Hemispheric Lateralisation

Question 1

What is hemispheric lateralisation?

Answer 1

• The idea that two halves of the brain are functionally different and that certain mental processes are mainly controlled by one hemisphere rather than another.

Question 2

Where is language lateralised?

Answer 2

• ## language is lateralised mainly in the LH as this is the location of the Brocas area and Wernickes area

Question 3

What role does the RH have in language

Answer 3

• the RH can produce rudimentary words and phrases and contributes emotional context to language
• This has led to the suggestion that the LH is the analyser and the RH is the synthesiser

Question 4

What functions are not lateralised?

Answer 4

• the vision, motor and somatosensory areas appear in both hemispheres

Question 5

What hemispheres control the motor area?

Answer 5

• the motor area is not lateralised and is instead cross-wired
• The RH controls movement on the left side of the body and the LH controls movement on the right

Question 6

How is vision both contralateral and ipsilateral ( opposite and same - sided)

Answer 6

• each eye receives light from the left visual field and the right visual field
  -the LVF is connected to the right hemisphere and the RVF is connected to the left hemisphere
• this enables the visual areas to compare perspectives and aids depth perception

Question 7

What is a strength of hemispheric lateralisation?

Answer 7

• one strength is that there is research showing that even in connected brains, the two hemispheres process information differently
• For example, Fink (1996) used pet scans to identify which brain areas were active during a visual processing task.
• When participants with connected brains were asked to attend to global elements of an image such as looking at a picture of a whole forest, the right hemisphere was much more active.
• When focused on finer detail (inidividual trees), the LH was more active.
• This shows that visual processing is concered, hemispheric lateralisation occurs

Question 8

What is a limitation of hemispheric lateralisation?

Answer 8

• A limitation is that the idea that the LH is an analyser and the RH is a synthesiser may be wrong
• there may be different functions in the RH and the LH but researchers suggest that people do not have a dominant side that creates a different personality
• Jared Nielsen analysed brain scans of over 1000 people aged 7 - 29and found there was some evidence for hemispheric lateralisation. However, there was no evidence of a dominant side.
• this suggests that the notion of right and left brained is wrong