Lateralisation

Question 1

What is lateralisation?

Answer 1

Each hemisphere has a specific function

Question 2

How does info travel from one hemisphere to the other?

Answer 2

• they’re connected by corpus callosum

- info moves across as signals

Question 3

Who did the key research for lateralisation?

Answer 3

Sperry (1968) - split brain research

Question 4

What p’s did Sperry use?

Answer 4

• had surgery
• corpus collosum was cut
• this was to separate hemispheres
• attempt to treat epilepsy

Question 5

What did Sperry look into?

Answer 5

• info from left visual field goes to right hemisphere
• info from right visual field goes to left hemisphere
• if corpus collosum was cut info shouldn’t travel over

Question 6

What is the procedure of Sperry’s research?

Answer 6

• p’s focus on a dot in middle of visual field
• info was presented on different sides of field
• p’s asked to respond:
• with left hand
• with right hand
• verbally
• control group also used

Question 7

What were the results of sperry’s research when p’s had to describe what they’ve seen?

Answer 7

• a word in right visual field was immediately reported
• unaware of word in left visual field
• left hemisphere = Lang

Question 8

What were the results of Sperry’s research for recognition by touch?

Answer 8

• if word in right hemisphere, left hand could choose correct hidden object
• when asking why holding object they couldn’t answer
• right hemisphere has some basic Lang abilities

Question 9

What were the results of Sperry’s research for matching faces?

Answer 9

• faces in left visual field constantly choose
• faces in right visual field ignored
• when a face of 2 halves shown:
• left hemisphere = verbal description
• right hemisphere = matching picture

Question 10

What are the strengths of Sperry’s solid brain research?

Answer 10

• supporting research

- methodology

Question 11

What is the supporting research for Sperry’s split brain research

Answer 11

• Rasmussen and Milner (1977)
• found left hem = languages
• right hem = artistic functioning
• ornstein (1986)
• right side = creative side
• left side = logic
• supports lateralisation

Question 12

How is methodology a strength of Sperry’s split brain research?

Answer 12

• high levels of control
• to stop p’s moving their eyes to see image on other side
• image only shown for 200 milliseconds
• testing what it should test

Question 13

What is the counter evaluation to the methodology strength of Sperry’s research?

Answer 13

• lack of ecological validity
• doesn’t reflect the brain in everyday life
• we would usually use both eyes
• limits generalisation

Question 14

What are the limitations of Sperry’s split brain research?

Answer 14

• population validity

- counter evidence

Question 15

How does Sperry’s research lack population validity?

Answer 15

• 11 males studied
• in some smaller pathways that connect hemispheres was cut aswell
• p differences
• can’t generalise

Question 16

What is the counter evidence of Sperry’s research?

Answer 16

• Turk (2002)
• studied JW who developed the ability to speak using right hem
• can now talk about info in both left and right visual field
• plasticity