sensation and perception

Question 1

what is the difference between bottom-up and top-down processing?

Answer 1

bottom-up: starts with raw sensory data that gets communicated to the brain (we have no pre-existing beliefs about what we’re observing)
top-down: starts with observer’s expectations and knowledge (we already have a notion of the thing we are interpreting) (ex: if you see the chair you have stubbed your toe on before and you avoid it to make sure it does not happen again.)

Question 2

what are absolute thresholds?

Answer 2

minimal amount of stimulation that can be detected half of the time (ex: hearing test where you hear those high pitch frequencies)

Question 3

what are difference thresholds (the jnd)?

Answer 3

smallest difference in intensity between 2 stimuli that a person can detect. (ex: if you turn up a sound and can barely hear the difference or not)

Question 4

what is signal detection theory?

Answer 4

perception of a stimulus is not solely determined by the strength of the signal itself. it also depends on the individual’s sensitivity to the signal and their decision-making processes.

Question 5

what is sensory adaptation?

Answer 5

a decrease in sensitivity to a constant level of stimulation (ex: putting a bracelet and forgetting it was on your wrist after a while cause you got used to it)

Question 6

what is the Gestalt approach (overall – not specific principles such as figure-ground)?

Answer 6

we perceive objects as whole rather than as a sum of the individual parts

Question 7

what is perceptual constancy?

Answer 7

the ability of the human brain to maintain a consistent perception of an object’s properties, such as size, shape, color, and brightness, despite changes in the sensory input.