Localisation Of Brain Functions Flashcards
What is the holistic view?
All parts of the brain were involved in the processing of thoughts and actions.
What is the localisation theory?
Different parts of the brain perform different tasks which are involved in different parts of the body.
What is lateralisation
Some of our physical and psychological functions are controlled or dominated by a particular hemisphere
What supports the idea of lateralisation in the brain?
The 4 lobes perform different functions.
Discuss the different lobes in the Brain
Frontal lobe is responsible for the motor cortex which controls voluntary movement on the opposite side of the body.
Parietal Lobe is responsible for the somatosensory cortex which represents sensory info from the skin
Occipital Lobe is responsible for the visual cortex which receives and processes visual info
Temporal lobe is responsible for the auditory cortex which analyses speech based info
What side of the brain is the language area?
The left side
Talk about Broca’s area
Broca found a small area in the left frontal lobe which is responsible for speech production.
Damage to this area results in the production of slow speech which is laborious and lacks fluency.
Talk about Wernick’s area
Wernick discovered an area in the left temporal lobe that is responsible for language comprehension.
Damage to this area results in the production of nonsense words as part of the content of their speech (Wernick’s aphasia)
Evaluation: Describe the case of Phineas Gage which supports the idea of localisation.
In 1848, Gage was working on a rail road when an explosion occurred. As a result of the explosion, a 3m pole went through his left cheek, behind his left eye and leave his skull from the top of his head.
Gage survived the incident but he lost most of his left frontal lobe.
After the incident, there was a change in personality. Gage went from being calm & reserved to rude and quick tempered
This suggests the frontal lobe may be responsible for regulating mood.
Evaluation: Evidence from Brain Scans
Evidence supporting the idea that many neurological functions are localised
Peterson used brain scans to demonstrate
how Wernick’s area was active during a listening task and Broca’s area was active during a reading task, suggesting that these areas are responsible for specific functions.
Through FMRI and PET scans which measure brain activity, they provide sound scientific evidence for the localisation of brain function.
Evaluation: Against Localisation due to Brain Plasticity/Cortical Remapping
When the brain has become damaged through illness or injury and a specific function has been lost.
The rest of the brain appears to reorganise in attempting to recover the lost function.
Lashley described this as the law of equipotentiality whereby surviving brain circuits chip in so the same neurological action can be achieved. This doesn’t happen all the time but there are cases of stroke victims being able to recover these abilities, that were lost as a result of the illnesses.
This lends supports to the holistic view rather than the localisation theory as it suggests hat all parts of the brain are capable of processing thought and action.
