Localisation + Split Brain

Question 1

What is localisation of function in the brain?

Answer 1

-theory that different areas of the brain are responsible for specific behaviours

Question 2

What is the motor area?

Answer 2

-region involved in regulating movement

Question 3

What is the somatosensory area?

Answer 3

-processes info associated with senses

Question 4

What is the visual area?

Answer 4

-responsible for processing visual information

Question 5

What is the auditory area?

Answer 5

-responsible for processing auditory info + speech
-in temporal lobe
-more extensive damage = more extensive loss

Question 6

What is cerebral cortex?

Answer 6

-outer layers surrounding brain

Question 7

Where is language restricted to?

Answer 7

-left side (lateralised)

Question 8

What is Broca’s area?

Answer 8

-responsible for speech production

Question 9

What is aphasia?

Answer 9

-difficulty forming complete or understanding sentences

Question 10

What is Wernicke’s area?

Answer 10

-responsible for language understanding

Question 11

Supporting evidence for localisation

Answer 11

-Tulving - PET scans
-semantic recalled from left prefrontal
-episodic recalled from right prefrontal
-different areas responsible for different functions

Question 12

Further support for localisation

Answer 12

-Peterson
-activation in Wernicke’s area in listening
-Broca’s activated in reading
-confirms their study’s

Question 13

Supporting case study

Answer 13

-Phineas Gage - injured by blasting rod into left side of face
-went through prefrontal cortex
-caused defect in rational decision making
-areas of brain responsible for specific behaviours

Question 14

What is a contradiction to localisation?

Answer 14

-holistic view of brain function
-each function requires several areas to be activated and not just restricted to these areas

Question 15

Contradiction to Holism - Rat study

Answer 15

-removing 20-50% of cortices
-no specific area associated with learning how to traverse through a maze
-intelligence is too complex and advanced a cognitive ability to be restricted to certain areas

Question 16

Support link between areas + OCD

Answer 16

-Dougherty - 44 people with OCD who’d undergone cingulotomy
-32 mths after - 30% met successful responses
-14% partial response
-improved understanding of localisation has practical applications in development of advanced treatments for mental disorders

Question 17

What is hemispheric lateralisation?

Answer 17

-each hemisphere is mainly responsible for certain behaviours, processes and activities

Question 18

Is language lateralised?

Answer 18

-yes - in left hemisphere

Question 19

Cross wiring

Answer 19

-contralateral wiring

Question 20

Vision

Answer 20

-contralateral + ipsilateral

Question 21

Sperry & Gazzaniga

Answer 21

-split brain research on 11 ppl with epilepsy
-underwent surgical lesion in of corpus callosum
-aim to expose single hemisphere to certain stimuli in SP patients - infer functions

Question 22

What was the method of Sperry’s study?

Answer 22

-one eye covered
-stimuli flashed on screen
-prevented both VF of eyes being exposed to info

Question 23

Sperry - describing what you see

Answer 23

-stimulus word exposed to RVF
-processed by LH - say the word
-if stimulus exposed to LVF
-processed by RH - would write the word

Question 24

Sperry - matching words or faces

Answer 24

-RH dominates ability to match list of faces to given stimulus
-RH contains VS centres
-allows visual identification and processing of faces

Question 25

Sperry - words presented simultaneously

Answer 25

-2 words present at same time to each VF
-patient would say word on RVF
-write down word presented to LVF

Question 26

Sperry -recognising objects placed in hands

Answer 26

-object in right hand - unable to identify its there
-info would be processed by LH - only has language centres
-object in left hand - identify object and choose similar one from bag

Question 27

What is a negative of Sperry’s study?

Answer 27

-epileptic patients had been taking medications for extended periods of time - may have affected their ability to recognise objects + match words
-may be differences in the exact procedure each patient had
-lateralisation may be examples of unreliable casual conclusions

Question 28

What is support for lateralisation?

Answer 28

-pivotal in establishing differences in functions between 2 hemispheres
-lots of evidence to support LH = language and RH = synthesises info
-standardised + well controlled procedures - ensures only 1 hemisphere was receiving = replicability

Question 29

What is a contradiction to spilt brain research?

Answer 29

-led to research that oversimplifies + overemphasises the functional distinction
-research into neural plasticity demonstrates functions associated with 1 H could be performed by the other = make sure we don’t oversimplify complex functions

Question 30

What is a contradiction to split brain research?

Answer 30

-Left responsible for language and right for synthesising - giving a false impression that are are ‘opposite’ in function
-Pucetti - cases of split brain who are left handed but produce speech in RH - opposes lateralisation theory
-important not to jump to conclusions
-appreciate that each H is not restricted to specific functions

Question 31

A03 - Supporting evidence to lateralisation

Answer 31

P = supporting evidence from phineas gage study
E = he experienced huge changes to personality as a result of damage to the left frontal lobe
E = before the accident he was calm + reserved, after the accident he was hostile + quick tempered
L = this demonstrates that there are localised areas of the brain as the area gage damaged links to reasoning, control and mood

Question 32

A03 - critique to lateralisation

Answer 32

P = limitation - based on small + unique sample
E = Gage survived a metre long tamping iron passing through skull
E = therefore, we can’t be sure if the brain works according to this theory in all individuals
L = however a number of objective studies also demonstrate localisation of brain function
eg. Tulving demonstrated episodic + semantic memories reside in different areas of the prefrontal cortex

Question 33

A03 - Opposing research to localisation

Answer 33

P= opposing research from Maguire
E= she analysed london taxi drivers brains compared to control subjects who did not drive taxis
E= MRI scans showed hippocampal volume was larger in taxi drivers due to high dependence on spatial navigation skills
L= incomplete explanation as can’t account for fact that brains can develop differently depending on use

Question 34

A03 - Alternative explanation to localisation

Answer 34

P= further argument is notion of functional recovery
E= following an injury the brain is able to rewire and reorganise itself in order to recover lost function, this can involve another part of brain taking over that function
E= illustrated by Jodie Miller who had hemispherectomy almost all her right hemisphere removed, she was able to walk within 10 days
L= Suggests localisation is not fixed to specific areas for specific function; functional recovery supports holistic theory suggesting the brain is working as whole unit

Question 35

A03 - Practical application of localisation

Answer 35

P= application to real life behavior
E = brain scanning methods shown that increased activity in orbitofrontal cortex may explain obsessive thoughts as this part of brain involved in cog processing of decision making
E = has also been revealed increased activity in basal ganglia may explain compulsions as this part of brain initiates motor functions
L = strength as brain scanning methods can help diagnose OCD, these individuals can receive treatment helping increase QOL