4.2.2 - Localisation Of Function Flashcards
What is localisation of function
The theory that suggests hat specific areas of the brain are associated with particular physical and psychological functions
What is the case if phineas gage
- an iron rod shot straight though his head
- the rod shot through his frontal cortex
- after 3.5 months gage was able to live a relatively normal life
- his friends/ family noticed slight changes to his personality and behaviour- he was a less efficient worker and lost his job because of it
- he was ruse and not considerate of others, swears more and will only do what he wants to do
- he was described as no longer gage
- by his death he regains almost all of his previous social skills
What was concluded after case study of phineas gage
- the change in gages personality and temperament suggests that the frontal lobe may be responsible for regulating mood
- he went from calm and reserved to someone who was quick-tempered and rude which are significant changes in his personality
What are the 3 main sections of the brain
- Central core
- limbic system
- cerebrum
What is the role of the central core and what does it consist of
- regulated most primitive and involuntary behaviours
- includes the brain stem and regulates the endocrine system
- it also regulates behaviours such as eating and drinking
What is the role of the limbic system and what does it consist of
- controls our emotions
- sits around the central core of the brain
- contains structures such as the hippocampus
What is the role of the cerebrum and where is it located
- the outer layer of the brain is the cerebral cortex, it appears due to location of cell bodies and therefore grey matter is created
- this regulates higher intelctiual processes
- it is made up of the two hemispheres ( each of the hemispheres are contra- lateral
What is the function of the frontal lobe
- personality
- planning
- decision making
- abstract thought
- reasoning
What is the role of the motor area
Voluntary movement
Somato sensory area
Processes sensory information from sense organs
What is the role of the parietal lobe
Physical sensation from skin and muscles
What is the role of the temporal lobe
- hearing
- language
- memory
What is the role of the occupational lobe
Sight
What is lateralisation
The dominance of one hemisphere of the brain for particular physical and psychological functions
- due to the split of the cerebrum into two hemispheres
What are the language centres of the brain
Language tends to only be on the left side of the brain, there’s are two know areas that control language- Broca’s area and wernickes area
What is Broca’s area
· The Broca’s area is named after Paul Broca, who discovered this region while
treating a patient commonly referred to as tan
· Tan could understand spoken language but was unable to produce any coherent words, and could only say ‘tan’
· After Tan’s death, Broca conducted a post-mortem examination on Tan’s brain
· he discovered that tan had a lesion in the left frontal lobe
· This led Broca to conclude that this area was responsible for speech production
· people with damage to this area experience Brocas aphasia which results in and slow and inarticulate speech.
What is wernickes area
· Carl Wernicke discovered another area of the brain that was involved in understanding language.
· Wernicke found that patients with lesions to Wernicke’s area were still able to speak, but were unable to comprehend language.
· Wernicke’s area is found in the left temporal lobe, and it’s thought to be involved in language processing/comprehension
· people with damage to this area struggle to comprehend language often producing sentences that are fluent, but meaningless (Werniche’s aphasial
· Werniche concluded that language involves a separate motor and sensory region.
- motor in brocas and sensory in wrernickes
How to evaluate localisation of function
Evaluating the theory that different parts f the brain have different jobs and functions
How to evaluate localisation of function
Evaluating the theory that different parts of the brain have different jobs
A03: research support
-
Peterson (1998) used brain scans to she wernickes area active during listening task, and
Broca’s area active during a reading task - shows the difference in fin sections between the two areas
- explains the traits of Wernicke’s aphasia and brocas aphasia
- Tulving (1994) revealers that semantic and episodic emeries activate different parts if the prefrontal cortex
- supporting evidence to theory
- increases external validity and gives explanatory power
A03: case study support
- case of gage useful in finding out what parts of the brain are used to regulate mood
- however could be due to trauma, and is unethical to repeat so internal validity is lowered
A03: non supporting evidence
- ** Karl l Ashley (1950)** suggests the basic motor and sensory functions are localised but nothing more complex
- he removes different areas of the cortex of rats ( between 10%- 50% of their brains) that were learning a maze
- no area was proven to be any more important than another in terms of the rats ability to learn the maze
- the process of learning appeared to occur in any part of the cortex as the time it took the rats to complete the maze varied between groups (10%, 20% etc..)
- these findings suggest that learning occurred in several different areas, lowering the external validity of the theory
- however rats are not humans so the results cannot be accurately generalised to humans
