localisation of function

occipital lobe

• Located at the back of the brain

• It contains the visual cortex, because it deals with visual information sent to it from the retinas

 

parietal lobe

• Receives information from the senses to understand the world around us

• It does this through integrating somatosensory (touch) information with proprioception (information form the limbs about where they are in space)

• It receives information from the occipital lobe about vision

temporal lobe

• The temporal love is at the sides of the brain, at the temples

• It is responsible for memories, emotions and language comprehension

• It is what we use to recognise objects and people

• It is where the Wernicke’s area is

frontal lobe

• Located at the front of the brain

• It is the largest lobe in the human brain, important for voluntary movement, expressive language and for cognitive skills including planning, organising, initiating, self-monitoring and response control

• The frontal robe is considered to be responsible for our personalities

 

Hubel & Weisel (1960s)

• In the 1960s ran a whole series of studies to see what specific neurones were doing in kittens during visual tasks

• They found that patterns shown to the kittens activated specific parts of the brain (showing localisation of function) and other patterns activated other parts of the brain

Broca’s area

• Broca’s area (speech production):

  • Located in the left frontal lobe

  • Responsible for speech production

  • Linked to motor aspects of language (e.g. moving mouth, tongue, vocal cords)

• Damage - Broca’s aphasia:

  • Speech becomes slow, laboured and lacking fluency

  • Content words may remain but grammar is poor

  • Comprehension is relatively intact

Wernicke’s area

• Wernicke’s area (language comprehension):

  • Located in the left temporal lobe

  • Responsible for understanding spoken and written language

  • Involved in processing meaning of words

• Damage - Wernicke’s aphasia:

  • Speech is fluent but meaningless

  • Many include neologisms (made-up words)

  • Comprehension is impaired

strength of theory of localisation of function in the brain

• There is robust evidence to support the idea of LOF

  • Maguire et al. (2000) found that spatial navigation is localised to the posterior hippocampus via analysis of MRI scans

  • Case of Phineas Gage (Harlow, 1848) linked personality changes to damage in the frontal lobe caused by an iron bar shooting through his eye socket and out through the top of his skull

  • Petersen et al. (1988) - PET scans found that Broca’s area is active when reading; Wernicke’s area is active when listening

• The techniques used to find supporting evidence for LOF are objective and clinical

  • This means that the procedure can be replicated to check for consistency

  • Therefore these techniques are high in reliability

weaknesses of theory of localisation of function in the brain

• The biggest criticism of LOF was presented by Lashley (1950), who researched rats which had parts of their cortex removed

  • The rats’ ability to navigate and memorise routes through a maze did not appear to correspond with any specific brain region

  • Lashley concluded that cognitive functions are shared across the cortex holistically rather than being localised to one structure/region

• Lashley also suggested that the law of equipotentiality as a challenge to LOF

  • This law states that when one part of the brain (specifically the cerebral cortex) is damaged, another part of region can take over

  • Research into neuroplasticity supports this