Localisation of Function in the Brain Flashcards
What is the localisation of function theory?
The theory that different areas of the brain are responsible for different behaviours, processes or activities
What is the idea of Lateralisation?
The idea that some specific psychological or physical functions are controlled/dominated by a particular hemisphere
Left hemisphere controls right side of body and vice versa
What is the cerebral cortex and what does it do?
It’s the outer layer that covers the inner parts of the brain – about 3mm thick – separates us from animals bc its more complex – grey in colour bc of location of cell bodies
Name the 4 lobes of the brain and one area that’s located in each
Frontal lobe - Motor area
Parietal lobe - Somatosensory area
Occipital lobe - Visual area
Temporal lobe - Auditory area
Name and describe the 4 areas of cortical specialisation in the brain
Motor area - Voluntary movement – separated from the somatosensory cortex by the central sulcus ‘valley’
Somatosensory area - information from the skin (touch, pressure, heat, etc) – the most sensitive areas (face/hands) have more receptors of this area devoted to them
Visual area - Information from the eye - left visual field to right visual cortex and vice versa
Auditory area – analyse speech based information
Damage to any area will affect the corresponding function
Outline the work of scientists, such as Broca and Wernicke, towards the understanding of the brain
Discovered particular areas of the brain are associated with particular physical and psychological functions – first evidence against the previously accepted holistic theory
They discovered the language areas of the brain
Broca’s area is in the frontal lobe and is responsible for speech production – damage leads to Broca’s aphasia – slow, laborious and not fluent speech - Tan
Wernicke’s area is in the left temporal lobe and is responsible for speech understanding/comprehension – damage leads to Wernike’s aphasia – people don’t understand language but produce normal speech
Name 2 study in which localisation of function in the brain has been investigated (Eval +)
Peterson et al. 1988
Tulving 1994
Outline Peterson et al.’s study (Eval +)
They used brain scans to show how Wernicke’s area was active during a listening task and Broca’s area during a reading task, this shows they have different functions
Outline Tulving’s study (Eval +)
Showed that episodic memory and semantic memory are located in different parts of the prefrontal cortex
Provide 2 pieces of supporting evidence for localisation of brain function
Neurosurgical evidence - Dougherty (2002) - 44 OCD patients underwent a cingulotomy (removal of part of the brain). After 32 weeks almost half of the patients had made either a partial or successful recovery from OCD -Suggest behaviour and mental illnesses are localised
Case study evidence - Phineas Gage. A steel rod went through part of his brain removing a lot of the left frontal lobe, this changed his personality from a relative nice person to rude, quick tempered and aggressive, suggests localisation of brain functions
What is meant by plasticity and why does it challenge the idea of localisation?
When the part of the brain is damaged and a particular function of the brain has been lost another part of the brain appears to be able to take over this function.
The brain physically adjusts the location of the function if damage occurs. This suggests that functions are not fixed to a specific position - the brain is working as a whole unit rather than specific areas for specific purposes.
