3.7. Lateralistion Flashcards
What are the hemispheres we have?
Left and right hemisphere
What are the hemispheres connected by?
Corpus Callosum
What is the Corpus Callosum
A bundle of fibres that allow communication between the 2 hemispheres
What is the role of the right hemisphere?
The synthesiser
Responsible for creativity, facial recognition, awareness of places, objects and contextual perception
Controls left side of the body
What is the role of the left hemisphere?
The analyser
Responsible for academics, speech and language, analysis, sequencing, recognition of names, words, numbers
Controls the right side of the body
How does info get processed in the eyes?
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
What was the research Sperry conducted?
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
Strength: Rogers
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
Strength: Luke
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
Weakness: link with lateralisation and age
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
Weakness: the case of JW
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
Weakness: methodological problems with Sperry’s research
+ 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
RWA
Alien hand syndrome due to split brain
