Hemispheric lateralisation and split-brain research

Question 1

What does localisation refer to?

Answer 1

The fact that some functions, such as vision and language, are governed by very specific areas in the brain

Question 2

True/False: The brain is lateralised

Answer 2

True

Question 3

What are the two sides to the brain called?

Answer 3

Hemispheres

Question 4

True/False: There is evidence showing that even in connected brains the two hemispheres process information differently

Answer 4

True

Question 5

What did Fink et al. (1996) use PET scans for?

Answer 5

To identify which brain areas were active during a visual processing task

Question 6

What did Fink et al. (1996) find about participants with connected brains when they were asked to attend to global elements of an image e.g. looking at a picture of a whole forst?

Answer 6

Regions of the RH were much more active

Question 7

What did Fink et al. (1996) find about participants with connected brains were required to focus in on the finer detail of an image (such as individual trees)?

Answer 7

Specific areas of the LH tended to dominate

Question 8

What did Fink et al. (1996)’s findings show about hemispheric lateralisation in the connected brain?

Answer 8

At least as far as visual processing, it is a feature of the connected brain as well as the split-brain

Question 9

The brain being lateralised enables two tasks to be…

Answer 9

performed simultaneously with greater efficiency

Question 10

What did Rogers et al. (2004) show about lateralised chickens?

Answer 10

They could find food while watching for predators but ‘normal’ chickens couldn’t

Question 11

True/False: Neural plasticity means some functions can be taken over by non-specialised areas in the opposite hemisphere

Answer 11

True

Question 12

Why may functions be taken over by non-specialised areas in the opposite hemisphere of the brain?

Answer 12

As a result of damage through illness or trauma

Question 13

True/False: Holland et al. (1996) said that the language function was restricted to the left side of the brain

Answer 13

False, it cal literally ‘switch sides’

Question 14

Give an example of functions in which the localised areas appear in both hemispheres

Answer 14

In the case of vision, the visual area is in the left and right occipital lobe

Question 15

Where is the visual area located?

Answer 15

In the left and right occipital lobe, located in the left and right hemisphere respectively

Question 16

For most people, where are the two main centres for language?

Answer 16

Broca’s area - left frontal lobe, Wernicke’s area - left temporal lobe. Left hemisphere

Question 17

True/False: We can say language is lateralised

Answer 17

True

Question 18

What is meant by saying that language is lateralised?

Answer 18

It’s performed by one hemisphere rather than the other

Question 19

True/False: The RH can only produce rudimentary words and phrases

Answer 19

True

Question 20

What does the RH contribute towards what’s being said?

Answer 20

Emotional context

Question 21

The fact that the RH can only produce rudimentary words and phrases and contributes emotional context to what’s being said has led to the suggestion that…

Answer 21

the LH is the analyser whilst the RH is the synthesiser

Question 22

Why may the suggestion that the LH is the analyser and the RH is the synthesiser be wrong?

Answer 22

There may be different functions in the RH and LH

Question 23

What did Nielsen et al. (2013) analyse?

Answer 23

Brain scans from over 1000 people aged 7 to 20

Question 24

Nielsen et al. (2013) analysed brain scans from how many people of which age?

Answer 24

1000 people aged. 7to 20

Question 25

What did Nielsen et al. (2013) find when analysing the brain scans of 1000 people aged 7 to 20?

Answer 25

People use certain hemispheres for certain tasks (evidence for lateralisation) but there was no evidence of a dominant side

Question 26

True/False: Nielsen et al. (2013) found evidence for a dominant side of the brain

Answer 26

False, there was no evidence of a dominant side (e.g. artist's brain or mathematician's brain)

Question 27

What is meant by the vision, motor and somatosensory areas not being lateralised?

Answer 27

They appear in both hemispheres

Question 28

What is meant by contralateral wiring in the brain?

Answer 28

The brain is cross-wired - the RH controls movement on the left side of the body and vice versa

Question 29

Vision is simple/complex

Answer 29

complex

Question 30

True/False: Each eye receives light from the left and right visual fields

Answer 30

True

Question 31

The LVF of both eyes is connected to...

Answer 31

the RH

Question 32

The RVF of both eyes is connected to...

Answer 32

the LH

Question 33

Why is the LVF of both eyes connected to the RH and vice versa?

Answer 33

This enables the visual areas to compare the slightly different perspective from each eye and aids depth perception

Question 34

The LVF of both eyes is connected to the RH and vice versa. Why is there a similar arrangement to this for auditory input?

Answer 34

The disparity from the two inputs helps us locate the source of sounds

Question 35

What does a split-brain operation involve?

Answer 35

Severing the connections between the RH and LH, mainly the corpus callosum

Question 36

The split-brain operation involves severing the connections between the RH and LH, mainly the...

Answer 36

corpus callosum

Question 37

Why is the split-brain surgical procedure often carried out?

Answer 37

To reduce epilepsy

Question 38

During an epileptic seizure the brain experiences excessive electrical activity which travels from one hemisphere to the other. What can be done to reduce this?

Answer 38

The connections can be cut in order to 'split' the brain in two halves

Question 39

Sperry devised a system to study what?

Answer 39

How two separated hemispheres deal with information

Question 40

Who did Sperry study?

Answer 40

11 people who had a split-brain

Question 41

How many people with split brains did Sperry study?

Answer 41

11

Question 42

What was the setup of Sperry's study?

Answer 42

A spatial setup in which an image could be projected to a participant's RVF (processed by the LH) and the same, or different, image could be projected to the LVF (processed by the RH)

Question 43

What would happen if people with 'normal' brains were used in Sperry's study?

Answer 43

The corpus callosum would immediately share the information between both hemispheres giving a complete picture of the visual world

Question 44

What happened when presenting an image to one hemisphere of a split-brain participant in Sperry's study?

Answer 44

The information couldn't be conveyed from that hemisphere to the other. When an image was shown to a participant's RVF, they could describe what was seen

Question 45

What do Sperry's observations of split-brain patients show?

Answer 45

How certain functions are lateralised in the brain and support the view that the LH is verbal and the RH is 'silent' but emotional

Question 46

Why are causal relationships hard to establish in Sperry's study?

Answer 46

An issue is that none of the participants in the control group had epilepsy - this is a major confounding variable

Question 47

Why is the fact that none of the participants in Sperry's control group had epilepsy a major confounding variable?

Answer 47

Differences that were observed may be the result of the epilepsy rather than the split brain

Question 48

True/False: Fink's research challenges Sperry's conclusion

Answer 48

False, it supports Sperry's conflusion

Question 49

True/False: There is more recent brain research to support Sperry's conclusion

Answer 49

True, Luck et al. (1989)

Question 50

What did Luck et al. (1989) show about split-brain participants' performance in certain tasks?

Answer 50

They performed better than connected controls on certain tasks, e.g. they were faster at identifying the odd one out in an array of similar objects

Question 51

True/False: Luck et al. (189) found that split-brain patients performed better than connected controls at identifying the odd one out in an array of similar objects

Answer 51

True

Question 52

What did Kingstone et al. (1995) say about the normal brain's LH?

Answer 52

In the normal brain. the LH's better cognitive strategies are 'watered down' by the inferior RH

Question 53

Luck et al.'s findings that split-brain participants actually perform better than connected controls on certain tasks supports Sperry's findings that...

Answer 53

the 'left brain' and 'right brain' are distinct

Question 54

True/False: The split-brain operation was performed for the purpose of research

Answer 54

False, it was not

Question 55

In Sperry's split-brain research, what had to happen before the study could take place?

Answer 55

All procedures were explained and their full informed consent was obtained

Question 56

Why may there be questions regarding the ethicality of Sperry's split-brain research?

Answer 56

The trauma of the operation might mean that participants didn't later fully understand the implications of what they had agreed to

Question 57

True/False: Sperry's split-brain subjects were subject to repeated testing over a lengthy period

Answer 57

True

Question 58

What is the problem with Sperry's split-brain patients being subject to repeated testing over a lengthy period of time?

Answer 58

This may have been stressful for them

Question 59

What did participants in Sperry's study say when objects were shown to the LVF?

Answer 59

There was 'nothing there'

Question 60

Why did participants in Sperry's split-brain study say there was 'nothing there' when an object was shown to their LVF?

Answer 60

In the connected brain, messages from the LVF (RH) are relayed to the language centres in the LH - this is not possible in the split-brain

Question 61

Although participants couldn't give verbal labels to objects protected to the LVF, what could they do?

Answer 61

Select a matching object out of sight using their left hand

Question 62

Although participants couldn't give verbal labels to objects protected to the LVF, they could select a matching object using which hand?

Answer 62

Their left

Question 63

Why could participants use their left hand to point out an object closely associated with the object presented to their LVF, but not their right hand?

Answer 63

The RH is linked to the left side of the body

Question 64

Give an example of when the left hand was able to select an object that was most closely associated with an object presented to the LVF in Sperry's study

Answer 64

An ashtray was selected in response to a picture of a cigarette

Question 65

What happened if a pinup picture was shown to the LVF of participants in Sperry's study?

Answer 65

There was an emotional reaction (e.g. a giggle) but participants usually reported seeing nothing or just a flash of light

Question 66

What did participants report seeing after a pinup picture was shown to their LVF in Sperry's split-brain study?

Answer 66

Nothing or just a flash of light