Localisation of function Flashcards
Robert suffered a stroke at the age of 55. After the stroke he was paralysed down his right side, though he could move his left arm and leg easily. Robert could clearly understand what was said to him, but was unable to produce any speech.
Discuss how knowledge of hemispheric lateralisation and language centres in the brain has helped our understanding of cases such as Robert’s.
Refer to Robert’s case in your answer
- different parts of the brain perform different functions
- functions are specific to individual parts of the parts
what two halves is the brain divided into
the left and right hemisphere which are divided by a small gap
what is localised to the left hemisphere
language
what is localised to the right hemisphere
spatial skills
what is hemispheric lateralisation
different sides of the brain perform different functions
Patient tan lost the ability to speak. Based on your knowledge of hemispheric lateralisation, where did Tan have damage
left hemisphere
what is Contralateral organisation
is when the right hemisphere controls the left side of the body, and the left hemisphere controls the right side of the body.
what are both hemispheres of the brain involved in
the 5 senses and controlling our movement
how do the right and left hemisphere communicate
communicate by sending nerve impulses to each other using the corpus callosum.
what is the The corpus callosum
a bundle of axons that connect the hemispheres. It acts as a bridge between the two hemispheres
Explain what is meant by contralateral brain organisation
Contra means ‘opposite’, and lateral means ‘side’, so contralateral means that some functions of the brain controls the opposite side of the body. Contralateral brain organisation means that the right hemisphere controls the left side of the body, and the left hemisphere controls the right side of the body.
what does it mean if some functions are processes by only one side of the brain
they are hemispherically lateralised
what is the cortex
the outer surface of the brain
what does the motor cortex do
controls body movement on the right side of the body
what does the somatosensory cortex do
processes the feeling of touch. the somatosensory cortex in the right hemisphere controls the left side of the body. and the somatosensory cortex in the left hemisphere controls the right side of the body
where is the somatosensory cortex located
behind the motor cortex
how does the auditory cortex process sounds
by receiving nerve impulses or impulses from sensory neurones that talk to sensory receptors in the ears
where is the auditory cortex located
behind and slightly below the somatosensory cortex
what does the auditory cortex do
processes sound. There is an auditory cortex in both hemispheres, but the auditory cortex is not organised contralaterally
where is the visual cortex located
right at the back of the brain
what des the visual cortex do
processes vison. Both hemispheres are involved in processing vison. The visual cortex works by receiving nerve impulses from sensory neurones that talk to sensory receptors in your eyes. Vison is organised contralaterally
where is the brocas area located
below and slightly in front the motor cortex
what is the function of brocas area
involved in producing language, so we can say it is hemispherical lateralised to the left hemisphere
where is the Wernickes area located
behind the auditory cortex
what is the function of wernickes area
- enables us to understand written language
- enables us to understand speech
- hemispherically lateralised to the left hemisphere
what is aphasia
- when people lose the ability to produce language
- when people lose the ability to understand language
what is brocas aphasia
inability to produce language
what is Wernickes aphasia
inability to understand language
Bella was in a terrible car crash and received severe damage throughout the whole cortex of her right hemisphere.
What symptoms would we expect Bella to exhibit?
- Loss of vision to the left of her body.
- Loss of movement to the left half of her body
- Loss of sensation of touch to the left half of her body.
In a conversation, Joseph listens and can understand what people are saying. However, he struggles to express himself verbally. His dad suggested that he writes down what he thinks, or acts it out, but he struggles with this too - his left hand and arm feel like they’re not doing what he wants them to do.
Using the information above, explain what areas of Joseph’s brain might be damaged and why.
Joseph’s Broca’s area could be damaged because he is struggling to create language - he can’t find the right words to express himself. His right motor cortex may also be damaged, because he is struggling to use his left arm and hand, and his right motor cortex controls the left side of his body. Joseph isn’t having any problems with touch sensations, right side of his body or understanding language, so his somatosensory cortex, left motor cortex and Wernicke’s areas seem to be ok.
what are the limitations of localisation of function
- may be over simplified because a complex function often requires more than one brain region/ area
- ignores the importance of communication between brain regions
- it ignores individual differences in brain organisation
what are the criticism of patients tan research
Dronkers found that patient tan had damaged other regions of his brain outside of Brocas area. Dronkers supports the idea that more than one region is responsible for language production
Explain why case studies of patients like Tan support the idea of brain localisation.
Tan displayed difficulties with producing language, and after he had died a post-mortem examination showed damage to his Broca’s area. This suggests that damage to that particular area had caused Tan’s symptoms, supporting that different areas have specific functions.
Explain what Dejerne’s study tells us about brain localisation.
The study demonstrates that the idea that only one brain region contributes to a function is over-simplified. It also shows that even the idea of multiple brain regions contributing to a function is over-simplified. The study illustrates the importance of communication between brain regions, rather than just looking at one area as important to a function.
what does localisation of function mean
Localisation of function is the theory that different areas of the brain are responsible for different behaviors, processes or activities.
