3.7. Lateralistion

Question 1

What are the hemispheres we have?

Answer 1

Left and right hemisphere

Question 2

What are the hemispheres connected by?

Answer 2

Corpus Callosum

Question 3

What is the Corpus Callosum

Answer 3

A bundle of fibres that allow communication between the 2 hemispheres

Question 4

What is the role of the right hemisphere?

Answer 4

The synthesiser
Responsible for creativity, facial recognition, awareness of places, objects and contextual perception
Controls left side of the body

Question 5

What is the role of the left hemisphere?

Answer 5

The analyser
Responsible for academics, speech and language, analysis, sequencing, recognition of names, words, numbers
Controls the right side of the body

Question 6

How does info get processed in the eyes?

Answer 6

If each eye, you have a right visual field and a left visual field
Information from each field is gathered, the right information is sent to the left hemisphere and the left is sent to the right hemisphere for processing

Question 7

What was the research Sperry conducted?

Answer 7

Researched 11 people that had the Corpus Callosum cut (for medical reasons)
- Ppt sat in front of a screen and had to fixate on a dot in the centre of the screen
- A stimuli was presented to either the left or right of the dot
- If an object was presented to the right visual field: the ppt can name it
- If an object was presented to the left visual field: the ppt can draw it but not name it

Question 8

Strength: Rogers

Answer 8

Chickens showed enhanced ability to perform 2 tasks at once (vigilant to predators and looking for food)
This suggests lateralisation enhances our brain’s efficiency

Question 9

Strength: Luke

Answer 9

Split brain ppts are twice as quick at identifying “the odd one out” than normal brain controls
Suggests the right and left brain are distinct in function and ability

Question 10

Weakness: link with lateralisation and age

Answer 10

The belief initially is that lateralisation decreases with age after 25 years old
Plasticity states this is not the case if engaging the brain ie in education/experience/meditation

Question 11

Weakness: the case of JW

Answer 11

A split brain patient who developed the capacity to speak using his right brain
Goes against this theory, which states language is left hemisphere only

Question 12

Weakness: methodological problems with Sperry’s research

Answer 12

+ Standardised procedure for all ppts
- Small sample sizes (only 3 in some experiments) -> hard to generalise
- Some had their C.C cut, others severed = decreased validity
- Some ppts were on drug treatment which impacts on “control” = confounding variable

Question 13

RWA

Answer 13

Alien hand syndrome due to split brain