split brain research into hemispheric lateralisation

Question 1

hemispheric lateralisation is the idea that each hemisphere of the brain is responsible for certain behaviours , processes and activities , this in contrast with the

Answer 1

holistic theory of the brain function which suggests that function is distributed across the whole brain

Question 2

each visual field has two sides , left and right , the right hemisphere controls the

Answer 2

left side of the body and vice versa

Question 3

therefore information we receive from the left visual field is processed by the

Answer 3

right hemisphere , which then co ordinates a response to affect the left side of the body

Question 4

sperry and gazzangia 1968
conducted on split brain research on 11 epileptic patients , in order to control their seizures , these patients underwent

Answer 4

surgical lesioning of corpus callosum , through a procedure called cerebral commissurotomy , where information processed by one hemisphere cannot be relayed to the other
therefore possible to expose a single hemisphere to a single stimulus , and thus infer functions of each hemisphere

Question 5

sperry and gazzangia 1968
the patients had one of their eyes covered so that information would not be received by both eyes , the stimulus was flashed on screen for one tenth of a second preventing

Answer 5

both visual fields of the eye being exposed to the info , so that only one hemisphere would process it

Question 6

sperry and gazzangia 1968
strictly controlled conditions through the use of

Answer 6

lab experiments

Question 7

sperry and gazzangia 1968
describing what you see

Answer 7

stimulus word = right visual field , processed by left hemisphere , patient would say the word as left contains language centres
stimulus word = left visual field , processed by right hemisphere , patient would write the word with left hand , as right contains the visual spatial centres of the brain allowing for writing

Question 8

sperry and gazzangia 1968
matching words or faces

Answer 8

right hemisphere = dominated the ability to match a list of faces to a given stimulus , as contains the brains visuio spatial centres allowing for the visual identification of processing faces

Question 9

sperry and gazzangia 1968
words presented simultaneously

Answer 9

if two words presented at the same time each to one of the visual fields , patient would say the word presented to right visual field ,
and write down the word presented to the left visual field

Question 10

sperry and gazzangia 1968
recognising objects placed into hands

Answer 10

object placed into right patient’s hand = unable to identify as info would be processed by left hemisphere containing language centres
object placed into left patients hand = able to identify object and choose a similar one from a hidden bag due to the right hemisphere having visual spatial centres

Question 11

• lack of control with the sample selection
  the epileptic patients had been taken anti epilepsy medications for extended and different periods of time which may have effected their ability to recognise and match words due to causing curable neuronal changed adittionaly although all patients had undergone

Answer 11

a commissurotomy there may have been differences in exact procedures , ie what extent . this would have affected to a degree to which the two hemispheres could relay info between themselves
therefore two confounding variables had not been controlled , lateralised functions may be examples of unreliable conclusions

Question 12

• clearest dmeionstrated lateralisation of function
  split brain research was pivotal in establishing the differences in functions between the two hemispheres and so opposing the holistic theory of brain function , the left hemisphere was demonstrated as

Answer 12

being dominant for language tasks due to containing language centres whereas the right hemisphere was demonstrated as being dominant for visual spatial tasks
therefore this suggests the left hemisphere is the analyser and the right hemisphere is the synthesiser .

Question 13

• contribution to discussions about lateralisation theories
  such evidence strongly supported the idea of a dual mind , where two hemispheres represent two sides of the mind
  PUCETTI 1980. criticised

Answer 13

sperry and gazzangias work by pointing out that visual stimuli impinging on the half of each eyes retina do not go to the right , but to the left cereal hemisphere since the retina is concave and each half retina receives light from the contralateral side of the body
(In short, each half of the retina receives information from the opposite visual field, and the brain processes the signals in the opposite hemisphere.)
therefore it is clear that split brain research has sparked much debate about the physiological and theoretical basis of brain function