3.5 Perception

Question 1

hearing loss

Answer 1

loud sounds mechanically harm hair cells

they never regrow

smallest hair cells go away first, high-frequency goes away first

Question 2

absolute threshold (of perception)

Answer 2

the minimum stimulus intensity needed to activate a sensory receptor 50% of the time

Question 3

JND (difference threshold)

Answer 3

just noticeable difference - the minimum noticeable difference between any two sensory stimuli 50% of the time

the magnitude of the initial stimulus is important: think weights

“JND Weights”

Question 4

weber’s law

Answer 4

w/ respect to JND, there is a proportion necessary to determine the JND

weight: 2%
lights: intensity 8%
tones: 0.3% frequency

Question 5

signal detection theory

Answer 5

how will somebody detect a signal amidst all background noise

4 possibilities: hit (true positive), miss (false negative), false alarm (false positive), and correct rejection (true negative)

Question 6

Gestalt

Answer 6

“form” or “shape”

the whole is more than the sum of its parts. kinds include:

1. Emergence
2. Figure/ground
3. Multistability
4. Gestalt laws of grouping

E Fg M Glog

Question 7

Emergence

Answer 7

the whole comes first from an outline, then we identify its parts (the blotches of black and white make up a dog)

Question 8

Figure/ground

Answer 8

a perception of a thing, we tend to separate a figure from everything else (background)

e.g. we can’t see both the vase and the faces concurrently

Question 9

Multistability

Answer 9

the tendency of ambiguous objects to pop back and forth unstably between alternative interpretations in our brains

Question 10

Gestalt laws of grouping

Answer 10

5 laws:

1. Law of proximity
2. Law of similarity
3. Law of continuity (the law of good continuation) - good for overlapping figures (two circles overlapping)
4. Law of closure - our brains fill in the gaps
5. Law of common fate - things moving together are seen as a unit
6. Law of connectedness - things joined or linked or group are perceived as connected

Question 11

Bottom-up processing

Answer 11

“data-driven processing”

the sensory input is “bottom”, the identifiable image in the brain is the “top”

Useful when we aren’t familiar with the stimulus

Question 12

Top-down processing

Answer 12

experience and expectations are used to interpret sensory information

occurs with familiar stimuli