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localisation of function in the brain - Coggle Diagram
localisation of function in the brain
defintions
localisation
different regions of the brain are responsible for specific cognitive/behavioural functions
hemispheric lateralisation
dominance of a particular hemisphere for specific functions
contralateral
right hemisphere controls left visa versa
somatotopically
controls fine (complex) motor movements
e.g hand movement
cerebral cortex (outer layer of brain)
contains left/right remispheres
made up on corpus callosum (fibres)
divided into four lobes
frontal
parietal
occipital
temporal
functions of these can be localised, later lateralised
4 localised regions
motor cortex
both hemispheres
in frontal lobe
responsible for generation of voluntary motor movements
sends neural msgs to muscles via CNS
contralateral
right hemisphere control MM in left side
any damage on one side will impact the opposite
somatotopically organised
has larger areas of the brain for hands vs feet
fine motor movements
somatosensory cortex
both hemispheres
parietal lobe
recieves sensory info
primary SS cortex detects sensory events arsing from receptor in dif areas of body
from skin- cortex produces sensations of touch/pressure/pain/temp
localised into specific body regions
contralateral
somatotopically organised
point-for-point correspondence of an area of the body to specific part of CNS
larger portion for hands vs back
auditory cortex
both hemispheres
temporal lobe
auditory pathways begin in cochlea in inner ear
sound waves converted in impulses
travel to brain stem
decodes
moves to thalamus
auditory cortex
damage=difficulty interpreting sound
contralateral
info goes from left ear to right hemisphere etc
visual cortex
primary visual centre
both hemispheres
occipital lobe
visual processing starts in retina
light enters
strikes photoceptors
optic nerve transmits nerve impulses from retina-brain
contralateral
right hem recieves info from left side
right visual field transmits to left hem etc
split into several areas
e.g V4 (process colour)
specific area for facial recognition
processes visual info (colour/shape)
damage can cause cortical blindness
loss of vision
visual input needs additional input from secondary sources
EV
S
supporting research
human clinical case studies
loss of specific abilities after specific brain damage
phineas gage
frontal lobe impaled with a pole
damage altered his personality from calm to quick-tempered
suggests the frontal lobe may be responsible for regulating mood
certain functions are localised
supporting research
human clincal case studies
loss of specific abilities after specific brain damage
receptive aphasia
damage to wernickes area
damage to areas of hippocampus
HM damaged hippocampus during surgery for epilepsy
irreversible damage to memory
localisation supported by real life evidence
W
disputing research
lateralisation patterns shift w/ age
clear differences between young/older brains
szaflarski et al
most tasks generally become less lateralised in healthy adulthood
need to take into account role of age/experiences
individual differences
herasty
women have proportionally larger wernickes/brocas areas
can explain language ease for women
differences between men and women are ignored
doesnt account for gender differences
research into plasticity
localisation of func is incorrect
shows that key areas for key functions can be changed after injuries/ functional recovery
simpler func likely to be localised
e.g motor control
sophisticated parts can swap/change if necessary
suggestions that the brain is localised is highly overstated