Localisation Of Fucntion Flashcards
What is meant by localization of function?
The theory that specific areas of the brain are associated with particular psychical and psychological functions eg temporal lobe helps with sound and listening
What are the three main parts of the brain
- the central core
- the limbic system
- the cerebrum
Central core
- regulates our most primitive and involuntary behaviours such as breathing, sleeping and sneezing
- it includes the brain stem and regulates the endocrine system, it also regulates behaviour such as eating and drinking
- these behaviors are controlled by the core because they were first developed and are most important
The limbic system
- controls our emotions
- sits around the central core of the brain
- it contains structures such as the hippocampus (memory)
The cerebrum
- regulates higher intellectual processes
- outer layer is the cerebral cortex which appears grey because of cell bodies
- made up of left and right hemispheres which are connected by a bundle of fibres called the corpus callosum
Lateralisation meaning
The Dominican of one hemisphere of the brain for a particular psychical and psychological function
Phineas Gage AO1
Aim: To explain the cause of Gage’s change of personality.
Method: Whist working on the railroad, 25 year old Gage was preparing to blast a section of rock using explosives. He dropped his tamping iron onto the rock, which caused the explosive to ignite. The explosion hurled the meter length iron pole, point first through his left cheek. It passed behind his left eye, and exited his brain and skull from the top of his head. It was found 25 to 30 yards behind him covered in bits of his brain. He was knocked over but is not believed to have lost consciousness.
Results: He survived, and after months of recovery wanted to regain his job. Before the accident he had been a most capable and efficient foreman, one with a well-balanced mind, and who was looked on as a shrewd smart business man. However, no one would employ him as his personality had changed from someone who was kind and reserved to someone who was now boisterous, rude and grossly blasphemous. His friends said he was “No longer Gage.”
Conclusion: As Damasio et al. stated; although his accident was horrific, it has taught us a great deal about the complexity of psychological processes that occur in the human brain.
Phineas gage AO3
- case study so not generalizable to public as based on such unique circumstances
- subjective relies of retrospective data (peoples opinions of what he was like before)
- low reliability as cannot replicate scenario
Aphasia meaning
Language disorder
Broca’s aphasia
Loss of ability to produce spoken language
Wernicke’s aphasia
Impaired language comprehension
How have brain scans been used to help establish localization of function?
Peterson (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, suggesting that these areas are localised
Neurosurgery examples
Lobotomy: removal of the brain tissue
Leucotomy: cutting the connections to a particular part of the brain
Neurosurgery is a last resort method for treating some mental disorders by targeting specific areas of the brain which may be problematic. Darin Dougherty et al (2002) reported that 44 people with OCD who had undergone a Cingulotomy (which involves isolating a region called the cingulate gyrus) after 32 weeks (at a post surgery follow up) about 30% of the participants met the criteria for a a successful response to the surgery and 14% gave a partial response. This suggests that behaviour associated with serious mental disorders may be localised
What did Lashley suggest
Karl Lashley (1950) suggested that basic motor and sensory functions were localized but higher cognitive functions are not localized.
Lashley claimed that intact areas of the cortex could take over responsibility for specific cognitive functions following injury to the area normally responsible for that function.
According to this point of view, the effects of damage to the brain would be determined by the extent rather than the location of the damage.
This view received some support from the discovery that humans were able to regain some of their cognitive abilities following damage to specific areas of the brain
What is plasticity
The brains ability to be malleable and adapt to changes if needed.
Why are lobotomies no longer used
No longer used due to ethics. They have severe side effects such as destroying a person’s ability to function and their personalities change.
Whilst they helped with some disorders, they completely fundamentally changed a person ability to behave as ‘themselves’.
Now we understand how important the frontal lobes are, there is no reason why someone should undertake such a dangerous procedure that has such poor recovery and success rates.
Where is Broca’s area on the brain?
U better have done that
Where is the motor area in the brain and what is its function
Voluntary movement
We’re is the somato sensory area in the brain and what is its function
Processes sensory info from sense organs
Where is Wernickes area in the brain?
DO IT BRO
