Localisation of function in the brain Flashcards
(8 cards)
Describe the differences between the holistic theory, and localised theory of the brain?
-The holistic theory is where people thought all parts of the brain were involved in processing every thought and action
-localisation of brain activity is the theory that different parts of the brain perform different actions/ functions and are involved with different body parts.
What is brain lateralisation?
-The way different hemispheres of the brain have different functions
-e.g. Right hemisphere controls left side of the body and vice versa
What are the 4 lobes of the brain?
-frontal
-parietal
-temporal
-occipital
What are the different areas for each lobe and their function?
-Motor area: (back of the frontal lobe) and is involved with all voluntary movement and damage to this area may result in loss of control over fine movement
-Somatosensory area: (Front of parietal lobe) and is where all sensory information from the skin is represented. The amount of somatosensory area in the brain devoted to a body part denotes how sensitive it is( half of the somatosensory area is used for the receptors in face and hand)
-Visual area: (occipital lobe): left eye sends information to right hemisphere and vice versa and damage to this area could cause blindness
-Auditory area: (Temporal lobe): analyses speech based information and damage to this area may produce hearing loss
What was Paul Broca’s research?
-LH involved with language
-Broca found that the left frontal lobe is involved with speech production
-Damage to Broca’s area causes slow laborious speech and was named Broca’s Aphasia
-One patient named ‘Tan’ as that’s all he could say
-People with Broca’s Aphasia struggle with conjunctions
What was Karl Wernicke’s research?
-Wernicke found that the left temporal lobe is responsible for language understanding
-Damage to this area could speak fluently but would produce nonsensical neologisms
-This was named Wernicke’s area
Strengths of localisation of brain function research
-Evidence from neurosurgery: Neurosurgery may be the last method for treating brain disease targetting specific areas of the brain. E.g. Cingulotomy which is the removal of the cingulate gyrus which has been implicated in OCD. Darin Dougherty et al. (2002) reported on 44 people with OCD after 32 weeks after cingulotomy about 30% had met the criteria for a successful response and 14% for partial response.
HOWEVER: 44 small sample size and 30% is not very significant as that means over 50% did not have any changes and would have paid alot for surgery,
-Evidence from brain scans: Steven Petersen et al. (1988) used brain scans to show how Broca’s area was active during the reading task and Wernicke’s area was active during the listening task. Steven Petersen and Buckner (1996) revealed that semantic and episodic memories reside in different parts of the prefrontal cortex
HOWEVER: contrasting research from Karl Lashley (1950): he removed 10-50% of areas from the cortex in rats learning a route through a maze and found no difference between different areas of the brain and needed the whole cortex- supports holistic view (However, only animal studies)
-Case study of Phineas Gage: Got a tamping iron through the left frontal lobe of his brain, he survived the injury but it was said he turned from a calm man to quick tempered and “no longer Gage”.
Weaknesses of localisation of brain function?
-Contrasting research into language localisation:
Anthony Dick and Pascale Tremblay (2016) found that only 2% of modern researchers think that language in the brain is completely controlled by wernicke’s and Broca’s area which is enabled through progressions in brain imaging such as fMRI and shown some may be involved in RH.
(However, fMri does have a lag of 5 seconds)
