Localisation of function Flashcards
What is localisation of function?
Idea that specific functions (eg. language, memory, hearing) have specific locations in the brain
What did Pierre Flourens demonstrate?
Main divisions of brain were responsible for largely different functions
Who was Franz Gall?
- His theory of phrenology was the study of the structure of the skull to determine a person’s character and personality
- He was undoubtedly influential but his theory was discredited
What is the motor cortex responsible for?
generation of voluntary motor movements
Where is the motor cortex located?
- frontal lobe
- along precentral gyrus
How does the motor cortex control different parts of the body?
- it spans both hemispheres
- left part controls right side of body and vice versa
- regions are arranged logically next to eachother (eg. the region that controls the foot is next to the the region that control the leg and so on)
What does the somatosensory cortex do?
- Detects sensory events arising from different regions of the body
- Using sensory informations from the skin, it produces sensation of touch, pressure, pain and temperature
- Then locates it to specific body regions
Where is the somatosensory cortex located?
- Parietal lobe
- Along postcentral gyrus
What is the postcentral gyrus dedicated to?
The processing of sensory information related to touch
How does the somatosensory cortex recieve messages from different parts of the body?
- Like the motor cortex, both sides of the brain have a somatosensory cortex
- The cortex on one side of the brain receives sensory information from the opposite side of the body
Where is the primary visual centre of the brain located?
visual cortex in the occipital lobe
Where does visual processing begin?
- in the retina where light enters and hits rods and cones
- Nerve impulses from the retina are transmitted to the brain via the optic nerve
- Go to thalamus which acts as a relay station, passing the information on to the visual cortex
Describe the structure of the visual cortex?
- part on the right of the brain deals with left eye’s visual field
- part of cortex deals with different things (eg. colour, shape, movement)
Where is the auditory cortex?
Temporal lobes
Where do the auditory pathways begin?
- begin in cochlea in the inner ear (where sound waves are converted to nerve impulses)
- travel via the auditory nerve to the audititory cortex in the brain
What is the first stop after the cochlea?
the brain stem (where decoding takes place eg. duration and intensity of sounds)
Where does the auditory nerve impulse head to after the brain stem?
Thalamus
What is the role of the thalamus in hearing?
- acts as a relay station to send it to the auditory cortex
- carries out further processing of the auditory stimulus
What is the role of the auditory cortex as the sound has already been largely decoded by the brain stem and thalamus by this stage?
- sound is recognised
- and may result in an appropriate response
Who was Broca’s area named after?
French neurosurgeon, Paul Broca
Describe what Paul Broca found
- his patient could only say ‘tan’ but could understand speech
- other people with this problem also had damage to left hemisphere
- people with damage to right hemisphere didn’t have this problem
- Doiscovered language part of the brain was on the left hemisphere and named it Broca’s area
What did Fredorenko et al. find out about Broca’s area?
Fredorenko et al. found two regions of Broca’s area: one involved in language and other to many demanding cognitive tasks
Was Wernikes area discovered before or after Broca’s area?
Shortly after
Who was Carl Wernicke?
german neurologist who discovered another area of the brian involved in understanding language
Where is Wernickes area?
posterior portion of the left temporal lobe
What is the difference between Broca’s area and Wernicke’s area?
Broca’s = language production
Wernicke’s area = language comprehension
While damage in Broca’s area led to people unable to speak but can understand speech, damage to Wernicke’s area led to unable to understand language but able to speak
What did Wernicke propose?
- Language involves separate motor and sensory regions located in different cortical regions
- Motor region = Broca’s area
- Sensory region = Wernicke’s area
How are Wernicke’s area and Broca’s area connected?
- a neural loop known as the arcuate fasciculus
- One area at each end
