Localisation: the theory that specific areas of the brain are associated with particular physical and psychological functions.
Hemispheres
The brain is split into two hemispheres: the left and right.
Lateralisation: the dominance of one hemisphere of the brain for particular physical and psychological functions.
Language area of the brain: Broca
- Language is restricted to the left side of the brain in most people
- In 1880, Broca identified a small area in the left frontal lobe responsible for speech production
- Damage to Broca’s area causes Broca’s aphasia which is characterised by slow and laborious speech
- Broca’s patients may have difficulty finding words and naming certain objects
Language area of the brain: Wernicke
- In approx. 1880, Wernicke was describing patients who had no problem producing language but severe difficulties understanding it
- Their speed of speech was fluent but meaningless
- Wernicke identified a region, Wernicke’s area, in the left temporal lobe, as being responsible for language comprehension
- This would result in Wernicke’s aphasia when damaged (producing nonsense words in speech)
Video of Fluent Aphasia (Wernicke’s Aphasia)
The Cerebral Cortex
- The outermost layer of the brain
- Appears grey because of the location of cell bodies (“grey-matter”)
- 3mm thick, covers the inner-parts of the brain
- Separates us from animals
- Human cerebral cortex is much more developed
- Allows higher order thinking
Motor Area
- Back of the frontal lobe
- Controls voluntary movements in the opposite side of the body
- Damage to this area of the brain may result in a loss of control over fine movements
Somatosensory Area
- Parietal lobe
- Where sensory information from skin is represented
Visual area
- Back of the occipital lobe
- Each eye sends information to from the right visual field to the left visual cortex, and vice versa
- Means that damage to the left hemisphere can produce blindness in part of the right visual field of both eyes
Auditory area
- Temporal lobe
- Analyses speech-based information
- Damage may produce partial hearing loss
- Damage to a specific area may affect ability to comprehend speech