NEUR1020 W9

• What does brain laterality mean?

  When some brain functions rely more on one side of the brain than the other
• What functions are more lateralised in the left hemisphere of the brain?

  Language and speech
• What functions are more lateralised in the right hemisphere of the brain?

  Tone of voice, prosody (sound rhythms), face perception, perceptual grouping
• What does contralateral and ipsilateral mean?

  Contralateral --> opposite side

  Ipsilateral --> same side
• Which functions map to contralateral areas in the brain?

  Motor, sensory and visual
• What does the left hemisphere control in contralateral functions?

  Right body movement, sensation and vision
• What does the right hemisphere control in contralateral functions?

  Left body movement, sensation and vision
• Is there an overall "dominant hemisphere" for language and hand dominance?

  No
• Which hemisphere do right-handed people have language in?

  95% in the left hemisphere
• Which hemisphere do left-handed people have language in?

  70% in the left hemisphere
• How is primary motor and sensory cortex controls linked?

  Connected contralateral
• How is visual space mapped to the visual cortex?

  Contralateral. Left side of vision goes to right hemisphere, etc
• How is vision from each retina obtained and to which hemisphere does it travel to?

  Input to each half retina of each eye is split. So, left vision from both eyes goes to right hemisphere, and right vision from both eyes goes to left hemisphere. This is important for 3D depth perception
• How does the corpus callosum relate to brain laterality?

  Axons of neurons (nerve fibres) cross to the opposite hemisphere via the corpus callosum, allowing transfer of information between the hemispheres
• Which side of the screen will language in left hemisphere be responsive to?

  Right side of the screen
• If stimuli is shown on the left side of the screen, how will language on the left hemisphere report this?

  Stimuli will move to the right hemisphere. This must cross to the left hemisphere for language. This is done by the inter-hemispheric communication across corpus callosum
• What did Sperry and Gazzainga show that the right hemisphere is generally unable to do?

  Produce verbal responses
• What can the right hemisphere only do when stimuli is shown?

  Can only show it via the left hand (contralateral)
• What is epilepsy?


  Abnormal discharges in electrical activity in the brain
• What is the Wada test?

  Technique that consists of anaesthetising one hemisphere selectively and then retesting cognitive function
• What could H.M. not do after removing his hippocampus from both hemispheres?

  Could not form new memories, recall anything after surgery and remember learning new skills
• What could H.M. still do after his epilepsy surgery?

  Remember and recall things from before the surgery, mentally rehearse to remember things for a few seconds, and learn new skills
• What did we learn about memory from H.M.'s case?

  Memory is not one thing, and are different components mediated by different parts of the brain
• What are 2 crucial processes of long-term memory?

  Encoding (laying down new memories for long-term storage) and retrieval (retrieving memories for conscious recall)
• What are the 2 types of long-term memory?

  Declarative (conscious recollection, things you can declare) and procedural (not for conscious recall, skills you learnt)
• What are the 2 types of declarative long-term memory?

  Episodic (memory of past events/episodes and things you've seen and done) and semantic (facts and basic knowledge you can recall and declare)