Localisation of function in the brain

Localisation of function in the brain

KEY TERMS:Localisation of function - the theory that different areas of the brain are responsible for different behaviours, processes or activities.Motor area - A region of the frontal lobe involved in regulating movementSomatosensory area - An area of the parietal lobe that processes sensory information like touch.

Visual area - A part of the occipital lobe that receives and processes visual informationAuditory area - Located in the temporal lobe and concerned with the analysis of speech-based informationBroca's area - An area of the frontal lobe of the brain in the left hemisphere (in most people) responsible for speech production.Wernicke's area - an area of the temporal lobe (encircling the auditory cortex) in the left hemisphere (in most people) responsible for language comprehension

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Localisation vs holistic theory

19th Century - Broca and Wernicke found that different parts of the have different functions Before this, scientists thought every part of the brain was involved in processing thought and action If certain areas of the brain are damaged, the function associated with that area is also affected

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Brain hemispheres and the cerebral cortex

The brain's divided into the right and the left hemispheres Activity on the left-hand side of the body is controlled by the right hemisphere Activity on the right-hand side of the body is controlled by the left hemisphere The cerebral cortex is the outer layer of the hemispheres, it's about 3 mm thick and is much more developed than animals The cortex appears grey due to cell bodies location

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The motor and somatosensory centre

Motor area:- Back of the frontal lobe- Controls voluntary movement in opposite side of body- Damage could lead to loss of control over fine movements

Somatosensory area:- Front of both parietal lobes- Separated from the motor area by the central sulcus which is like a valley- Sensory information from the skin is represented- The higher the sensitivity of an area on our body, the larger the amount of somatosensory area it takes up

The visual and auditory centres

Visual area:- Occipital lobe at the back of our brain- Each eye sends information from the right visual field to the left visual- And from the left visual field to the right visual cortex- Damage to the left hemisphere, can produce blindness in part of the right visual field of both eyes

Auditory area:- Temporal lobes house the auditory area- Analyses speech-based information- Depending on the amount of damage, would result in hearing loss- Damage to Wernickes area mat affect ability to comprehend language

The language area of the brain

Language is restricted to the left side of the brainBroca (1880's) identified a small area of the left frontal lobe responsible for speech productionDamage to Broca's area causes Broca's aphasia - slow laborious, speech, lacking in fluency

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Cont. the language area of the brain

Wernicke desribed patients who had no problem producting language but struggled understanding itSpeech they produced was fluent but meaninglessWernicke found an area in the left temporal lobe as responsible for language comprehension

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EVALUATION

EVALUATION

EVALUATION