localisation of function in the brain Flashcards
what is the holistic theory
scientists generally supported the holistic theory of the brain
- all parts of the brain were involved in the processing of thought and action
what is the localisation theory
in contrast Broca and Wernickle argued for localisation of function( referred to as cortical specialisation sometimes)
this is that the brain performs different tasks and are involved with different parts of the body
It therefore follows that if a certain areas of the brain becomes damaged through illness or injury, the function associated with that area will also be affected
what is the brain divided into
the brain is divided into two symmetrical halves
the left and right hemispheres
what is lateralisation
some of our physical and psychological functions are controlled or dominated by a particular hemisphere
what is activity on the left hand side of the body controlled by
activity on the left hand side of the body is controlled by the right hemisphere
what is activity on the right hand side of the body controlled by
activity on the right hand side of the body is controlled by the left hemisphere
what is the cerebral cortex
the outer layer of both hemispheres is the cerebral cortex (or cortex)
it is 3mm thick and is what separates us from other animals because the human cerebral cortex is more developed
how does the cortex physical appearance
the cortex appears grey scale to the location of cell bodies
hence the phrase- “grey matter” to describe the surface appearance of the brain
what is the cortex of both hemispheres divided into
the cortex of both hemispheres is sub- divided into four lobes which are names after the bones beneath lie:
- the frontal lobe
- the parietal lobe
- occipital lobe
- temporal lobe
each lobe is associated with different functions
what is the function of the frontal lobe
at the back of the frontal lobe ( in both hemispheres) is the motor area which controls voluntary movement in the opposite side of the body
what happens when you damage the back of the frontal lobe
damage to this area may result in a loss of control over fine movements
what does the front of both parietal lobes do
the front of the parietal lobes is the somatosensory area which is separated from the motor area by a “valley”called the central sulcus
This is where the sensory info from the skin (too much heat e.t.c.) is represented
what does the amount of somatosensory area devoted to a particular body part denote
the amount of somatosensory area devoted to a particular body part denotes its sensitivity
e.g. receptors for our face and hands occupy over half of the somatosensory area
what does the occipital lobe at the back of the brain do
the occipital lobe at the back of the brain is the visual area/ visual cortex
each eye sends info from the right visual field to the left visual cortex and from the left visual field to the right visual cortex
what does damage to the occiptial lobe do
damage to the left hemisphere can lead to blindness to the right visual field of both eyes
what does the temporal lobes do
the temporal lobes houses the auditory area, which analyses speech - based info
what happens when the temporal lobes are damaged
damage may produce partial hearing
the more extensive the damage, the more extensive the loss
damage too specific area of the temporal lobe -“Wernickle’s area” may affect the ability to comprehend language
where is the language area of the brain
language is restricted to the left side of the brain in most people
what did Paul Broca identify in 1880s
in the 1880s Paul Broca identified a small area the left frontal lobe responsible for speech production
damage to this area causes Broca’s aphasia which is characterised bu speech that is slow, laborious and lacking fluency
e.g. Broca’s patients like “Tan” - Tan being the only word he could say
what did Karl Wernickle identify in his patients
Karl Wernicke was describing patients who had o problem producing language but severe difficulties understanding it
e.g. speech produced was fluent but meaningless Wernicke identified a region (Wernicke’s area) in the left temporal lobe as being responsible for language comprehension which would result in Wernicke’s aphasia when damaged
what does damage to Wernicke’s area result in
Wernicke’s aphasia
patients with this will often produce nonsense words (neologisms) as part of the content of their speech
