Exam 3 (Chapter 5) Flashcards
def of perception
- interpreting sensations
- help sensations become meaningful
psychophysics
- measure perception
- concerned with 2 types of thresholds
2 types of thresholds
- Absolute
2. Difference
absolute threshold
-min amount of energy/stimulus perceived 50% of the time
difference threshold
- distinguish between stimuli rather than levels
- just noticeable difference (JND)
perceptual organization
- task performed by perceptual system
- determines what goes together to form an object
principles of organization
- two main principles
1. Figure ground
2. Grouping
figure ground
-organize stimuli into central figure then against background
grouping
putting similar things into groups
principles of grouping (4)
- proximity
- similarity
- continuity
- closure
closure grouping
filling in missing spaces to form complete object
perceptual constancy
- allows us to recognize familiar stimuli under varying conditions
- see things as same even though they are changing
perceptual constancies (3)
- size
- shape
- brightness/colour
size constancy
-seems like it changes due to distance
shape constancy
shape remains same even when we see it in different angles (ex. Frog in class)
brightness/colour constancy
color remains same but looks different under different lights (ex. car paint, see rainbow)
2 types of depth perception cues
- binocular
2. monocular
binocular cues
- eye convergence
- retinal/binocular disparity
eye convergence cue
- produced by feedback from muscles
- being cross eyed
retinal/binocular disparity
-each eye sees different image (different angle)
monocular cues
- pictorial
- non pictorial
pictorial cues (5)
- linear (parallel lines connect)
- interposition (objects closer cut off view of distant objects)
- elevation (seems as things are higher if distant)
- texture gradient (closer objects have more detail)
- relative size (smaller objects are further away)
non pictorial cues
-motion parallax (if moving, nearer objects look faster (passing train)
apparent motion (2 parts)
- stroboscopic illusion
2. autokinetic illusion
stroboscopic illusion of motion
- when we see slightly different images
- slightly displaced lights flash in rapid succession
- Ex. strobe lights
auto kinetic illusion of motion
- perceived motion by stationary object
- Ex. stand in dark room and look at ball of light, light will seem to move because muscles in eye are moving
webers law
-smallest detectable difference in stimulus energy is constant fraction of intensity of stimulus
fechners law
-great magnitude of stimulus = bigger change needed for JND
