Localisation and Lateralisation

• Localisation


  Functions occur in specific regions of the brain e.g. speech development in Broca's
• Contralateral


  Each hemisphere controls the opposite side of the body
• Lateralisation


  Each hemisphere is specialised to perform different functions
• Frontal Lobe


  Responsible for voluntary movement and executive functioning
• Temporal Lobe


  Reponsible for processing emotions and interpreting language, associated with memory
• Parietal Lobe


  Responsible for processing info from senses, known as somatosensory info
• Occipital Lobe


  Responsible for understanding visual information, perception and awareness
• Cerebellum


  Responsible for physical movement involving balance and coordination
• Motor Cortex


  Voluntary muscle movement, contralateral

  • Located in the frontal lobe
  • Damage = loss of movement, paralysis
• Somatosensory Cortex


  Recieving sense impressions, contralateral

  • Located in parietal lobe
  • Damage = loss of sensation, neglect syndrome
• Brocas Area


  Speech production

  • Located in the left frontal lobe
  • Damage = Motor aphasia, difficult speech fluency
• Wernickes Area


  Speech comprehension

  • Located in left temporal lobe
  • Damage = Sensory aphasia, difficulty understanding
• Auditory 


  Sound information

  • Located in both temporal lobes
• Visual


  Visual processing

  • Located in both occipital lobes
• (+) A03: Phineas Gage


  Metal rod through the left frontal lobe, created a change in personality and loss of ability to keep job; supports localisation of social behaviour is located in the frontal lobe
• (+) A03: Petersen (1988)


  fMRI brain scans showed that reading (Brocas) and listening (Wernickes) were in 2 different locations shown by activity, supporting localisation of function
• (-) A03: Lashley (1950)


  Dissected Rat brains after learning skills, up to the point they could only just live, finding that they could still do the task, suggesting memories were spread across the whole brain, hindering localisation theory; however maze running requires multiple areas of the brain
• (-) A03: Herasty


  Some women have proportionally larger Broca and Wernicke than men, suggesting we cannot generalise findings due to women having a greater language use, individual differences