Hemispheric Lateralisation

Question 1

who conducted the split brain cat study

Answer 1

Myers and Sperry 1953

Question 2

what was cut in the brains of the cats in Myers and Sherry’s 1953 study

Answer 2

Optic chiasm and corpus callosum

Question 3

what is lateralisation

Answer 3

unequal representation of various psychological features. some functions are more dominant in certain hemispheres

Question 4

what is aphasia

Answer 4

a deficit in language comprehension due to damage in LH

Question 5

what is a type of aphasia

Answer 5

Brocas aphasia - speech production

Question 6

what is apraxia

Answer 6

difficulty performing movements on command

Question 7

who found that damage in the motor cortex leads to apraxia

Answer 7

Liepman 1900

Question 8

what did the discovery of apraxia lead to

Answer 8

hemispheric dominance

Question 9

what did Myers and Sperry 1953 find in their split brain study

Answer 9

the split brain cat group learned the task in just one hemisphere

Question 10

what can be concluded from Myers and sperrys 1953 study

Answer 10

both hemispheres aren’t needed for certain tasks

Question 11

what are 3 tests of cerebral laterality

Answer 11

WADA test, dichotic listening test, fmri

Question 12

who discovered the wada test

Answer 12

wada, 1949

Question 13

what does the wada test involve

Answer 13

temporarily numbing one hemisphere by injecting sodium amytal into that hemisphere and then asking the ppt to recall info, follow commands etc

Question 14

what happens when the LH is numbed in the Wada test

Answer 14

difficulty in speech production and comprehension - broca and wernicke

Question 15

what are 3 limitations of the Wada test

Answer 15

distressing, invasive, human error

Question 16

what does fmri measure

Answer 16

blood flow and oxygenation

Question 17

what are 3 limitations of fmri

Answer 17

metal = cant do it
expensive
unreliable - temporal accuracy 4s

Question 18

what is the procedure for the DLT

Answer 18

2 different signals (words etc) presented in both ears simultaneously

ppts asked to report what they heard

Question 19

who found that there is a right ear advantage in DLT

Answer 19

Kimura, 2011

Question 20

2 strengths of DLT

Answer 20

quick and affordable
convergent validity - measures HL

Question 21

who compared the accuracy of the Wada test and fmri from a meta analysis

Answer 21

Bauer, 2014

Question 22

what did Bauer 2014 find from his meta analysis

Answer 22

94% accuracy in typical cases
51% accuracy in atypical cases
consistent in determining laterality

Question 23

who found that DLT is only effective at detecting LH dominance but not RH dominance

Answer 23

Strauss, 1987

Question 24

what did Strauss 1987 do in the study

Answer 24

ppts already did Wada test
later tested on DLT

Question 25

how does fmri and DLT differ in their findings

Answer 25

DLT is effective for identifying LH dominance but less effective in atypical cases FMri clinically preferred as it provides a detailed measure for atypical cases

Question 26

who found that there isn't a definite dominance pattern as some RH features can contribute to LH functioning

Answer 26

Krietewolf 2014

Question 27

what did Krietewolf 2014 find about RH and LH

Answer 27

RH can contributing to language functioning through word meanings and emotional tones LH can contribute to spatial functioning through fine motor control for writing

Question 28

what is an example of anatomical asymmetry in the brain

Answer 28

Planum temporale / Wernickes area bigger in the LH

Question 29

what are 3 theories of the evolution of lateralisation

Answer 29

analytic-synthetic theory motor theory linguistic theory

Question 30

what are some limitations of the analytic-synthetic theory

Answer 30

oversimplifies brain function modern neuroscience suggests both hemispheres work together

Question 31

what does the motor theory say

Answer 31

The LH is dominant in fine motor control which is why it is also specialised in speech and language formation eg mouth movement and hand gestures

Question 32

what is a limitation of the motor theory

Answer 32

speech and language is more than just motor movement - cognition?

Question 33

what is the linguistic theory

Answer 33

LH is specialised in linguistic abilities like speech production, comprehension, and grammar. sign language users with LH damage lose their ability to sign but RH damage can still perform linguistic functions

Question 34

what are some limitations of the linguistic theory

Answer 34

not all linguistic functions are LH Atypical cases?