Localisation of functions of the brain Flashcards
Define localisation of function of the brain
Each area of the brain is responsible for a specific function
State the 4 cortex
Motor
Visual
Auditory
Somatosensory
State the 2 areas of the brain
Broca
Wernicke
Describe the motor cortex
Found in both hemispheres
located in the front lobe in front of the central caulks
Involved in the creation of voluntary motor movement
Works contralatterly - each hemisphere control the opposite side of the body
Damage - can cause lost of control over fine movement or paralysed
Describe the somatosensory cortex
In both hemispheres
located in the parietal lobe
Behind the central caulks
receives incoming sensory information from the skin to produce sensations related to pressure, touch, pain, temperature
Damage - problems in perceiving touch
Describe the visual cortex
Found in both hemisphere
In the occipital lobe
Receives info directly from the eyes
works contralaterally
processes visual info-colour, shape or movement.
Damage - blindness, hallucinations, inability to see colour or motion
Describe the auditory cortex
Found in both hemispheres
located in the temporal lobe
responsible for analyzing and processing acoustic information.
works contralaterally
Damage - partial to full hearing loss
Describe the Broca’s area
Found in the left hemisphere
Found in the frontal lobe
Involved in the production of spoken and written language
Damage -:produce brocas aphasia - slow speech that lacks fluency or complete absence of speech
Might produce a short meaningful speech but require a great deal of effort
describe the Wernicke’s area
found in the left hemisphere
located in the temporal lobe
involved in the understanding of language
damage- Wernicke’s aphasia cannot understand spoken language or produces nonsense words as part of their speech
strength of localisation of function of the brain
P - research to support
E- a case study of Phineas Gage who experienced a drastic accident in which a tamping iron , which was a rod used for blasting the dynamite, went through Phineas’ skull when an explosion went wrong.The rod went through Phineas’ chin and out through the top of his head Phineas did not lose consciousness and he could speak throughout the incident and recovery. He recovered well eventually after suffering from a bad infection. Apart from losing his sight in his left eye. Phineas recovered physically well from the injury. However, he was changed psychogically, Phineas before the accident, was described as a calm and well-mannered individual. But, after the accident he showed, unreliable, rude and hostile behaviour
L - This supports the idea of Localisation, and the personality change can be explained by the damage to a specific area of the brain
P - research to support the function of Broca areas
E - a case study conducted by Broca on Louis Victor Leborgne who lost the ability to speak—or speak in any matter that made any sort of sense, other than uttering only a single syllable: Tan, but did not appear to exhibit any signs of physical or cognitive trauma and could still understand language. A post mortem biopsy of his brain revealed a large lesion in the frontal area—specifically, in the posterior inferior frontal gyrus. A few months later another patient called Leborgne, largely lost the ability to speak an autopsied was conducted on his brain and Broca found a lesion that encompassed much the same area as had been affected in Leborgne’s brain.
L- This provides evidence that our speech function was localized
weakness of localised functions of the brain
p- However, although there is evidence from case studies to support the function of the Broca’s area and Wernicke’s area, more recent research has provided contradictory evidence. E- Dronkers et al. (2007) conducted an MRI scan on Tan’s brain, to try to confirm Broca’s findings. Although there was a lesion found in Broca’s area, they also found evidence to suggest other areas may have contributed to the failure in speech production. These results suggest that the Broca’s area may not be the only region responsible for speech production and the deficits found in patients with Broca’s aphasia could be the result of damage to other neighbouring regions
p- psychologists suggest that it is more important to investigate how the brain areas communicate with each other, rather than focusing on specific brain regions.
E- Wernicke claimed that although the different areas of the brain are independent, they must interact with each other in order to function.
E- An example to demonstrate this is a man who lost his ability to read, following damage to the connection between the visual cortex and the Wernicke’s area, which was reported by Dejerine. This suggests that interactions between different areas produce complex behaviours such as language. Therefore, damage to the connection between any two points can result in impairments that resemble damage to the localised brain region associated with that specific function.
L- This reduces the credibility of the localisation theory.
p- critics argue that theories of localisation are biologically reductionist
E - in nature and try to reduce very complex human behaviours and cognitive processes to one specific brain region.
L - Such critics suggest that a more thorough understanding of the brain is required to truly understand complex cognitive processes like language
