Lecture 2

Question 1

What does it mean ‘cognition is grounded in perception’?

Answer 1

dreams relate to what we’ve seen
“ I see what you mean”
we understand seasons because we SEE the changes

Question 2

Perception is subjective

Answer 2

we don’t all see the same thing, we all view the same things differently
subject to interpretation

Question 3

Vision starts with the detection of light

Answer 3

light is the stimulus
eyes are the receptors

Question 4

Visual receiving area

Answer 4

deconstructs images

Question 5

specific areas in the visual cortex

Answer 5

different areas in the visual cortex focus on different things. some focus on colour, some horizontal lines and others vertical lines
are visual cortex views things fragmented

Question 6

light is made up of photons

Answer 6

these photons are on different wavelengths depending on their vibrations

Question 7

what wavelength can humans detect

Answer 7

between 400 and 700nm

Question 8

why can’t we see when its dark?

Answer 8

when its dark, there is light energy but as we only see small amounts of visible light, we don’t detect this enerygy

Question 9

different animals = different wavelengths

Answer 9

for example, dogs can’t see red they associate it with green as they have a much smaller wavelength than humans

Question 10

Reflections

Answer 10

light reflects of objects and determines what we see and the colours we view
certain surfaces reflect wavelengths and others absorb it

Question 11

Distal stimulus

Answer 11

the physical objects that reflect light

Question 12

Proximal stimulus

Answer 12

the image of an object on our eyes

Question 13

why do the retinal images appear upside down?

Answer 13

due to the concave surface inside the eye

Question 14

iris

Answer 14

the coloured structure surrounding the pupil

Question 15

pupil

Answer 15

constricts and relaxes to allow light into the eye

Question 16

cornea

Answer 16

transparent structure on the outer eyes surface
yellows with age and scratches

Question 17

lens

Answer 17

focuses light into the eye and onto the back of the eye

Question 18

retina

Answer 18

contains the light sensitive cells - photo receptors

Question 19

fovea

Answer 19

contains majority of the photoreceptors and allows for detail and coloured vision

Question 20

cones

Answer 20

photopic visual system
found near or in the fovea
work best in intense light
detect high wavelengths - bright blue, red and green
detects high frequencies - fine detail

Question 21

rods

Answer 21

scotopic visual system
found in the retinal periphery
work best in low light
detect low wavelengths - greys
detect low frequencies - coarse detail

Question 22

dark adaptation

Answer 22

the gradual improvement in the ability to see in the dark
takes up to 20 minutes
in low light levels, only rod mediated vision is sensitive enough to detect light

Question 23

light adaptation

Answer 23

the gradual improvement to see in dim light
takes 5 minutes
at high light levels, only cone mediated vision is possible, rods become bleached

Question 24

Ganglion cells

Answer 24

receive input and carry information from the eye to the brain

Question 25

Focusing

Answer 25

focusing light on a certain object is known as forviate
allows lots of detail, the rest around you is still colourful when in reality this is an interpretation and not how your brain sees the world as the rods are working and they can’t detect colour or detail (blurry and grey)

Question 26

Why is it hard to read at night?

Answer 26

due to the distribution between cones and rods across the retina

Question 27

Blind spot

Answer 27

a hole in the retina where there are no photoreceptors

Question 28

why aren’t we aware of these blind spots?

Answer 28

as our brain fills in the gaps with “what is mostly likey there”

Question 29

Why do we need to see colour?

Answer 29

important for survival
adds beauty to our lives
a psychological phenomenon

Question 30

hue

Answer 30

the colour quality of the light

Question 31

saturation

Answer 31

purity of the light

Question 32

brightness

Answer 32

amount of light present

Question 33

white surfaces

Answer 33

reflects all wavelengths

Question 34

tri-chromatic system

Answer 34

3 types of cones
short wavelength - blue
medium wavelength - green
long wavelength - red

Question 35

red-green colour deficiency

Answer 35

lost or limited function of the red cone pigments
caused by recessive gene on X chromosome, more common in men
instrumental in realising the existence of 3 types of cones in the human retina

Question 36

opponent process theory

Answer 36

trichromatic theory can’t explain:
the primary colours for most are red, green, blue and yellow
those colour blind to red are also colour blind to green
negative after images

Question 37

opponent process theory

Answer 37

some ganglion cells process information differently about the firing rates of long and medium cones, this gives us the perception of red or green
others process differences between short concessions and long and medium cones, giving s the perception of yellow and blue

Question 38

negative after images

Answer 38

experiences of one collet after the removal of another

Question 39

Is colour vision critical for survival?

Answer 39

people can live with colour deficiencies
we don’t need colour to see motion
colour vision therefore probably it not critical but is a useful ability to have that allows us a fuller experience of the world