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other one is too long
what does color correspond to?
corresponds to a specific range of the electromagnetic spectrum
what do colors of light correspond to?
wavelength emitted by a source— color is created in the mind
what are blobs?
cylindrical groups of neurons that are sensitive to colors
where do all these colors from?
emitted light
what is additive color mixing?
when multiple light sources are mixed, their wavelengths are added together
what is additive color mxing/emitted light consist of?
RBG
what does subtractive color mixing/reflected light consist of?
CMYK
what would classify as emitted light?
projecting lights on a white background, tvs, and computer screens
what is reflected light?
colors of objects correspond to wavelengths that are reflected off an object
what color does s cones see?
blue
what color does m cones see?
green
what color does L cones see?
red
what happens when multiple reflected surfaces are mixed?
the wavelengths they absorb are “subtracted” & only the wavelength that both colors reflect is reflected to the eye
what works for subtractive color mixing?
paint, ink, any opaque object
is color a physical property?
no
what is colors created by?
our perceptual system
where does the information from cones feed into?
neurons in the retina and lateral geniculate nucleus (LGN)
whats a problem with the trichromatic theory?
It cannot explain color afterimages and color blindness.
whats the opponent process theory?
information from cones feeds into opponent neurons in the retina and lateral geniculate nucleus (LGN)
what is recall in opponent-process theory?
on-center/off-surround & vice versa cells— it’s the same concept
what are examples of single opponent neurons?
+Red/-Green, +Green/-Red, +Blue/-Yellow, +Yellow/-Blue
what happens when a color opponent cell fires action potentials at a baseline rate?
the brain percieves achromatic (lacking color)
what happens if the action potential fires at a slower than baseline rate?
brain sees yellow
what happens if the action potential fires at a faster-than-baseline rate?
the brain perceives blue
where do cells react to color and spatial location?
in V1
what can happen if theres damage to LGN and V1?
cerebal achromatopsia (color blindness)
what influences color constancy?
local context/color constancy, individual differences
what does color constancy ensure?
that we perceive objects as the same color under varying illumination conditions (i.e., we know colors of objects dont change when different light hits them)
how are colors reflected?
reflected at a proportion of the light as it hits them, not a total amount of reflection; our brain makes adjustments
what is aging do to our lens?
yellows it and few people notice a difference due to our brain adapting the changes of wavelengths that hit the retina
what is a protanope retina?
color vision deficiency that has the absence of red cone photoreceptors, leading to difficulty in distinguishing between red and green hues.
how many cues is there to depth?
pictorial cues and movement cues
whats relative size?
two objects are the same size but if one object is larger than the other, it is closer
whats linear perspective?
parallel lines that extend into the distance appear to get closer to each other as they become further away
whats occlusion?
if one object partially blocks the view of another object, it is percieved as closer
whats elevation?
objects closer to the horizon and higher up are percieved asfurther away
what are shadows?
distance from shadows gives height perspective
whats object parallax?
objects closer in the visual field appear to move by faster than those that are further from us
do distant objects seem like they move?
no
what happens to objects closer to our fixation point?
Objects appear to be moving in the opposite direction from you
what happens to objects farther to our fixation point?
objects appear to move in the same direction as us
whats binocular disparity?
The difference in the images seen by each eye, which helps in depth perception.
what happens when we focus both of our eyes on an object (converge on an object)?
object falls on the same place on both of our retinas (fovea) and the images fuse so we dont see two
whats a horopter?
set of points in a visual scene that correspond to the same point on both retinas (given a fixation point)
what happens if we want to fuse an object that is not in our current horopter?
our eyes need to adjust (converge/diverge & accommodate)
whats accommodation of the thinning of the lens?
object is far
whats accommodation of the thickening of the lens (oculomotor)?
object is near
whats convergence of the lens (oculomotor)?
inward— object is near (thick)
whats divergence of the lens (oculomotor)?
outward; object is far (thin)
whats stereopsis?
The ability to perceive depth based on binocular disparity the visual information received by both eyes that gives us differently views of the world
whats a stereogram?
a single image that contains binocular depth information when viewed appropriately
what is size and depth reconstructed by?
our visual system; we can make errors
what happens to objects when they are surrounded by big objects?
they appear smaller
what happens to an object when its surrounded by smaller objects?
larger
whats the ponzo illusion?
A visual illusion where two horizontal lines appear different in length due to converging lines, typically making the upper line look longer.
what is size constancy?
objects that are the same size appear as the relative same size as us despite having a great variation in size on the retina with varying distance
what is the moon illusion: size constancy?
when the moon is at the horizon, linear perspective tells us its further away and larger (brain using less info about distance)
when the moon further from the horizon, depth cues tell us its cloer and smaller
what is the moon illusion: size contrast?
when the moon is at the horizon, it seems large relative to the smaller trees and buildings
when the moon is in the sky, its size seems smaller relative to the larger sky
what is the moon illusion: oculomotor cues?
when. the moon is at the horizon, our eyes focus on it through convergence & accommodation (eye lens thickens); looks bigger
when its in the sky, our eyes have difficulty focusing on it so it stays on a default level; looks smaller
