Discuss localisation of function in the human brain. (16 marks)
Outline:
Different parts of the brain are responsible for different, specialised functions
E.g. motor cortex, frontal lobes, voluntary movements
Also specialised laterally, left hemisphere controls right side, vice versa
Somatosensory cortex, parietal lobes, sensory information from skin, e.g. pain/temperature
Damage to certain parts, impairs function that the region was responsible for
Language centres, left hemisphere
Broca, post-mortem, Broca’s aphasia (understand language but unable to produce it), damage
to left frontal lobe
Broca’s area, speech production
Wernicke’s aphasia (nonsense speech), left temporal lobe language comprehension
Evaluation:
P: evidence for plasticity, holistic brain with distributed skills
E: stroke patients recover, areas compensate for damaged regions
A: brain as one unit, not specialist sections
A: born blind, other senses enhanced, visual cortex used for other skills
L: Lashley, equipotentiality limits localisation
P: evidence for Broca and Wernicke, post-mortems unreliable
E: damage in brain unrelated to aphasia, confounding variables – e.g. cause of death/age
A: small sample sizes, inappropriate to generalise universally
A: new interpretations of Broca, damage more widespread, damage to Broca’s area only would
cause temporary not permanent damage
C: Petersen, brain imaging, Wernicke active in listening tasks, Broca active in reading tasks
L: supports localisation, two specialist regions with distinct functions, brain scans credibility of
psychology as a science
Outline:
Different parts of the brain are responsible for different, specialised functions
E.g. motor cortex, frontal lobes, voluntary movements
Also specialised laterally, left hemisphere controls right side, vice versa
Somatosensory cortex, parietal lobes, sensory information from skin, e.g. pain/temperature
Damage to certain parts, impairs function that the region was responsible for
Language centres, left hemisphere
Broca, post-mortem, Broca’s aphasia (understand language but unable to produce it), damage
to left frontal lobe
Broca’s area, speech production
Wernicke’s aphasia (nonsense speech), left temporal lobe language comprehension
Evaluation:
P: evidence for plasticity, holistic brain with distributed skills
E: stroke patients recover, areas compensate for damaged regions
A: brain as one unit, not specialist sections
A: born blind, other senses enhanced, visual cortex used for other skills
L: Lashley, equipotentiality limits localisation
P: evidence for Broca and Wernicke, post-mortems unreliable
E: damage in brain unrelated to aphasia, confounding variables – e.g. cause of death/age
A: small sample sizes, inappropriate to generalise universally
A: new interpretations of Broca, damage more widespread, damage to Broca’s area only would
cause temporary not permanent damage
C: Petersen, brain imaging, Wernicke active in listening tasks, Broca active in reading tasks
L: supports localisation, two specialist regions with distinct functions, brain scans credibility of
psychology as a science
