Localisation of function Flashcards
Define localisation of function
Localisation of function in the brain refers to the idea that specific areas of the brain are responsible for a particular function.
True or false, The motor, somatosensory, visual and auditory cortices are on both sides of the brain
True
What is hemispheric lateralisation
Each hemisphere of the brain is specialised to perform different functions
What are the main centres in the left hemisphere
Language centres
What is the main centre in the right hemisphere
Visual spatial processing
Define contralateral
Each hemisphere of the brain controls the opposite side of the body (the left hemisphere controls the right side of the body)
What is a cortex
The surface layer of the brain is referred to as grey matter
2-4mm thick
Folded for extra surface area
Myelinated axons give it a white appearence
Where is the occipital lobe located and what is its function
It is found at the back of the brain and is the smallest lobe
It is responsible for visual perception
What happens if there is damage to occipital lobe
- Leads to partial or complete loss of vision called cortical blindness
- Damage is contralateral
Where is the frontal lobe located and what is its function
It is located at the front of the brain
It controls voluntary movement, expressive language and it manages higher level executive function
What does the motor cortex do and where is it located
Located at the back of the frontal lobe in a region known as the precentral gyrus
Primarily responisble for voluntary muscle control.
Located in both hemispheres
What happens if there is damage to the Motor cortex (4)
Loss of muscle function
Paralysis
Impaired movement
Damage is Contralateral
What does the Somatosensory cortex do and where is it located
Responds to sensory sensations related to touch
Contralateral
Located in the parietal lobe in the postcentral gyrus
Using information from skin it can produce sensations of pressure pain and temperature
What happens if there is damage to one side of the somatosensory cortex (4)
- Loss of sensation
- Ignoring areas of the body
- Loss of ability in recognising objects by their feel which is known as agnosia
- Damage is Contralateral
What does the temporal lobe do
It is the location for auditory ability and memory acquisition
Where is the auditory cortex located and what does it do
Located at the top of the temporal lobe specifically the superior temporal gyrus
It recieves auditory information from the thalamus which recieves sound impulses from the cochlea
What happens if there is damage in the auditory cortex
- Inability to detect changes in a persons pitch or tone
- Cortical deafness
Where is the brocas area located and what is its role
In the left hemisphere in the frontal lobe
It is responsible for speech production and breathing patterns during vocalisation
What happens if brocas area is damaged
You get Brocas Aphasia–> difficulty producing fluent speech
This was found out after the post mortem of patient tan who could only say the word tan
Where is wernickes area located and what is its role
Left hemisphere in the uppper temporal lobe
Responsible for speech comprehension
What happens if there is damage to wedrnickes area
You get wernickes aphasia—> difficulty undertanding speech or written letters
What is global aphasia
Damage to both brocas and wernickes area which is the inability to produce speech or undertanst speech
Evaluations: Pros
- The case studies demonstrate that if a certain area gets damaged in the brain you lose the function that it is responsible for
- Modern brain scanning techniques such as fMRI support theresearch on language centres showing activation in the regions associated when healthy paitients perform language tasks
Evaluations: Cons
- The use of case studies are seen as unscientific, especially in brain research with damage often covering multiple regions, as seen when modern MRI scans were made of tans brain
- Motor and somatosensory functions are highly localised, however systems like languages are more distributed and some functions like consciousness appear not to be localised at all. suggesting the correct approach in arguing for the localised or hollistic nature of the brain is dependnet on the function
- Due to the high conectivity of the brain no one area is indepednet
Where is the prefrontal cortex located and what does it do (3)
- RIght at the front of the brain
- It is responsible for higher level functions
- Involved in orchestrating thoughts and personality expression
What happens if there is damage to the prefrontal cortex
Affects beahviour and the ability to plan
Often results in personality change
Where is the visual cortex located and what does it do
Located in the occipital lobe
It is responsible for visual processing functions - recieves visual information and integrates it, processing the data and sending it to be utilised elsewhere
It processes different types of information e.g. Colour shape movement etc
How does visual processing begin
Begins in the retina which connects the visual cortex via the optic nerve and the thalamus
What happens if there is damage to the visual cortex
Partial or complete blindness which can manifest in different forms
