lecture 10: sensation and perception and human neuropsychology

Question 1

sensation

Answer 1

registering of sensory info by the brain

Question 2

perception

Answer 2

assignment of meaning to that sensory info

Question 3

difference between sensation and perception

Answer 3

• you are able to sense something without actually perceiving it which means these are two different processes
• however sensation and perception do overlap they arent two completely different actions/processes

Question 4

how is sensory information implemented neurally

Answer 4

1. sensory organs absorb energy
2. energy is transduced into a neural signal
3. the neural signal is sent throughout the brain where further processing takes place
   –> we need photoreceptors to take energy in and convert the electromagnetic in and convert it to a neural signal (language of the brain

Question 5

what is the human sensory system responsive to

Answer 5

• a narrow wavelength range called the visible spectrum
  wavelength = colour
  amplitude = brightness

Question 6

structure of the eye:

Answer 6

1. outer later
   –> cornea
   - transparent = good, allows us to see
   - involved in focusing the image on the retina
   - only critical structure on the outside of the eye
2. middle layer
   –> choroid (vascular tunic)
   - eyes blood supply providing nutrient to keep tissue alive and a means to discard waste
   - however it does not cover every bit of the eye
   - serving the function of the choroid is fluid in the anterior and posterior chambers reaching the cornea and lens, respectively
   –> acts like blood but is clear so doesnt impact vision
3. outer layer
   –> iris
   - muscle that gives eyes their distinctive colour
   - can either extend or retract them to let in more or less light
   retract = iris gets larger = more light can be let in
   –> pupil
   - aperture between the iris muscles allowing more or less light into the eye (not a structure)
   –> lens
   - allows for accomodation (focusing near and far)
   cataracts = cloudy lens
   –> retina
   - contains photoreceptors (rods and cones) that convert electromagnetic energy into a neural signal
   - interesting (seemingly backwards) architecture

Question 7

rods and cones

Answer 7

• 120m rods and 7m cones
• perform transduction, converting electromagnetic energy into a neural signal
• properties of rods and cones

Question 8

cones properties

Answer 8

colour: yes
time: daytime
resolution: high

Question 9

rods properties

Answer 9

colour: no
time: nighttime
resolution: low

Question 10

bipolar and retinal ganglion cells

Answer 10

engage in processing the visual image

Question 11

optic nerve

Answer 11

axons of the ganglion cells. size of a pencil

Question 12

blind spot

Answer 12

where the axons of the ganglion cells exit the eye