of these functions by getting the participant to do further tasks.
Link- This means that the explanation may not be fully reliable because of the way that findings from research are gathered.
If the point is:
A strength of lateralisation of the brain is that there is further evidence that the two hemispheres process information differently.
What is the evidence and link?
Evidence- For example, Fink used PET scans to identify which areas of the brain were active during a visual processing task. When participants with a connected brain were asked to focus on the global elements of a task, regions of the right hemisphere were more active. When focused on finer detail, the left hemisphere was more active.
Link- These findings imply that research into lateralisation of the brain offers a correct explanation of the 2 hemispheres and their processes.
If the point is:
A weakness of lateralisation of the brain is that research has found that lateralisation patterns shift with age.
What is the evidence, explanation and link?
Evidence- Szaflarski et al found most tasks generally become less lateralised in healthy adulthood.
Explanation- Some research has found clear differences between young children’s brains and adult brains with regards to lateralised abilities.
Link- This suggests that conclusions on localised and lateralised functioning need to take into account the role of age and experience.
What are the evaluations for hemispheric lateralisation?
+ There’s a lot of case studies on patients with damage to Broca’s and Wernicke’s areas that demonstrate their functions
— Much of the evidence, such as Wernicke’s and Broca’s area come from post mortem studies which investigate the brain after death
+ There is further evidence that the two hemispheres process information differently
— Research has found that lateralisation patterns shift with age
