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localisation of function in the brain - Coggle Diagram
localisation of function in the brain
evaluation
strengths
damage to areas of the brain has been linked to mental disorders
neurosurgery = last resort method for treating some mental disorders, targeting specific areas
a researcher found that 32 weeks after surgery, around 30% of patients had met the criteria for successful response to cingulotomy & 14% for partial response
cingulotomy = isolating the cingulate gyrus
this success suggests behaviours associated with serious mental disorders may be localised
evidence from brain scans supporting the idea that many everyday brain functions are localised
a researcher used brain scans to find that wernicke's area was active during a listening task, and broca's area in a reading one
this confirms localised areas for everyday behaviours
therefore, objective methods have provided good scientific evidence that many brain functions are localised
limitations
language may not be localised just to broca and wernicke's areas
research found only 2% of modern researchers think that language in the brain is completely controlled by these 2 areas
advances in brain imaging techniques mean neural processes can be studied with more clarity than ever before
seems it is distributed far more holistically than first thought, eg in thalamus
suggests language may be organised more holistically in the brain, contradicting localisation theory
(counterpoint to evidence from brain scans) - challenging evidence
a researcher found that no area was found to be more important than another in terms of rats' ability to learn a route after areas of the cortex were removed
learning appeared to require all areas of the cortex
suggests that higher cognitive processes, eg learning, aren't localised but instead distributed more holistically in the brain
the 4 brain areas
motor area
back of frontal lobe
controls voluntary movement on opposite side of body
damage = loss of control over fine movements
somatosensory area
front of both parietal lobes
is where sensory information from skin is represented
damage = decreased sensory thresholds
visual area
in occipital lobes
each eye sends information from right visual field to left visual cortex, & vice versa
damage = reduced vision in right field of both eyes, if occurred in left hemisphere
auditory area
in temporal lobes
analyses speech-based information
damage = reduced hearing or deafness
localisation vs holistic theory
localisation
= argued by broca & wernicke, the idea that different parts of the brain perform different tasks & are involved with different parts of the body - if a certain area becomes damaged, its function will also be affected
holistic theory
= all parts of the brain are involved in the processing of thought & action
competing theories
brain hemispheres
the main part of the brain (the cerebrum) is divided into 2 symmetrical halves: left hemisphere & right hemisphere
lateralisation
= some physical & psychological functions are controlled/dominated by a particular hemisphere
activity on left side of body is controlled by right hemisphere & vice versa
cerebral cortex = outer layer of both hemispheres
language centres of the brain
language is restricted to left side of the brain in most people
broca's area
small area in left frontal lobe
responsible for speech production
damage = broca's aphasia - slow, laborious speech
wernicke's area
small area in left temporal lobe
responsible for language understanding
damage = wernicke's aphasia - nonsense words (neologisms)
blue =
frontal lobe
yellow =
parietal lobe
green =
temporal lobe
pink =
occipital lobe
bottom =
cerebellum
- fine delicate movement, balance & dexterity
brain stem
= sends signals from your brain to the rest of your body & controls many subconscious body functions, such as breathing, heart rate & thirst/hunger
