Hemispheric lateralisation

• What is hemispheric lateralisation?

  The idea that the two hemispheres of the brain are functionally different.

  
• Which hemisphere is primarily responsible for language according to hemispheric lateralisation?

  The left hemisphere is primarily responsible for language.
• What is split-brain research?

  A series of studies involving epileptic patients with surgically separated hemispheres.
• What is the purpose of cutting the corpus callosum in split-brain research?

  To separate the two hemispheres of the brain.

  
• What is commisurotomy?

  The surgical severing of the corpus callosum.
• How does an object placed in the left hand of a split-brain patient get processed?

  It is processed in the right hemisphere of the brain.

  
• How do the hemispheres of the brain control the body?

  Activity on the left side of the body is controlled by the right hemisphere and vice versa.
• How many patients were involved in Sperry's (1968) studies?

  11 patients.
• What happens when an image is projected to a split-brain patient's right visual field?

  The image is processed by the left hemisphere.

  
• What is the effect of presenting an image to one hemisphere of a split-brain patient?

  The information cannot be conveyed to the other hemisphere.

  
• What was observed when a picture was shown to the right visual field?

  The patient could easily describe what was seen.
• What was the outcome when the same object was shown to the left visual field?

  The patient could not describe what was seen due to lack of language centres in the right hemisphere.

  
• What could patients do with objects projected in the left visual field?

  They could select a matching object using their left hand.

  
• How did the left hand perform in the drawing task when a picture was presented to the left visual field?

  The left hand drew pictures that were more spatially accurate compared to the right hand.
• What is a weakness of Sperry's research regarding generalisability?

  It involved only 11 patients with a history of seizures, limiting generalisability.
• Why is the sample of split-brain patients considered unusual?

  Because split-brain patients are very rare.

  
• What is a strength of Sperry's methodology?

  It used specific and standardised procedures to ensure reliability.
• How did Sperry ensure that only one hemisphere received information at a time?

  By flashing stimuli for only 0.1 seconds.
• Why can Sperry's original split-brain research no longer be repeated?

  Because the operation is no longer performed due to advances in drug treatments.
• What is a limitation of comparing split-brain patients to a neurotypical control group?

  None of the control groups had epilepsy, making causal relationships difficult to establish.
• What did Fink et al. (1996) find regarding brain activity in neurotypical participants?

  The right hemisphere was active when attending to global elements, while the left hemisphere was dominant for finer detail.