sensation and perception - vision Flashcards
perceptual process
- the tendency to experience something in a particular way.
3 types:
i) experienced with vision (reversible figures)
(ii) hearing (“stuffy nose” vs “stuff he knows”)
(iii) taste
name and explain the 2 theories in colour vision theory
- trichromatic theory
- occurs in early processing
- colour mixing occurs through neural activity.
- some are tetrachromats
- the human vision has 3 types of cones: sensitivity to red, green, and blue wavelengths.
red = long wave
blue= short wavelength
green = medium wavelength
- opponent process theory
- explains complimentary afterimages.
- occurs in later processing
- receptors make opposing responses to 3 pairs. (he visual system respond to opposing pairs of colors: red vs. green, blue vs. yellow, and black vs. white. These receptors can only signal one color of a pair at a time, meaning when one is activated (e.g., red), the other (green) is suppressed.)
name the 2 ideas in sight and the brain
bottom up processing: stimulus elements are detected and assembled bled into complex forms.
- ex: when you see a new puzzle for the first time; you start by examining each piece’s colors and shapes, then gradually fit them together to create the complete image without knowing what the final picture looks like.
top down processing: perception is guided by prior knowledge, experiences, and expectations, allowing us to interpret sensory information based on what we already know or expect to see.
-ex:”I l_ke to eat ice cream”) and are still able to understand it because your brain fills in the gaps based on your previous knowledge of the words and context.
what is the system name for how the sight is received in the brain
the visual system
in perceptual process, what does it mean by “attention shapes perception?”
2 points to this idea:
- change blindness - the difficulty recognizing an obvious change in environment
- inattention blindness - the difficulty recognizing unexpected change.
name and describe the 6 types of colour blindness
- monochromatic
- can only see black and white (achromatopsia) - trichromatic
- red, green, and blue receptors all “work”
- the normal vision - protanopia
- red receptors do not function
- cannot see red - deutranopia
- green receptors do not function
- cannot see green - titranopia
- blue receptors do not work
- cannot see blue - dichromats
- can only see 2/3 cone cell colours.
-can see either red and blue, red and green, or green and blue, but cannot distinguish all three primary colors—red, green, and blue—together, limiting their color perception.
name the 5 gestalt principles
- proximity principle
- things that are near one another seem to belong together. - similarity principle
- people tend to group stimulus that are alike - continuity principle
- people tend to connect point that result in a straight/gently curved line (our mind wants to see things as a whole as opposed to breaking parts apart) - closure principle
- people tend to ignore gaps or figures to create a sense of closure or completeness - simplicity principle
- people tend to organize and interpret forms in the simplest way possible.
what is the phi penomenon
animated motion in a film or video, where a series of still images are shown in rapid succession, creating the illusion of smooth movement, like a character walking
- think of a flip book
explain the figure and ground theory
Figure and ground theory explains how we distinguish objects (figures) from their backgrounds (ground),
- as seen in the vase-and-faces image.
(wherever we are directing our attention to is the figure and everything else is the background)
explain proximal vs distal stimuli
Proximal stimuli are what our senses detect, like the picture of a tree our eyes see, while distal stimuli are the real objects around us, like the actual tree outside. - This difference helps us understand how things can look different based on distance and lighting.
explain perceptual hypothesis
a guess about what we perceive based on prior knowledge, such as thinking a blurry shape in a park is a dog based on past experiences.
explain depth perception
cue that interprets an objects distance.
2 types:
1. binocular cues
- retinal disparity: increased disparity pairs with increased closeness:
ex: hold your finger in front of your face and look at it with one eye closed, then switch to the other eye; the finger appears to shift position against the background, demonstrating how the brain uses the difference in views from each eye to perceive depth.
- convergence: the closer the object is, your eyes focus on that object. ex: cross-eyed when looking at your nose.
- monocular cues
- motion parallax: objects at different distances move across the retina at different rates. ex: a passenger in a a car will see that closer objects move by faster
- pictorial depth cues: 6 types!
name the 6 pictorial cues
- linear perspective
- texture gradient
- interposition
- relative size
- height in plane
- light and shadow
explain linear perspective
- straight lines look like they converge
ex: when driving, the road lines look “closer”
explain texture gradient
things that are further look less distinguishable
- when looking at a land full of flowers, the further flowers are less distinguishable.
