L6- Localisation of Function

Question 1

What is localisation of function?

Answer 1

Refers to the principle that functions (language, hearing, memory etc) have specific locations within the brain.

Question 2

Visual centres location?

Answer 2

• the visual cortex is in the occipital lobe of both hemispheres of the brain.

Question 3

How does visual processing happen?

Answer 3

• visual processing starts in the retina where light enters and strikes the photoreceptors.
• nerve impulses from the retina are transmitted to the brain via the optic nerve.
• the majority terminate in the thalamus, which acts as a relay station, passing the information onto the visual cortex.

Question 4

Auditory centres location?

Answer 4

The auditory cortex lies within the temporal lobe in Both hemispheres of the brain

Question 5

How does auditory processing happen?

Answer 5

• the auditory pathway begins in the cochlea in the inner ear, where sound waves are converted to nerve impulses.
• these impulses travel via the auditory nerve to the auditory cortex.
• basic deciding occurs in the brain stem, the thalamus carries out further processing before impulses reach the auditory cortex.

Question 6

Motor cortex location?

Answer 6

Located in the frontal lobe of both brain hemispheres.

Question 7

Motor cortex function?

Answer 7

Is responsible for the generation of voluntary motor movements.

• different parts of the cortex control different parts of the body. These areas are arranged logically next to each other.
• damage to this area can cause loss of muscle function/paralysis in one or both sides of the body.

Question 8

Somatosensory cortex location?

Answer 8

Located in the parietal lobe of both brain hemispheres.

Question 9

Somatosensory cortex function?

Answer 9

Detects sensory events arising from different regions of the body.
- using sensory information from the skin, it produces sensations of touch, pressure, pain and temperature, which it then localises to specific body parts.

Question 10

Broca’s area and Wernicke’s area location?

Answer 10

Broca’s area= Left hemisphere of the frontal lobe.
Wernicke’s area= Left hemisphere of the temporal lobe.
(Are language centres)

Question 11

Broca’s area function?

Answer 11

• area is named after Paul Broca who treated patients who had difficulty producing speech.
• Expressive Aphasia is language/speech problems caused by damage to this area.
• it affects language production but not understanding.
• speech lacks fluency and patients have difficulty with certain words which help sentences function

Question 12

Wernicke’s area function?

Answer 12

Carl Wernicke found patients with a lesion to this area could speak but were unable to understand language.

• concluded the area is responsible for processing of spoken language.
• is connected to the Broca’s area by a neural loop.
• Receptive Aphasia is an impaired ability to understand language.

Question 13

Evaluation of localisation of function?

Answer 13

1. Some functions are more localised than others. Motor and somatosensory functions are highly localised fo specific areas of the cortex. Other functions (personality) are more widely distributed.
2. Bavelier found there are individual differences in which brain areas are activated during silent reading.
3. How brain areas communicate with each other may be more important than specific brain regions. Dejerine reported a patient who could not read due to damage between the visual cortex and Wernicke’s area.