Lateralisation & Split Brain Research Flashcards
Define the term hemispheric laterilisation (2)
- 🧠 split into 2 symmetrical halves called left/right hemisphere
- idea that 2 DIFFERENT hemispheres are responsible for different mental processes
eg LHS controls right side of body and is responsible for language
Explain the function of LHS
- recieves info from right visual field(RVF)
- controls right side of body
Explain function of RHS
- recieves information from LEFT VISUAL FIELD
- controls LEFT SIDE OF BODY
Define CONTRALLTERAL WIRING (2)
- TWO hemispheres work together by communicating through corpus callosum
- not all functions of brain is laterilised
Many Functions are not laterilised give three examples and why
- VISION
- MOTOR
- SOMATOSENSORY
- occur in BOTH hemispheres
What is the LHS responsible for? (2)
- language as two main centres Broca’s area responsible for speech production
- Wernicks area responsible for understanding language are located in LHS
What is RHS responsible for ? (2)
- recognition of faces places, objectives and creativity 👨🎨
- only produce rudimentary words and phrases but contributes to EMOTIONAL CONTEXT of what is being said
whats RTS
P - 😁 Sperry using split brain patients with a severed corpus collosum
E - found that ppts shown image of object to right visual field patients could name it verbally
> could identify object through pointing
E - supports idea that 🧠 is lateralised
and hemispheres responsible for language abilities
L - therefore supports theory of hemispheric laterilisation
Why has Sperry’s R been criticised ☹️
P - Individual differences in how laterilised ppts brain was
E - degree which corpus collosum was severed varied GREATELY
some having greater disconnection between two hemispheres than others
L - R may not be measuring effects of laterilisation effectively > reduces ⬇️ IV of
R therefore may not be appropriate for explaining hemispheric laterilisation not
How can HTS be discussed?
may not be appropriate explanation of how brain functions as R suggests brain has plasticity and rewires itself to compensate for any loss of function
WHATS RTC HEMISPHERIC LAT
P - case study EB
E - EB suffered from brain damage that resulted of removal of LHS
E - despite this after ⏱️ managed to regain some if his lang abilities which could not be possible if brain was completely lateralised (and only left responsible for language)
L - demonstartes that lang must be in >1 area of brain
therefore ❌arguing against laterilisation of function in brain
WHATS D point for EB
P - lacks pop val
E - not be appropriate to Gf on laterilisation of function to typical pop
as unique cases where brain damage may have affected way in which brain damage
L - these are unique case studies where brain damage may have affected the way in which the brain junctions and some individuals may be able to process language in the right hemisphere. some R has suggested that language is not solely lateralised to the left hemisphere but is found in the DOMINANT CEREBRAL HEMISPHERE > commonly found to be opposite to the DOMINANT HANDEDNESS
L- more research is needed with more diverse samples before firm conclusions on the lateralisation of language is possible.
Define Split brain (2)
- split brain patients have had surgery (normally to treat epilepsy) to cut area that connects two hemispheres of 🧠
(CORPUS CALLOSUM)
- Surgery may relieve epilepsy has major side effects
> two hemispheres become functionally seperate as act as 2 seperate independent brains
What is the aim of split brain R
- to investigate effect of severing connection between two hemispheres of 🧠
(corpus collosum) on functioning
What method and sample did sperry use?
- Natural experiment
- 11 I’s who had their corpus collosum severed due to surgery