Sensory Perception

Question 1

Binocular Cues

Answer 1

humans have two eyes which allow them to receive visual cues from their environment giving them a sense of DEPTH

Question 2

Retinal Disparity

Answer 2

a binocular cue; eyes are about 2.5 inches apart, allowing humans to gain slightly different views of objects in the world

Question 3

Convergence

Answer 3

a monocular cue; gives humans an idea of depth as well as how much their eyeballs have turned

• muscles of the eyes are relaxed when things are far away
• muscles of the eyes are contracted when things are close by

Question 4

Monocular Cues

Answer 4

visual cues that can be received without the need for two eyes; give humans a sense of FORM

Question 5

Relative Size

Answer 5

a monocular cue; the closer the object, the larger it is perceived

Question 6

Interposition (Overlap)

Answer 6

a monocular cue; perception of an object in front of another; object that is in front is closer

Question 7

Relative Height

Answer 7

a monocular cue; things higher are perceived to be farther away than things lower

Question 8

Shading and Contour

Answer 8

a monocular cue; using light and shadows to perceive form

• depth = crater
• contour = mountain

Question 9

Motion Parallax

Answer 9

a monocular cue; gives us a sense of MOTION; things further away move slower whereas things closer by move faster

Question 10

Constancy

Answer 10

perception of object doesn’t change even if the image cast on the retina is different

• size constancy = one may appear larger if its closer, but we still think of it being same size
• shape constancy = changing shape maintains same shape perception
• color constancy = despite changes in lighting which change the image color falling on your retina, we understand that the object is the same color

Question 11

Sensory Adaptation

Answer 11

our senses are adaptable and they can change their sensitivity to stimuli

Question 12

Hearing Adaptation

Answer 12

when there is a higher noise, the inner ear muscle contracts dampening vibrations in the inner ear and protecting the ear drum
-takes a few seconds to kick in and therefore, if there is a immediate gunshot, it does not work

Question 13

Touch and Smell Adaptation

Answer 13

• touch = temperature receptors desensitized over time

- smell = desensitized receptors in your nose to molecule sensory information over time

Question 14

Proprioception Adaptation

Answer 14

sense of the position of body in space (“sense of balance /where you are in space”)
-Experiment - goggles that make everything upside down but eventually you would be able to accommodate and flip the view back over

Question 15

Sight Adaptation

Answer 15

whereas other adaptations, sight has possibility for both down and up regulation

• Down Regulation - when it is bright out, the pupil will constrict, restricting the amount of light that can hit the retina; the rods and cones are desensitized
• Up Regulation - dark regulation; pupils dilate and the rods and cones start synthesizing light sensitive molecule

Question 16

Just Noticeable Difference (JND)

Answer 16

threshold at which you are able to notice a change in any sensation (50% of the time); you can’t tell difference between 2 and 2.02 lb weight but can tell difference between 2 and 2.2 lb weight

Question 17

Weber’s Law

Answer 17

∆I/I = k where ∆I is the JND, I is the initial intensity of stimulus, and k is a constant
-Linear relationship between ∆I (incremental threshold) and I (background intensity) = slope is k

Question 18

Absolute Threshold of Stimulation

Answer 18

minimum intensity of stimulus needed to detect a particular stimulus 50% of the time

• the 50% accounts for the fact that at low levels of stimulus, some subjects can detect and others can’t; there are also individual differences
• not a fixed unchanging number
• can be influenced by: expectations, experience, motivation and alertness

Question 19

Subliminal Stimuli

Answer 19

stimuli below the absolute threshold of sensation

Question 20

Somatosensations

Answer 20

different types of somatosensation which are dependent on Intensity, Timing, and Location

Question 21

Types of Somatosensations

Answer 21

• Temperature = thermoception
• Pressure = mechanoception
• Pain = nociception
• Position = proprioception

Question 22

Intensity

Answer 22

how quickly neurons fire for us to notice

• Slow = low intensity
• Fast = high intensity

Question 23

Timing

Answer 23

neuron encodes 3 ways for timing:

• Non-Adapting = neuron consistently fires at a constant rate
• Slow-Adapting = neuron fires in beginning and calms down as time passes
• Fast-Adapting = neuron fires as soon as stimulus starts…then stops firing; fires again when stimulus ends

Question 24

Location

Answer 24

location-specific stimuli by nerves are sent to the brain; relies on dermatomes

Question 25

Vestibular System

Answer 25

a type of sensation focused on balance and spatial orientation; comes from both the inner ear and limbs

Question 26

Inner Ear

Answer 26

semicircular canals with components posterior, anterior, and lateral which are orthogonal to each other

Question 27

Endolymph

Answer 27

fluid that fills the semicircular canal; when we rotate, the fluid shifts which allows us to detect which direction our head is moving in, and because we can detect how quickly the endolymph is moving, we can determine the strength of the rotation

Question 28

Otolithic Organs (utricle and saccule)

Answer 28

filled with calcium carbonate crystals which aid in detection of linear acceleration and head positioning; when we move someway, the crystals pull on hair cells triggering an action potential; would not work very well without gravity or with buoyancy
-dizziness or vertigo may result from endolymph still spinning when you’re not

Question 29

Signal Detection Theory

Answer 29

looks at how we can make decisions under conditions of uncertainty–discerning between important stimuli and unimportant “noise”; at what point can we detect a signal

Question 30

Hit/Miss/False Alarm/Correct Rejection

Answer 30

• hit = subject responded affirmative when signal was present
• miss = a negative response to a present signal
• false alarm = subject perceived a signal when there was none present
• correct rejection = a correct negative answer for no signal

Question 31

Strength and Strategy

Answer 31

d’ = Strength
-hit > miss (strong signal)
-hit < miss (weak signal)
c = Strategy
-Conservative - always say no unless 100% sure that signal is present; bad thing is might get some misses
-Liberal - always say yes; get some false alarms

Question 32

Signal Distribution

Answer 32

• x-axis = intensity
• difference between means of noise distribution and signal distribution is d’, where larger value = strong signal
• Strategy C can be expressed as what threshold the individual deems necessary for them to say yes
• -> B = pick an intensity and something above is yes and anything below is no
• -> D = d’ - B
• -> C = conservative; B - (d’/2); C = 0 ideal (C < 0 liberal; C > 0 conservative)
• -> Beta = value of threshold is ratio of height of signal to height of noise distribution (ln beta = d’ * C)

Question 33

Bottom Up Processing

Answer 33

begins with stimulus; stimulus influences our perception

• no preconceived cognitive constructs of the stimulus (never seen it before)
• data driven; stimulus drives cognitive awareness of what you’re looking at
• inductive reasoning; always correct

Question 34

Top Down Processing

Answer 34

uses background knowledge to influence perception (example is looking for Waldo)

• theory driven; perception influenced by our expectation
• deductive reasoning
• not always correct

Question 35

Gestalt Principles

Answer 35

tries to explain why we perceive things the way we do

Question 36

Similarity

Answer 36

items similar to one another are grouped together by the brain
-ex = brain automatically organizes squares and circles in columns and not rows

Question 37

Pragnanz

Answer 37

reality organized in the simplest form
-ex = when looking at the Olympic rings, the brain looks at them as 5 circles instead of thinking of them as complex shapes

Question 38

Proximity

Answer 38

objects that are close together, we naturally group the closer things together than those that are far apart

Question 39

Continuity

Answer 39

lines are seen as following the smoothest path

Question 40

Closure

Answer 40

objects grouped together are seen as a whole; mind fills in the missing information
-ex = you fill in triangle even when there is none

Question 41

Symmetry

Answer 41

the mind perceives objects as being symmetrical and forming around a center point

Question 42

Law of Common Fate

Answer 42

if there are an array of dots and half of them were moving up and the other half were moving downward, we would perceive the upward moving dots and downward moving dots as two distinct units

Question 43

Law of Past Experiences

Answer 43

under some circumstances, visual stimuli are categorized according to past experiences
-ex = if an individual reads an English word they’ve never seen before, they use the law of past experiences to interpret the letters “L” and “I” as two letters beside each other rather than interpreting them as a “U” using the law of closure

Question 44

Contextual Effects

Answer 44

the context in which stimuli are presented and the processes of perceptual organization contribute to how people perceive those stimuli (and the context may also establish the way stimuli are organized)