the principle that specific functions have specific locations within the brain
what are these specific functions?
language, memory, hearing etc
what is the motor cortex responsible for?
the generation of voluntary movements
where is the motor cortex located?
frontal lobe, along the precentral gyrus
both hemispheres of the brain have a motor cortex, with the motor cortex on one side of the brain controlling the muscles on the opposite part of the body
how are the regions of the motor cortex arranged?
they are arranged logically next to each other
what is the somatosensory cortex?
detects sensory events arising from different regions of the body
where is the somatosensory cortex located?
parietal lobe, along the postcentral gyrus
what is the postcentral gyrus?
the area of the cortex for the processing of sensory information related to touch
how does the somatosensory use information from the sensory receptors?
it produces sensations of touch, pain, and pressure, it then localises to specific body regions.
Visual Centres:
primary visual centre is located in visual cortex, in the occipital lobe
visual processing begins in the retina & transmitted to the brain via the optic nerve
majority of these impulses terminate in the thalamus
the thalamus acts like a relay station & passes info. to the visual cortex
visual cortex spans both hemispheres, right receives input from left side vice versa
it also contains different areas that process different information (e.g. colour/movement)
auditory centres
concerned with hearing
most of this area lies on the temporal lobe (auditory cortex)
auditory pathways begin in the cochlea (sound waves are converted to nerve impulses
on the way from cochlea to brain; 1st stop brain stem
Brain stem - basic decoding (duration/intensity of sound)
thalamus - relay station & carries out further processing of auditory stimulus
what are the two areas of the language centres?
Brocas & Wernicke
what was the case study for Broca's area?
Tan could understand a spoken language but would not write or speak the language
what did Broca find?
he studied 8 other patients, they all had lesions in their left frontal hemisphere
those with damage to their right hemisphere did not have the same problems
what did his findings make him conclude?
the existence of a language centre
where is this language centre located?
posterior portion of the frontal lobe of the left hemisphere
what is Wernicke's area responsible for?
understanding language
where is Wernicke's area located?
posterior portion of the left temporal lobe
wernicke's area could speak but were unable to understand the language
what did Wernicke propose?
language involves separate motor and sensory regions
the motor region is close to the area that controls the mouth, tongue, and vocal cords. the sensory region is close to the regions of the brain responsible for auditory and visual input.
what is the arcuate fasciculus?
a neural loop that goes from the Wernicke and Broca area
at one end lies the Broca area, responsible for the production of language, and at the other end the Wernicke area, responsible for processing language