Localisation Of Function Flashcards
What is localisation of function and what was believed before the 19th century
Specific functions of the brain have specific locations in the brain, believed holistic theory that all parts of brain involved in processing all thought and action
What is the cerebral cortex
Outer layer of both hemispheres of the brain, separates humans from other animals as cortex developed, appears grey (grey matter)
Where is the motor cortex and what does it do
In frontal lobe near border with parietal lobe of both hemispheres, controls voluntary movement on opposite sides of body
What and where is the somatosensory cortex
In parietal lobe near border with frontal lobe, where sensory info from skin is represented. The amount of somatosensory area devoted to particular body part denotes its sensitivity
What is the somatosensory area separated from the motor area by
A valley called the central sulcus
Where is the visual area
In the occipital lobe at the back of the brain, each eye sends info from right visual field to left visual cortex and vise versa
Where is the auditory area
The temporal lobe which analyses speech based info, damage may produce partial hearing loss
Where is Broca’s area and what does it do and case study support
Left frontal lobe, speech production, patient called Tan had damage to this area and could only say his name
What is wernickes area
In left temporal lobe that controls speech comprehension, those with wernickes aphasia produce nonsense words
Expand on strength that there is brain scan evidence of localisation
-petersen et al used to brain scans to demonstrate how wernickes area was active during a listening task and brocas area active during a reading tasks, suggests these areas of the brain have different functions
-Tulving et al found semantic and episodic memories reside in dif parts of the PFC
-objective methods for measuring activity in brain= sound scientific evidence
Expand on strength that there is evidence from case studies and however point
-eg Phineas Gage had damage to frontal lobe which resulted in personality change but he could still walk and talk
-suggests different areas responsible for dif functions which disputes holistic theory
H: idiographic- difficult to generalise to rest of population
Expand on limitation that there is evidence to suggest higher cognitive functions are holistically distributed
-Lashley removed areas of the cortex (10-50%) in rats that were learning a maze
-no area was proven to be more important than any other area in terms of the rats’ ability to learn the maze, process of learning appeared to require every part of the cortex rather than being confined to a particular area
-suggests learning is too complex to be localised and requires involvement of whole brain
Expand on limitation that plasticity goes against notion of localisation
-when brain has been damaged and a particular function has been compromised/lost the rest of the brain appears able to reorganise itself in an attempt to recover the lost function
-Lashley described this as law of equipotentiality whereby surviving brain circuits chip in so same action can be achieved
-several documented cases of this, found effects of brain damage due to extent rather than localisation
