Sensation and Perception Flashcards
What is sensation?
process by which sense organs gather information about the environment and transmit it to the brain
What is perception?
process by which the brain selects, organizes, and interprets sensations
What is transduction?
translation of physical energy into electrical signals
What is bottom-up processing?
starts with raw sensory data that feed up to the brain
listening to a song for the first time
What is top-down processing?
starts with observer’s expectations and knowledge
listening to a song for the 100th time
What are absolute thresholds?
- minimal amount of stimulation that can be detected
- Occurs when person can detect signal 50% of the time
What are difference thresholds?
lowest level of stimulation required to sense that a change in stimulation has occurred
What is the jnd?
smallest difference in intensity between 2 stimuli that person can detect (same as difference threshold)
What is Weber’s law (fraction)?
for 2 stimuli to be perceived as different in intensity, the second must differ from the first by a constant proportion
What is signal detection theory?
-Sensation is not a passive process
-Experiencing a sensation means making a judgment
-Detection depends on:
~Sensitivity
~Response bias
What is response bias?
person’s readiness to report detecting a stimulus
What is a hit?
A response is given and a signal is present.
What is a miss?
A response is not given but a signal is present.
What is a false alarm?
A response is given but a signal is not present.
What is a correct rejection?
A response not is given and a signal is not present.
What factors affect response bias?
Expectations -
Motivation-
What is sensory adaptation?
Tendency of sensory systems to respond less to stimuli that continue without change
What is the Gestalt approach?
the whole is greater than the sum of its sensory parts
What is figure-ground perception?
we inherently distinguish between figure and ground
What are the grouping principles?
Proximity, Similarity, Continuity, and Closure
What is proximity?
we tend to group together objects that are close to one another
What is similarity?
we tend to group together objects that are similar to one another
What is continuity?
brain organizes stimuli into continuous lines or patterns
What is closure?
we tend to perceive incomplete figures as complete
What are binocular and monocular cues for depth?
binocular - Each eye has slightly different view of same scene
monocular - can only use one eye
What is retinal (binocular) disparity?
images produce different image on each retina
What is convergence?
- turning inward of eyes toward nearby object
- Closer object -> greater convergence
What is relative size?
when something is smaller, we perceive it to be farther away
What is perceptual constancy?
organization of changing sensations into perception that is relatively stable in size, shape, and color
What is color constancy?
tendency to perceive color of objects as stable despite changing illumination
What is shape constancy?
perception that object’s shape remains constant despite changing shape of retinal image
What is size constancy?
perception that the size of objects remains constant despite different sizes of images on retina
