Hemispheric lateralisation

Question 1

how many participants were in sperrys study?

Answer 1

11 split brain patients

Question 2

what was procedure 1 of sperrys research- describing what you see

Answer 2

the participant was shown an object to their right visual field and asked to describe it.

they were then shown an object to their left visual field and asked to describe it

Question 3

what were the findings of sperrys procedure 1 - describe what you see

Answer 3

the ps could describe objects shown to their right visual field because they use language processing in their left hemisphere.

they couldnt describe objects shown to their left visual field and reported there was nothing there

Question 4

what was sperrys procedure 2 ?
recognition by touch

Answer 4

objects were placed behind a screen so that the patient could not see them

patients were then shown an object to either the left or right visual field

Question 5

what were the results of sperrys procedure 2?

Answer 5

When an object was presented to the left visual field they could not describe it but could select matching object from behind the screen

Question 6

what was sperrys procedure 3 ?

Answer 6

ps were shown 2 words simultaneously one on either side of the visual field

Question 7

what were the results of sperrys procedure 3 ?

Answer 7

the p would write the word from the left visual field with their left hand

say the word from their right visual field

e.g key and ring

write key
say ring

Question 8

what was sperrys procedure 4 - mathcing faces

Answer 8

a composite picture of 2 faces was shown

ps had to select the picture they saw from a line up

Question 9

what were the results of sperrys procedure 4 ?

Answer 9

the patients selected the face that was presented to their left visual field (right hem processed it )

picture presented to right visual field was ignored

Question 10

what did sperry conclude were the functions of left hem?

Answer 10

controls speech

production and language

logical thinking

numeracy

Question 11

what did sperry conclude were the functions of right hem?

Answer 11

controls facial recognition

empathy

hunour

Question 12

what is a positive of sperrys research -control

Answer 12

high control

ps were given eye patches and images were shown for a very brief amount of time

this makes sure that there was no possibility of ps looking over and using their other visual field

this strengthens the internal validity of the study

Question 13

what are the + of sperry

Answer 13

support from other researchers

high control

Question 14

who supports sperry ?

Answer 14

broca

both suggest that language is lateralised to the left hemisphere

Question 15

what are the negatives of sperry ?

Answer 15

quasi experiment

external validity

population validity

Question 16

how does sperry have poor validity?

Answer 16

small sample size makes it hard to generalise to other people and the task was unrealistic to real life

we dont have a stimulus presented to just one hemisphere irl

split brain procedure is rarely carried out now, meaning that patients are difficult to come by

most research has few ps and often the research takes an idiographic approach

any conclusions drawn could only be representative of those who had a physical disorder that resulted in the need for a split brain procedure
cant be generalised to wider population

Question 17

quais experiemtn - sperry -ve

Answer 17

the group of ps are already predetermined ( split brain patients ) means its more difficult to establish cause and effect

Question 18

what is the main advantage of brain lateralisation?

Answer 18

increases neural processing capacity (perform multiple tasks simultaneously )

Question 19

rogers et al

Answer 19

found that in dometic chicken, brain lateralisation is associated with an enhansed ability to perform 2 tasks at once (finding food and being vigilant)

using only one hemipshere to engage in a task leaves the other one free to do other functions

this provides evidence for the advantages of brain lateralisation and demonstrates how it can enhance brain efficiency in cognitive tasks

Question 20

what is the weakness of rogers et al

Answer 20

because the research wss carried out on animals it is impossible to conclude the same of humans

Question 21

what is the weakness of research into lateralisation?

Answer 21

split brain procedure is rarely carried out now, meaning that patients are difficult to come by

most research has few ps and often the research takes an idiographic approach

any conclusions drawn could only be representative of those who had a physical disorder that resulted in the need for a split brain procedure
cant be generalised to wider population

Question 22

research suggests that lateralisation changes with age- szaflarki et al

Answer 22

found that langauge became more lateralised to the left hemisphere with increasing age in children and adolescents

but after the age of 25 lateralisation decreased with each decade of life

this raises questions about lateralisation such as whether everyone has a dominant hemisphere and whether this dominance changes with age

Question 23

turk et als argument

Answer 23

it could be argued that language may not be restricted to the left hemisphere

turk et al discovered a patient who suffered damage to the left hemipshere but developed the capacity to speak in the right hemisphere

this eventually led to the ability to speak about the information presented to either side of the brain

suggests that lateralisation isnt fixed and that the brain can adapt following damage to certain areas