Hemispheric Lateralisation Flashcards
AO1 for lateralisation
- define lateralisation
- identify which hemisphere is responsible for which task
- identify what hemisphere is responsible for which visual field and side of the body
- corpus collusom
- sperry and Gazanigas
What is hemispheric lateralisation?
-it is the theory that the brains left and right hemisphere are responsible for different specific functions
What enables communication between the two hemisphere?
Corpus callosum
What is the corpus callosum?
They are nerve fibres that enable communication between the left and right hemisphere
Describe what side of the body and visual field both hemispheres are responsible for
Left hemisphere- Right visual field and right side of the body
Right hemisphere- Left visual field and left side of the body
What was the sample used for Sperry’s research?
11 epileptic participants who had their corpus callosum cut out
What was sperry and Gazzanigas research aim and method
Aim: To investigate the extent both hemispheres of the Brain were specialised in certain functions
Method: -11 epileptic participants who had their corpus callosum cut out were investigated
- they had complete three tasks
- describe what u see task (they flashed an image at either the right or left visual field and where asked to describe what they saw)
- tactile test (an object was placed on either left or right hand and they were asked to identify what it was and pick a similar object up)
- drawing task (picture was presented to other the left visual field and were asked to draw with left hand and the opposite was done with the other hand and visual field)
Outline findings of sperry and gazzanigas research?
- on the drawing task they could only describe the object if the image was flashed in the right visual field
- In the tactile test they could only identify the item if it was placed in the right hand however they could pick up a similar object if the item was placed in both hands
- In the drawing task they could only draw clearly if the image was flashed in the left visual field and if they were drawing with the left hand
Conclusion of sperry and Gazzanigas research
The left hemisphere of the brain is specialised in language functions and test, while the right hemisphere is specialised in visual and motor functions
AO3 for hemispheric lateralisation
- language damage to the left hemisphere
- sperry praise and reverse patterns/inconsistency in findings
- age and lateralisation
Outline how sperry is praised and criticised
P: Sperry is praised as he conducted his first split brain experiment and he was the first to investigate hemispheric lateralisation.
E: His research has supported the claims that the left hemisphere is responsible for language tasks and the right is responsible for visual and motor tasks.
E: Even though he was the first pioneer into the investigation of hemispheric lateralisation a lot of other research contradicts his findings as they have shown their is a reverse pattern.
L: The inconsistency of findings on split brain research makes us unsure whether the left hemisphere is responsible for visual, motor tasks therefore Perry’s claims are weakened.
Outline the relationship with age and lateralisation
P: There has been research evidence showing that the dominance of hemispheres for specific functions changes with age.
E: The findings have suggested that the older we get the more language functions become lateralised to the left hemisphere
E: However this is only until the age of 25 as lateralisation decreases over each decade we get older
L: This makes us unsure wether one hemisphere has more dominance than other over certain functions as it is affected by age.
Outline AO3 paragraph for language and damage
P: It is argued language is not restricted to the left hemisphere
E: Patients who had suffered brain damage to the left hemisphere lost some ability for language production and comprehension
E: However they developed the capacity for those functions in the right hemisphere
L: This weakens the idea of lateralisation and that both hemispheres are specialised in certain functions as there is physical evidence showing us the right hemisphere can take over responsibility for language tasks.
