Localization of function

localization of function

the idea that different parts of the brain control different parts of the body

Pierre Fleurens found that main divisions of brain are responsible for different

motor

* frontal
* voluntary motor movements
* both hemispheres have different motor cortexes and each hemisphere controls that side of the brain

somatocensory

* parietal
* detects sensory events arising from different regions in the brain
* produces sensation such as touch, pressure, pain
* both hemispheres have different somatosensory cortexes and each hemisphere controls that side of the brain

visual

* occipital
* deals with vision
* retina > optic nerve > brain > thalamus > visual cortex

auditory

* temporal
* sound waves converted into nerve impulses
* cochlea > brain stem > thalamus > auditory cortex

Broca’s area

* speech
* frontal
* main area for speech production
* conducted research with 8 patients who could understand language but could not speak nor express thought through writing
* > identified language center in the frontal lobe
* > second area within Broca’s are which deals with demanding cognitive tasks

Wernicke’s area

* language
* temporal
* research with patients who could speak but couldn’t understand language
* information from sensory and motor regions is transferred to Wernicke’s area which recognizes language an associates it with meaning

AO3: equipotentiality

* Lashley 1930
* argued sensory and motor information are localized because higher functions are not localized.
* claims that certain areas of the brain can take over tasks depending on severity of issue
* > therefore, damage to the brain is determined by severity and not by localization

AO3: communication over localization

* Wernicke discussed the idea of interdependence, explaining that in order for areas of the brain to work, they need to communicate with each other.
* there are connections in the brain to each critical area/lobe
* any damage along those connections could impair functions of a critical area, reinforcing the idea of interdependence

AO3: support for language centers due to aphasia

* (expressive) Broca’s aphasia - an impaired ability to produce language
* (receptive) Wernicke’s aphasia - an impaired ability to understand language
* > reinforces important role of brain localisation within these specific language centres

AO3: gender differences

* Harasty et al 1997
* found that women have proportionally larger Broca’s and Wernicke’s areas than men
* these differences explain the ‘supposed’ superior language skills often found in women