Localisation of Function

• (AO1) Define localisation of function + Lashley

  Specific areas of the brain are responsible for specific functions. E.g. the motor cortex is highly localised to voluntary movements.

  
  

  Lashley's theory of equipotentiality states that while sensory and motor functions are localised, higher cognitive functions, such as language, are more distributed across the brain rather than confined to specific areas.
• (AO1) Draw out the diagram of the brain, including motor, somatosensory, visual, auditory and motor cortexes with broca and wernicke area

  The diagram:

  A) motor cortex

  B) somatosensory cortex

  C) visual cortex

  D) Wernicke's area

  E) auditory cortex

  F) Broca's area

  
• (AO1) State where the motor cortex is located, what hemisphere and its function

  Location: Frontal lobe

  Hemisphere: Both (left and right) = the motor area on one side of the brain controls the muscles on the opposite side.

  Function: Responsible for voluntary movements by sending signals to muscles in the body.
• (AO1) State where somatosensory cortex is located, what hemisphere it is and its function

  Location: Parietal lobe

  Hemisphere Both (left and right) = The somatosensory area on one side of the brain receives sensory information from the opposite side of the body

  Function: Receives sensory information from skin to produce sensations related to pain, pressure and temperature
• (AO1) State where visual cortex is located, what hemisphere it is and its function

  Location: Optical Lobe

  Hemisphere: Both (left and right) = information from the right hand side visual field is processed in the left hemisphere and visa versa.

  Function: The visual area receives and processes visual information. The visual area contains different types of information including: colour, shape or movement.
• (AO1) State where the auditory cortex is located, what hemisphere it is and its function.

  Location: Temporal lobe

  Hemisphere: Both (left and right). Information from the left ear goes primarily to the right hemisphere and visa versa.

  Function: Responsible for analysing and processing acoustic information.
• (AO1) State where the wernicke's area is located, what hemisphere it is, its function and define wernicke aphasia.

  Location: Left temporal lobe

  Hemisphere: Left

  Function: Involved in language comprehension

  Wernicke aphasia: people with damage in this area struggle to understand language, often producing sentences that are fluent, but meaningless
• (AO1) State where the broca's area is located, what hemisphere it is, its function and define broca aphasia.

  Location: Left frontal lobe

  Hemisphere: Left

  Function: Involved in language production

  Broca aphasia = damage to this area causes slow and inaccurate speech
• (AO3) Phineas Gage CS

  Point: The case of PG supports localisation of function.

  
  

  Evidence: PG, a railroad worker, survived an iron rod passing through his prefrontal cortex, but his personality drastically changes - he became more aggressive and lost inhibition. Suggests prefrontal cortex plays role in personality & emotional control.

  
  

  Evaluate: However, alternative explanations exist - his personality changes may have resulted from psychological trauma. Additionally, the lack of modern brain scanning at time means precise area of damage uncertain = weakening conclusions about localisation.
• (AO3) Tan CS

  Point: The CS of Tan also provides evidence for localisation of function, particulary Broca's area being responsible for speech production.

  
  

  Evidence: Tan could understand language but was unable to produce coherent speech, only able to say the word "tan". A post-mortem revealed a lesion in the left frontal lobe, supporting idea that this area is crucial for speech production.

  
  

  Evaluate: However, Tan had extensive brain damage, meaning speech impariment may not have been solely due to Broca'a area. Other damaged areas could have contributed, making it difficult to determine the true extent of localisation.
• (AO3) Prosopagnosia

  Point: Prosopagnosia (face blindness) provides evidence for localisation of function, specifically the role of the fusiform gyrus in facial recognition.

  
  

  Evidence: Individuals with prosopagnosia struggle to recognise faces, even of close family members, despite having intact vision. This condition is linked to damage in the fusiform gyrus, suggesting this area is crucial for processing facial information.

  
  

  Evaluate: Understanding this localisation is important as it helps develop coping strategies & support systems for individuals with prosopagnosia, such as teaching them to rely on other cues like voice / clothing for identification.
• (AO3) Neuroplasticity and Holism

  Point: Strict localisation of function is challenged by neuroplasticity and the holistic nature of the brain.

  
  

  Evidence: Neuroplasticity refers to the brain's ability to change and adapt because of new experiences, suggesting that functions may not be fixed to specific areas. Also, the brain works as an interconnected system rather than isolated regions, with many collaborating for complex tasks.

  
  

  Evaluate: Highlights brain's plasticity and holistic functioning contradict the idea of strict localisation. Shows that while some functions may be localised, many tasks involve multiple areas working together, making localisation more flexible than initially thought.