sensory systems

Question 1

how is the visual system organised in a hierarchical manner?

Answer 1

sensory processing is organised in a hierarchical manner as different areas have different functions
area V2 = fills gaps in visual field
area V4 = colour processing
area V5 = movement

Question 2

what is the sensory modality what doesn’t go through the thalamus?

Answer 2

smell

Question 3

what is the arcuate nucleus involved in?

Answer 3

appetite control

Question 4

if a patient had a stroke that causes damage to their V5, what would they find it difficult to do?

Answer 4

cross the road because they cannot tell whether traffic is moving or not

Question 5

what the primary auditory pathway?

Answer 5

via the cochlea; sound waves convert to electrical signals
sound actives the hair cells
high frequency is transduced as the base
low frequency sound is transduced at apex

Question 6

what are the 3 main causes of deafness?

Answer 6

• conduction deafness = disorders of the outer or middle ear which prevent sound vibrations reaching the cochlea
• sensorineural deafness = an inability of the auditory nerve fibres to be excited in the normal manner
• central deafness = damage to auditory brain centres, seldom a simple loss of hearing

Question 7

what does the vestibular organ do?

Answer 7

• the inner ear
  provides the sense of balance and the information about body position

Question 8

what is localisation of sound?

Answer 8

dependent on different characteristics of a sound arriving in each ear
- intensity difference = difference in intensity of the sound between the 2 ears
- latency = phase shift between the 2 ears, due to slightly different distance to reach each ear
- duplex theory = sound location depends on intensity, combination and latency