localisation Flashcards
What is the theory of localisation
The theory that different areas in the brain are responsible for different behaviours, processes or activities. (e.g. language, memory, etc.)
A02: case study evidence supporting localisation
Phineas Gage, when in 1848 while werking on a rail line, experienced a drastic accident in which a piece of iron went through his skull:
Although Gage survived this ordeal, he did experience a change in persenality, such as less of inhibition and anger
Describe the motor cortex
Located in the frontal lobe
• Responsible for voluntary movements by sending signals to the muscles in the body.
• Damage to this area may result in loss of control over fine motor skills.
Describe somatosensory cortex
Located in the parietal lobe
• Receives sensory information from the skin to produce sensations (e.g. pain, heat)
• Different parts of the somatosensory area receive messages from different locations of the body
• Receptors for our face and hands occupy over half of the cortex
Describe the visual cortex
Located in the occipital lobe at the back of the brain
• Receives and processes visual information.
• Information from the right-hand side visual field is processed in the left hemisphere, and vice versa
• The visual cortex contains different parts that process different types of information including colour, shape or movement.
Describe auditory cortex
Located in the temporal lobe
• Responsible for analysing and processing acoustic information.
• Information from the left ear gees primarily to the right hemisphere and vice versa:
• It contains different parts i.e. primary auditory area invelved in processing sound, including velume and pitch
What is Broca’s area
Broca (1880s) identified small area in left frontal lobe respensible for speech production:
• Damage to Broca’s area causes Broca’s aphasia (slow speech, lacks fluency)
• Famous patient was fan’ because that was the only word he could say
What is Wernicke’s area
Wernicke (1880s) identified a region in left temporal lobe responsible for language understanding.
• Can speak but words are mostly meaningless as they can’t understand
• Damage to Wernicke’s area results in Wernicke’s aphasia (nonsense words)
A03: Evidence to support through brains scans
(P) Brain scans supports the idea that many everyday brain functions are localised
(EE) Petersen et al (1988) used brain scans to demonstrate how Wernicke’s area was active during a listening task and Broca’s area was active during a reading task.
Semantic and episodic memories stored in different arts of prefrontal cortex.
(L) Therefore, objective methods for measuring brain activity have provided scientific evidence that many brain functions are localised.
A03: counterpoint of evidence from brain scans
P: Psychologists have criticised localisation
EE: Lashley proposed the equipotentiality theory, which suggests that the basic motor and sensory functions are localised, but that higher mental functions are not. He claimed that other undamaged regions can take over specific function following a brain injury
L: This therefore casts doubt on theories about the localisation of functions, suggesting that functions are not localised to just one region, but be holistically distributed instead.
A03: Localisation doesn’t take into account individual differences
P: The idea of localisation fails to take into account individual differences.
EE: Herasty (1997) found that women have larger Broca’s and Wernicke’s areas than men, which can perhaps explain the greater ease of language use amongst women.
L: This, however, suggests a level of beta bias in the theory: the differences between men and woman are ignored, and variations in the pattern of activation and the size of areas observed during various language activities are not considered.
A03: Evidence from neurosurgery
P: Damage to certain areas of the brain has been linked to mental disorders
EE: To treat mental disorders, sometimes neurosurgery is
used to target specific areas of the brain. For example, the cingulate gyrus has been associated with OCD and Dougherty et al (2002) reported that 30% of patients had a successful response to cingulotomy (surgery on this area)
L: The success of these procedures suggests that behaviours
associated with serious mental disorders may be localised.
