localisation of function in the brain

Question 1

localisation of function

Answer 1

the theory that different areas of the brain are responsible for different behaviours, processes and activities

Question 2

localisation versus holistic theory

Answer 2

scientists such as Broca and Wernicke discovered that specific areas of the brain are associated with particular physical and psychological functions
-before this scientists generally supported the holistic theory of the brain-that all parts of the brain were involved in the processing of thought and action

Question 3

hemispheres of the brain

Answer 3

the brain is divided into two symmetrical halves, left and right

• some of our physical and psychological functions are controlled by a particular hemisphere- this is called lateralisation
• activity on the left side of the body is controlled by the right hemisphere and visa versa

Question 4

cerebral cortex

Answer 4

the outer layer of both hemispheres is the cerebral cortex

Question 5

the motor, somatosensory, visual and auditory centres

Answer 5

the cortex of both hemispheres is sub-divided into four lobes which are mams after the bones beneath which they lie: frontal lobe, parietal lobe, occipital lobe and temporal lobe

Question 6

motor area

Answer 6

at the back of the frontal lobe is the motor area

• controls voluntary movement in the opposite side of the body
• damage to this area of the brain may result in a loss of control over fine movements
• regulates movement

Question 7

somatosensory area

Answer 7

front of parietal lobes

-processes sensory information such as touch

Question 8

visual area

Answer 8

occipital lobe at the back of the brain

• receives and processes visual information
• each eye sends information from the right visual field to left visual cortex 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

Question 9

auditory area

Answer 9

temporal lobes

• analyses speech based information
• damage may produce hearing loss or affect ability to comprehend language

Question 10

Broca’s area

Answer 10

area of the frontal lobe in the left hemisphere responsible for speech production

• in the 1880s, Broca identified a small area in the left frontal lobe responsible for speech production
• damage to broca’s area causes broca’s aphasia which is characterised by speech that is slow, laborious and lacking in fluency

Question 11

Wernickes area

Answer 11

area of the temporal lobe in the left hemisphere responsible for language comprehension
-wernicke identified a region in the left temporal lobe as being responsible for language comprehension which would result in wernickes aphasia when damaged (producing nonsense words)

Question 12

brain scan evidence of localisation

Answer 12

Peterson (1988)- used brain scans to demonstrate how wernickes area was active during a listening task and broca’s was active during a reading task

Tulving (1994)- revealed that semantic and episodic memories reside in different parts of the prefrontal cortex, there now exists a number of highly sophisticated and objective methods for measuring activity in the brain which show evidence of localisation

Question 13

neurosurgical evidence

Answer 13

the practise of surgically removing or destroying areas of the brain to control aspects of behaviour was developed in the 1950s

• Freeman developed the lobotomy which involved severing connections in the frontal lobe in an attempt to control aggressive behaviour
• neurosurgery is still used today, Dougherty (2002) reported on 44 OCD patients who had undergone a neurosurgical procedure, after 32 weeks a third had met the criteria for successful response and 14% for partial response

Question 14

case study evidence

Answer 14

Phineas Gage

• metre length pole through his left cheek, behind his left eye and out his skull-took our most of his left frontal lobe
• survived damage to his brain
• altered his personality- suggests that the frontal lobe may be responsible for regulating mood

Question 15

lashleys research

Answer 15

Lashley (1950)- suggests that higher cognitive functions such as the processes involved in learning are not localised but distributed in a more holistic way in the brain

• removed 10-50% of the cortex in rats learning a maze, no area was proven to be more important than any other in terms of the rats ability to learn the maze
• suggests learning is too complex to be localised and requires the involvement of the whole brain

Question 16

plasticity

Answer 16

when the brain has become damaged and a particular function has been compromised or lost, the rest of the brain appears able to reorganise itself in an attempt to recover