localisation of function

• What is localisation of function?

  The theory that certain functions (e.g. language, memory, etc.) have certain locations or areas within the brain.
• What are the four lobes of the brain?

  Frontal, parietal, temporal, occipital
• What lobe is the motor area in?

  Frontal
• What is the function of the motor area?

  Responsible for voluntary movements by sending signals to the muscles in the body
• What happens if the motor area is damaged?

  Poor coordination of movements and poor dexterity. For example, the person usually loses the ability to perform fine motor movements. Damage in a particular hemisphere will lead to loss on the opposite side of the body
• What is the hemispheric location of the motor area?


  Both
• What lobe is the somatosensory area in?

  Parietal
• What is the function of the somatosensory area?

  Receives incoming sensory information from the skin to produce sensations related to pressure, pain, temperature, etc.
• What happens if the somatosensory area is damaged?

  Somatosensory cortex damage can produce numbness or tingling/prickling sensations in certain parts of the body.
• What is the hemispheric location of the somatosensory area?


  Both
• What lobe is the visual area in?

  Occipital
• What is the function of the visual area?

  Receives and processes visual information. Information from the right VF is processed in the left hemisphere, and vice versa. Contains different parts that process different types of information.
• What happens if the visual area is damaged?

  Leads to blindness in the part of the visual field that corresponds to the damaged area. The area of blindness - known as a scotoma - is in the visual field opposite the damaged hemisphere and can vary from a small area up to the entire hemifield.
• What is the hemispheric location of the visual area?


  Both
• What lobe is the auditory area in?

  Temporal
• What is the function of the auditory area?

  Responsible for analysing and processing acoustic information. Information from the left ear goesprimarilyto the right hemisphere and vice versa. The auditory area contains different parts, and the primary auditory area is involved in processing simple features of sound, including volume, tempo and pitch.
• What happens if the auditory area is damaged?

  Damage may produce partial hearing loss; the more extensive the damage, the more extensive the loss.
• What is the hemispheric location of the auditory area?


  Both
• What lobe is Broca's area in?

  Frontal
• What is the function of Broca's area?

  Speech production
• What happens if Broca's area is damaged?

  People with damage to this area experience Broca's aphasia, which results in slow and inarticulate speech.
• What is the hemispheric location of Broca's area?

  Left
• What lobe is Wernicke's area in?

  Temporal
• What is the function of Wernicke's area?

  Language comprehension
• What happens if Wernicke's area is damaged?

  People with damage to this area struggle to comprehend language, often producing sentences that are fluent, but meaningless (Wernicke's aphasia).
• What is the hemispheric location of Wernicke's area?

  Left
• What is the supporting evidence for localisation of function?

  Phineas Gage
• What happened to Phineas Gage?

  Gage dropped his tamping iron onto the rock causing the explosive to ignite which sent a pole through his left cheek, left eye and exiting at the top of his skull
• Which part of Phineas Gage's brain was damaged?

  Frontal lobe
• What happened to Phineas Gage after the accident?

  Changed from being calm to quick tempered
• How does Phineas Gage support localisation?

  Phineas Gage had damage to one particular area of his brain which caused a change in his personality which supports the idea that this part of the brain is responsible in some way for mood and personality; that there is one part of the brain responsible for one aspect of behaviour
• What is a counter argument for using Phineas Gage as supporting evidence for localisation?

  The case of Phineas Gage is a case study of only one person. Results cannot be generalised from one person to the whole population, therefore it cannot be said if this area of the brain is responsible for personality in all people or even most people
• What is the alternative explanation for localisation of function and who was it proposed by?

  Lashley proposed the equipotentiality theory
• What does the equipotentiality theory propose?

  That the basic motor and sensory functions are localised, but that higher mental functions are not.
• What did Lasley claim about brain damage and injury?

  He claimed that intact areas of the cortex could take over responsibility for specific cognitive functions following brain injury
• How does this alternative explanation challenge localisation of function?

  This therefore casts doubt on theories about the localisation of functions, suggesting that functions are not localised to just one region, as other regions can take over specific functions following brain injury and even that some functions are not localised at all
• How does equipotentiality theory be counter-argued?

  Lashley still accepts that some functions are localised meaning that the theory is still valid in parts. In addition, it may be the case that other regions can take over specific functions following injury but it remains the case that these functions are still localised for most people
• What is a final evaluation point for localisation of function?

  Individual differences
• How do some psychologists argue that the idea of localisation fails to take into account individual differences?

  Herasty (1997) found that women have proportionally larger Broca's and Wernicke's areas than men, which can perhaps explain the greater ease of language use amongst women
• How do individual differences contradict the theory of localisation of function?

  Limited explanation as it does not explain or acknowledge the difference in size of Broca's and Wernicke's areas in men and women. Therefore we are unable to generalise findings about localisation of function to both sexes