hemispheric lateralisation & spit brain research

• What is hemispheric lateralisation?

  The idea that each hemisphere of the brain is mainly responsible for certain behaviours and processes.
• How does hemispheric lateralisation contrast with the holistic theory of brain function?

  Hemispheric lateralisation suggests specific functions for each hemisphere, while holistic theory suggests functions are distributed across the whole brain.
• What are the two sides of each visual field and their corresponding brain hemisphere controls?

  • Left visual field processed by the right hemisphere
  • Right visual field processed by the left hemisphere
• What was the purpose of Sperry and Gazzaniga's (1968) split-brain research?


  To investigate the functions of each hemisphere by exposing a single hemisphere to stimuli.
• What surgical procedure did the patients undergo in Sperry and Gazzaniga's study?

  They had their corpres collosum severed .
• Why was it important to cover one of the patients' eyes during the experiment?

  To ensure that information was processed by only one hemisphere.
• How long was the stimulus flashed onto the screen in the experiment?

  One-tenth of a second.
• What were the main findings of the split-brain research regarding language and writing?

  1. Right visual field (left hemisphere): Patient can say the word.
  2. Left visual field (right hemisphere): Patient can write the word but not say it.
• What ability did the right hemisphere dominate in the matching task?

  The ability to match faces to a given stimulus.
• What happens when two words are presented simultaneously to the visual fields?

  The patient says the word from the right visual field and writes the word from the left visual field.
• What occurs when an object is placed in the patient's right hand?

  The patient cannot identify the object because it is processed by the left hemisphere, which lacks visuo-spatial centres.
• What happens when an object is placed in the patient's left hand?

  The patient can identify the object and choose a similar one from a hidden bag.
• What were the confounding variables in Sperry and Gazzaniga's study?

  • Patients were on anti-epilepsy medications.
  • Differences in the extent of lesioning of the corpus callosum.
• What did split-brain research demonstrate about the functions of the two hemispheres?

  • Left hemisphere: Dominant for language tasks.
  • Right hemisphere: Dominant for visuo-spatial tasks.
• What concept did the split-brain research support regarding the mind?

  The idea of a 'dual mind' where the two hemispheres represent two sides of the mind.
• What criticism did Pucetti (1980) raise against Sperry and Gazzaniga's work?

  He pointed out that visual stimuli on the left half of each eye's retina go to the left hemisphere, not the right.
• What misconception about hemispheric functions does the evidence suggest?

  • The left hemisphere is not solely responsible for language.
  • The right hemisphere can also contribute to language tasks in some individuals.
• What is the implication of recruitment of homologous areas in the brain regarding lateralisation theory?

  Each hemisphere is not restricted to specific functions and can adapt to perform tasks typically associated with the other hemisphere.
• What are the two hemispheres of the brain?

  The right hemisphere and the left hemisphere
• How do the two hemispheres of the brain communicate?

  They communicate via the corpus callosum
• What does it mean that the brain operates on a contralateral basis?

  It means the right hemisphere controls the left side of the body and vice versa
• What might be a symptom of a stroke in the left hemisphere?

  Facial drooping or weakness in the right limbs
• What is the primary function of the left hemisphere?

  Language processing and analytical tasks
• Where is Broca's Area located?

  In the left frontal lobe
• What happens if Broca's Area is damaged?

  It leads to Broca's aphasia, characterized by non-fluent speech
• What is Wernicke's Area responsible for?

  Language comprehension
• What occurs when Wernicke's Area is damaged?

  Individuals produce fluent but nonsensical speech and struggle to understand language
• What functions are generally associated with the right hemisphere?

  Visual-spatial processing, creativity, and holistic thought
• What is the role of the right hemisphere in spatial awareness?

  It is crucial for understanding spatial relationships and navigating environments
• How does the right hemisphere handle visual processing?

  It is adept at recognizing faces and interpreting visual stimuli
• Who identified Broca's Area and when?

  Paul Broca in the mid-19th century
• What was the significance of the patient Louis Leborgne, nicknamed "Tan"?

  He could only utter the word "Tan" due to severe language deficits from a lesion in the left frontal lobe
• Who discovered Wernicke's Area and what is its function?

  Carl Wernicke; it is associated with language comprehension
• What did Wernicke's findings indicate about language comprehension?

  Damage to the left temporal lobe impairs understanding of language
• What is the purpose of the corpus callosum?

  It allows for rapid communication between the two hemispheres
• What is corpus callosotomy and when is it performed?

  It is the severing of the corpus callosum to reduce seizure frequency in severe epilepsy cases