Chapter 4 - sense of vision Flashcards
6-15
What’s the scientific word for light?
electromagnetic radiation!
Do wavelength and frequency mean the same thing?
Yes!
light = wavelength sound = frequency
What does the amplitude of light signify?
the brightness of a color.
What does the wavelength of light signify?
the color.
What is visual acuity?
detailed vision!
define cornea:
provides protection from damage.
define pupil:
dark opening in the eye through which light passes.
define iris:
colored part which changes the size of the pupil to let in more or less light.
define lens:
focuses light onto back of eye.
define retina:
sheet of tissue at back of the eye containing visual processing cells that convert light to neural impulses.
What is accommodation?
automatic adjustment of the lens of the eye for seeing at different distances.
What are the two types of retinal neurons?
cones & rods!
define cones and rods:
rods: perceives light and dark.
cones: perceives color and detail.
What is dark adaptation?
exposure to darkness causes eyes to become more sensitive, allows for better vision in the dark.
What is the trichromatic theory?
theory that color vision arises from the combinations of neural impulses from three different kinds of sensors (cones).
CONES:
red (long), green (_____), blue (_____)?
red(long), green(medium), blue(short).
What is color deficiency?
when you are born without one or more types of cones.
What is the color opponent system?
if a color is present, it causes cells that register it to inhibit the perception of the complementary color.
What is afterimages?
images left behind by a previous perception.
What are the 3 opposing pairs?
red & green.
blue & yellow.
black & white.
What are feature detectors?
cells that respond to only one specific visual stimulus
ex. angles, horizontal lines, close objects, far objects.
What is perceptual constancy?
perception of characteristics that occurs when an object or quality, looks the same even though the sensory information striking the eyes changes.
ex. size, shape, or color.
info. ^^^^ not born with these 3.
What is depth perception?
ability to use the two-dimensional image projected on the retina to perceive three dimensions.
How many types of visual cues are there for depth perception?
three types!
A: Monocular cues
A: Binocular cues
A: Pictorial depth cues?
monocular cues:
for distance can be picked up with one eye.
binocular cues:
cues to distance that arise from both eyes working together. (20ft or less).
info. closer image, greater disparity (difference) between both images.
binocular disparity:
has to do with each individual image.
convergence:
has to do with position of eyes and angle of their focus.
pictorial depth cues:
drawing depth perception into artwork.
motion parallax:
having images of objects at different distances moving across the retina at different rates.
ex. in a car, close stuff fly by, far things go slowly.
accommodation:
covered earlier in lecture.
What’s the difference between change blindness and inattentional blindness?
change blindness: when people fail to detect changes to visual details of a scene.
inattentional blindess: failure to perceive objects that aren’t the focus of attention.
