Hemispheric Lateralisation Flashcards
hemispheric lateralisation is…
The dominance of one hemisphere of the brain for particular physical and psychological functions e.g. the left hemisphere typically is responsible for language
What lateralisation sections of the brain do we look at?
The language centres:
- Broca’s area
- Wernicke’s area
What sort of things are each hemisphere responsible for?
Right: Face recognition Imagination/creativity holistic processing Left: Logic Reasoning Maths/science skills
What are the percentages for left and right handed people and the hemisphere that controls their language
Right handers -> 96% have a left hemisphere which is dominant
Left handers-> 70% have a left hemisphere which is dominant
Summarise Hellar + Levy (1981)
- the right hemisphere seems to be particularly dominant for recognising emotions in others
- Found that p’s shown a split photo (half smiling/half neutral) would recognise the emotion shown on the left side of the picture
Which hemisphere are the language centres found on?
What is aphasia?
- Left hemisphere
- Language deficit
Broca’s area:
- Posterior region of the frontal lobe of the left hemisphere (lateralised)
- critical for speech production
- found in 1865
- people with Broca’s aphasia could understand language but not speak or write
Wernicke’s area:
- Posterior region of the left temporal lobe (lateralised)
- critical for speech comprehension
- found in 1872
- people with Wernicke’s aphasia were unable to understand language but could speak it
Explain how Broca’s and Wernicke’s work together
- There is a neural loop (articulate fasciculus) running from Broca’s area to Wernicke’s area
- Damage to both areas causes global aphasia - the inability to understand or produce speech
Summarise evaluations of hemispheric lateralisation
- evidence - patient Tan who had Broca’s aphasia
- however this is a case study
- split brain research supports lateralization
- Danelli’s case study of EB questions theory
