Biopsychology: Lateralisation of Function NEW Flashcards
Define hemispheric lateralisation
The left and right hemisphere of the brain are responsible for different functions / The two hemispheres each have different functions and roles
State two functions of the left hemisphere
Language
Controls the right-hand side of the body
Receives information from the right visual field
Logic
Which two brain areas are in the left hemisphere that link to language?
Broca’s area
Wernicke’s area
State two functions of the right hemisphere
Recognition of faces, places and objects
Creativity
Controls the left-hand side of the body
Receives information from the left visual field
The right hemisphere can only produce rudimentary word and phrases but contributes to …
emotional context of what is being said
What do we mean by contralateral wiring?
Where the hemisphere controls the opposite side of the body e.g. the right hemisphere controls the left side of the body
Which functions are not lateralised as they are in both hemispheres?
Vision
Motor
Somatosensory areas
How does EB contradict lateralisation?
EB regained some language despite having his left hemisphere removed, so language must be in more than the left hemisphere
Why is the research to support hemispheric lateralisation criticised for individual differences?
The degree to which the corpus callosum was severed for each participant varied greatly, meaning there may still be some ability to communicate between the two hemispheres
Which hemisphere is responsible for language and logic?
Left
Which hemisphere is responsible for recognition and creativity?
Right
Which hemisphere controls the right-hand side of the body?
Left
Which hemisphere controls the left-hand side of the body?
Right
Which hemisphere receives information from the right visual field?
Left
Which hemisphere receives information from the left visual field?
Right
The right hemisphere is responsible for recognition of…
Faces, places and objects
Why is the left hemisphere responsible for language?
The two main language centres are located in the left hemisphere
Which hemisphere can only produce rudimentary words and phrases?
Right hemisphere
Which hemisphere contributes to the emotional context of what is being said?
Right hemisphere
Why are the vision, motor and somatosensory areas NOT lateralised?
They occur in both hemispheres
The left hemisphere receives information from the right visual field and controls the right side of the body.
What is this an example of?
Contralateral wiring
The right hemisphere receives information from the left visual field and controls the left side of the body.
What is this an example of?
Contralateral wiring
Give an example of contralateral wiring
The left hemisphere receives information from the right visual field and controls the right side of the body / The right hemisphere receives information from the left visual field and controls the left side of the body
Who can we use as research to contradict hemispheric lateralisation?
Case study on patient EB
What happened to patient EB?
Suffered from brain damage that resulted in the removal of his left hemisphere and therefore his language centres
What was found about patient EB?
Despite having no left hemisphere, after some time he managed to regain some of his language ability which would not be possible if the brain was completely lateralised
What does the research on patient EB demonstrate?
That language must be in more areas than just the left hemisphere
Which research demonstrates that language must be in more areas than just the left hemisphere?
Case study on patient EB
Why does the case study on patient EB demonstrate that language must be in more areas than just the left hemisphere?
Because EB managed to regain some of his language ability despite having his left hemisphere removed
Why might it not be appropriate to generalise the findings on the lateralisation of function to the typical population?
Because unique case studies are used, where brain damage may have affected the way in which the brain functions and some individuals may be able to process language in the right hemisphere
Research to contradict lateralisation of function lacks population validity.
What does this suggest is needed before firm conclusions on lateralisation of language can be made?
More research with more diverse samples
Who conducted research to support hemispheric lateralisation?
Sperry (1968)
What did Sperry find when participants were shown an image of an object to their right visual field?
They could name it verbally but when presented to the left visual field they could not name it verbally but could identify the object through pointing
How does Sperry’s research support hemispheric lateralisation?
Because when participants were shown an image of an object to their right visual field they could name it verbally, but when presented to the left visual field they could not name it verbally but could identify the object through pointing
What does Sperry’s research support?
That the brain is lateralised and that the hemispheres are responsible for different functions, such as the left being responsible for language abilities
Give one weakness of the research to support hemispheric lateralisation
Individual differences in the participants
What is the evidence for individual differences being an issue in the research to support hemispheric lateralisation?
The degree to which the corpus callosum was severed for each participant varied greatly, with some having a greater disconnection between the two hemispheres than others
Why is individual differences a weakness of the research to support hemispheric lateralisation?
Acts as a confounding variable and so the research may not be measuring the true effects of lateralisation
Which research supports that the brain is lateralised and that the hemispheres are responsible for different functions?
Sperry (1968)
Critics argue that individual differences was a confounding variable in the research to support hemispheric lateralisation.
What is a consequence of this?
The research may not be measuring the true effects of lateralisation, reducing the internal validity of hemispheric lateralisation
Sperry found that participants could name the object verbally when…
Objects were presented to the right visual field
Sperry found that participants could not name the object verbally but could identify it through pointing when…
Objects were presented to the left visual field
