Biopsych- Hemispheric lateralisation

Question 1

What is Hemispheric lateralisation?

Answer 1

Thee idea that halves of the brain are functionally different and that each hemisphere has functional specialisations, the left is dominant for language and the right excels at visual motor tasks

Question 2

What are the functions of the left hemisphere?

Answer 2

-Langauge centre
-Controls right hand side of the body
-Receives info from the right visual field

Question 3

What are the functions of the right hemisphere?

Answer 3

-Focusses on visual and motor tasks
-Controls left handd side of the body
-Receives info from the left visual field

Question 4

What is the corpus collosum ?

Answer 4

Two hemispheres are connected by nerve fibers
-Facilloitate interhemispheric communication
-Allowing the left and right hemispheres to communicate

Question 5

What did Sperry and gaziniga invcestigate?

Answer 5

-1st people to investigate Hemispheric lateralisation with the use of split brain patients
-Split brain patients are individuals who have undergone a commissurotomy (their corpus collusm has been severed)

Question 6

What was the aim of Sperry and gazingas research?

Answer 6

To examine the extent to which the two hemispheres are specialized for certain functions

Question 7

Describe what you see: Picture presented to the left visual field (processed by right visual field)

Answer 7

-If a picture was presented to the LVF the patient could not describe what was shown and often reported that nothing was present

Question 8

Describe what you see: Picture presented to the right visual field (processed by left visual field)

Answer 8

-If a picture was presented to the RVF the patient could describe what they say
-Langage is dominant in the left hemisphere

Question 9

Tactile tests: objects placed in the left hand (processed by the right hemisphere)

Answer 9

-The patient could not describe what they felt and could only make wild guesses

Question 10

Tactile tests:Objects placed in the right hand (processed by the left hemisphere)

Answer 10

-The patient could describe verbally what they felt

Question 11

Drawing tests: Picture being drawn using left hand (processed by the right hemisphere)

Answer 11

-Consistently drew better+ clearer pictures than the right hand even if they were right handed
-Demonstaretes the superiority of the right hemisphere when it comes to visual motor tasks

Question 12

Drawing tests: Picture being drawn using right hand (processed by the right hemisphere)

Answer 12

-Not as clear as the left hand

Question 13

Give an advantage of Hemispheric lateralisation (Multitasking)

Answer 13

-One of the main advantages of brain lateralisation is that it increases neural processing capacity (or the ability to multitask)
-Rogers et al found that in domestic chicken, brain lateralisation is associated with an enhanced ability to perform to tasks simultaneously (finding food and being vigilant for predators)
-Using only one hemisphere to engage in a task leaves the other hemisphere free to engage in other functions
-Although we cannot generealise findings from animals (especially from birds) to humans
-We also do not need to find food and be vigilant for predators as it is not the stone age so therefore not relevant to today
-Providees eviedence for the advantages of brain lateralisation and demonstrates how it can enhance brain efficiency in cognitive tasks

Question 14

Give an evaluation point (language in the right hemisphere)

Answer 14

-Langauge many not be ristricted to the left hemisphere
-Turk et al discovered patient J.W that suffered damage to the left hemisphere but developed the capacity to speak in the right hemisphere eventually leading to the ability to speak about the information presented to either side of the brain
_however this takes takes an idiographic approach as it only studies one person so cannot generalist the findings
-Matters because it suggests that perhaps lateralisation is not fixed and that brains can adapt following damage to certain areas

Question 15

Give an evaluation point (Small sample)

Answer 15

-Futhermore there are several methodological criticisms of split brain paaitents
-Sample consisted of 11 peoplee
-Sperry and Gaziniga had a very small sample
-the individuals may have had difficulties before surgery, individual differences can’t gerenerealise
-However there re very few individuals that have had their corpus collusm severed so they have been very useful in explaining Hemispheric lateralisations
-The findings have been applied to treating people who have damage to their right and left hemisphere

Question 16

Give an evaluation point (nature of the brain)

Answer 16

-There is a debate over the nature of the brain
-Sperrys work triggered debate about the nature of consciousness and the degree of communication between the two hemispheres in everyday functioning
-Ducetti suggested that hemispheres are so functionally different they represent a form of duality in the brain
-Others argued the 2 hemispheres are highly integrated and work together