Research Into Lateralisation

Question 1

What is hemispheric lateralisation?

Answer 1

The idea that the two halves of the brain are functionally different.

Question 2

What is split brain research?

Answer 2

A series of studies which involved people with epilepsy who had experienced a surgical separation of the hemispheres.

Question 3

What is the corpus collosum?

Answer 3

What connects the left and right hemispheres of the brain.

Question 4

How are sensory and motor control processed?

Answer 4

Contralaterally

Question 5

What does contralaterally mean?

Answer 5

Opposite side
damage to the left hemisphere will affect the right side of the body, (vis versa)

Question 6

What is the procedure called when they cut the corpus collosum?

Answer 6

Hemispheric disconnection.

Question 7

What side of the brain is the left visual field connected to?

Answer 7

Right hemisphere.

Question 8

What side of the brain is the right visual field connected to?

Answer 8

Left hemisphere.

Question 9

What year was Roger Sperry’s research done in?

Answer 9

1968

Question 10

What was Sperry’s method?

Answer 10

An image/ word is projected to either visual field and processed by the certain hemisphere

Question 11

What did Sperry find?

Answer 11

That information presented to one hemisphere in split brain patients, it is not transferred to the other hemisphere.

Question 12

What were the 3 tasks Sperry and Gazzaniga tested in split brain patients?

Answer 12

1) describe what you see
2) tactile test
3) drawing task

Question 13

What did the do in the describe what you see task?

Answer 13

An image was presented to either the left or right visual field and they had to describe what they saw.

Question 14

What did they do in the tactile test task?

Answer 14

An object was placed in the patients left or right hand and they had to describe what they felt or select a similar object from a series.

Question 15

What did they do in the drawing task?

Answer 15

Participants were presented with an picture in either their left or right visual field, and they had to draw what they see

Question 16

Describe what you see findings?

Answer 16

When picture was presented to the LVF they could describe what they saw, but when it was presented to the RVF they could not describe what they saw.

Question 17

Tactile test findings?

Answer 17

When object was placed in right hand (LH) they could describe what they felt, but when the object was put in their left hand (RH) they could not describe what they felt

Question 18

Drawing task findings?

Answer 18

When the picture was presented to the right visual field (LH) the picture they drew was never clear, but when the picture was presented to the left visual field (RH) they drew much clearer and better pictures.

Question 19

What is the left hemisphere dominant in?

Answer 19

Speech and language.

Question 20

What is the right hemisphere dominant in?

Answer 20

Visual-motor tasks.

Question 21

What year was Sperry and Gazzaniga research done in?

Answer 21

1967

Question 22

How many patients were in Sperry’s study?

Answer 22

11

Question 23

Strength - Chicken study + counterpoint

Answer 23

• it is assumed that lateralisation increases neural processing capacity
• Rogers et al found in domestic chickens that brain lateralisation enhanced the ability to perform two task simultaneously
• can enhance brain efficiency
• (C) study was on animals not humans + not many split brain patients

Question 24

Weakness - age

Answer 24

• research shows that lateralisation changed with age
• Szaflarki et al (2006) found that language became more lateralised to the LH with age, but after 25 lateralisation decreased
• this raises questions, like whether everyone has a hemisphere more dominant and whether this changes with age

Question 25

Critisism - language may not be restricted to LH

Answer 25

• Turk et al (2002) discovered a patient who damaged LH, but developed the capacity to speak in the RH
• this suggest that lateralisation may not be fixed but that the brain can adapt following damage.

Question 26

Limitation - split brain procedure is rarely carried out nowadays + counterargument

Answer 26

• Andrews points out that there are not many participants, patients may have other confounding physical disorders, or have less sectioning than originally believed
• (C) despite small sample size, studies are in a lot of detail, allows researcher to investigate in a lot more detail

Question 27

Lateralisation meaning?

Answer 27

One hemisphere of the brain being responsible for particular physical and psychological functions.