Colour Flashcards
What is colour perception
Bring lots of contrast to everything
Very useful
What is colour vision related to
Properties of opsins in cones —> sensitive to diff wavelengths
Name the cones that see diff types of light
S cones for short wavelengths = blue
M cones for medium wavelengths = green
L cones for long wavelengths = red
What is inverted spectrum
Hypothetical concept pertaining to philosophy of colour - of 2 ppl sharing their colour vocabulary and discriminations
Colours one sees = qualia = systemically different from colour other person sees
What is qualia
Subjective, first person experience of perception and sensation that are inherently personal and difficult to communicate or measure
Represent what it is like aspect of seeing world
Disproves physicalist view of world
= how things perceived subjectively
Colour = something mind makes up, not actually a colour, wavelengths projected -> brain sees colour
Name exs of qualia
Redness of red
Bitterness of coffee
Pain of a headache
Sound of violin
Marys room thought experiment = set up - Mary’s confinement
Proves that qualia matters
Marys knows everything about science of colour vision - 3rd person perspective
Lives whole life in black and white room - has only black and white materials and views world through black and white monitor
Has never experienced colour first hand
Marys room thought experiment = her knowledge
Mary learns everything about physical processes of colour vision = how light waves of certain wavelengths stimulate photoreceptors in retina - how signals processed in brain - how colour’s perceived
= Mary knows all about physical facts of colour vision
Marys room thought experiment = key moment
One day = Mary released form black and white room = sees colour for first Tim
= learns something from 1st person perspective = learns what colour feels like
Marys room thought experiment = philosophical question
Does Mary learn something new when she experiences colour for the first time
= if she does = means there is more to knowing about colour than the physical facts = subjective experience of qualia
Learned qualia of colour - learned something nonphysical when got out of room
Marys room thought experiment = implications
Against Physicalism (the idea that only physical/material things exist):
* If Mary learns something new upon experiencing color, it suggests that physicalism is incomplete because it cannot account for the subjective, experiential knowledge (qualia) of seeing color.
In Favor of Dualism or Non-Physicalist Views:
* The experiment supports the idea that subjective experiences (qualia) are a separate kind of knowledge that cannot be fully explained by physical facts alone.
Conclusions = idea that everything physical/material is limited - there are things in this world that are purely mental = how things feel to us
What does qualia lie at the heart of
Lie at heart of hard of problem of consciousness
Describe the hard problem of consciousness
Chanllenge remains in exploring why and how neural processes give rise to subjective experience
Questions how mere electrochemical activity in brain translated to lived experiences
No widely excepted framework for bridging the gap between neural activity and emergence of qualia = making it one of the most profound mysteries in philosophy and cognitive science
What is basis of colour perception - explain fully
Cone cells
Cannot Perceiev colour based on activity of just one type of cone cells
Did types cones more sensitive to a specific wavelength
Describe principle of univariance
Infinite set of different wavelength x intensity combos can elicit same response from single type photoreceptor
= so one type of photoreceptor cannot make colour discriminations
How’s does each photoreceptor respond to light
Each cone cell in retain responds to light by generating signal proportional to amount of light it absorbs
Why can’t a single photoreceptor distinguish colour
Bc = bright but less preferred wavelength = weakly absorbed colour at high intensity
Dim but highly preferred wavelength = strongly absorbed colour at low intensity
= give same response
Cannot distinguish between blue and red or between green and yellow
What do we need to see colour
Need to have more than one photoreceptors reacting
Bc many brightness levels irl = level of activity of cone driven by any combo of intensity and wavelength
Describe what is needed for every wavelength
Need 3 cones
For every wavelength = particular combo for activity across the 3 types of cones - remains constant for diff intensities
= resolves problem of univariance and allows colour perception - pattern unaffected by intensity - relative degree of activity perserved (even if cones shifted up)
Describe what happens when missing m cones - gen
Every frequency above s cone limit only encoded by l cones = can produce same response for diff wavelengths/intensity combos
But colours to left perserved
Describe what happens when missing m cones - graph
Cannot see indigos
- only l cones on left = colour only encoded by 1 cone = cannot discriminate = problem of univariance = Cannot tell difference between red and green
How many ppl colour blind
8% males
0.5% females
Have some form colour deficiency = blindness
More common in males bc colour normally caused by recessive gene on X chromosome - most women have other x to compensates
Define colour anomalous
Term for “colour blindness”
Most colour blind ppl can still make discriminations based on wavelength - just diff from norm
Describe deuteranope
Due to absence m cones
