Topic 4

Question 1

Prosopagnosia

Answer 1

Sensing & perceiving are connected but different

Cognitive disorder of face

perception

Difficulty perceiving/recognizing faces

Face blindness

Intact vision

Question 2

Sensation

Answer 2

Detection of physical energy by the sense organs

Question 3

Perception

Answer 3

The brain’s interpretation of raw sensory data

Question 4

Sensory receptors

Answer 4

Specialized neurons that respond to different types of stimuli

Our sensory systems provide information about our surroundings, allowing us to navigate and interact with our environment.

Photoreception: light

Mechanoreception: pressure, vibration, movement

Chemoreception: chemical

Question 5

Transduction

Answer 5

Conversion of one energy form into another

Receive sensory information via sensory receptor cells

Transform the stimulation into neural impulses (action potentials)

Deliver the neural information to the brain

Question 6

The multitasking brain

Answer 6

Bottom-up:
* Perception based on building simple input into more complex perceptions\

Top-down:
* A perceptual process in which memory and other cognitive processes are required for interpreting incoming sensory information

Question 7

Sensory adaptation

Answer 7

Activision is highest at first detection, then sensory adaptation occurs

Sensory receptor cells become less responsive to a stimulus that is unchanging, becomes less noticeable

Adaptive - conserve energy, focus on novelty & changes

Question 8

Psychophysics

Answer 8

The measurement of sensation

Sensation begins with a detectable stimulus

Absolute threshold:
* Minimum intensity of a stimulus that a person can detect half the time

Question 9

Subliminal perception

Answer 9

Perception of stimuli that are presented at below absolute threshold

Perception != persuasion, little practical application

Question 10

Just noticeable difference (JND)/Difference threshold

Answer 10

The degree of difference that must exist between two stimuli before the difference is detected:
* Many decisions rely on our ability to detect small differences

Weber’s law:
* JND between 2 stimuli is not an absolute amount, but an amount relative to the intensity of the first stimulus
* The more intense the initial stimulus the larger the difference needs to be

Question 11

JND & Marketing

Answer 11

JND applies to what we buy

Marketers are concerned that:
* Positive changes are discernible (at or just above JND)
* Negative changes are not discernible (below JND)
* Changes subtle enough to keep current customers

Question 12

The role of attention in S&P

Answer 12

Flexible attention is critical

Selective attention:
* Focusing on a specific aspect of sensory input while ignoring other stimuli in the environment
* Attention as a bottleneck
* The other channels are still being processed at some level

We are poor at detecting stimuli in plain sight if our attention is focused elsewhere

Inattentional blindness
* Failure to detect an unexpected stimulus in plain sight
* Limited attentional resources, focus on what we deem important

Change blindness
* Failure to detect changes in your environment
* Limited resources further constrained by age, distraction

Question 13

Vision

Answer 13

Stars with light, the physical energy that stimulates the eye

• Transduction: photoreceptors (rods & cones)

Question 14

The eye

Answer 14

The eye
* Muscle ring that controls pupil size
* Controls the amount of light entering the eye

Cornea
* Light enters through the cornea, passes through the pupil, and hits the lens
* The lens focuses light rays into an image on the retina of the eyeball

Retina
* The light-sensitive back inner surface of the eye - nerve cells here
* Contains rods & cons

Optic nerve
* Carries neural impulses from eye to brain
* Blind spot: the point where the optic never leaves the eye no receptor cells

Question 15

The eye: visions window

Answer 15

Iris’s main job is controlling the light that enters but also:
* The eye adjusts to imaginary light
* Iris constricts with disgust or when you are about to say “NO”
* Dilates with romance or trust (autonomic arousal)

Question 16

Rods & cones

Answer 16

Retainal receptors

Rods:
* 100 - 125 mil
* Detect black, white, and gray and are sensitive to movement
* Peripheral & twilight vision
* Low light situations
* Located in peripheral

Cons
* 5 - 6 mil
* Shap focus colour perception, detail

Question 17

Vision: how we percicve shape and contour

Answer 17

Feature detectors:
* Cells in the visual cortex that respond are sensitive to specific features of Env’t

Some cells respond to lines in specific orientations:
* Simple cells - lines, angles

Some cells respond to particular shapes

Question 18

Color vision

Answer 18

Different theories of color perception

Trichromatic theory
* The retina contains red, green & blue receptors - when stimulated, these receptors can produce the perception of any color
* Consists of three types of corners in the eye

Opponent process theory:
* We perceive colors in terms of three pairs of opponent colors: red or green, blue or yellow, and black or white

Color processing combines the trichromatic theory and the opponent processing theory

Two stages
* The retina’s red, green, and blue cones respond in varying degrees to different color stimuli
* The cone’s responses are processed by opponent-process cells

Question 19

When we can’t see

Answer 19

Blindness can result in the reorganizing of other sensory cortices and changes in other senses

Echolocation might improve following blindness

Visual agnosia:
* Object recognition deficit
* Damage to higher visual cortical areas

Blindsight:
* Above chance visual performance and cortically blind individuals with damage to area V1

Question 20

Perceptual organization

Answer 20

How do we organize and integrate sights so they become meaningful perceptions

Perception is a constructive process We go beyond the stimuli that are presented to construct a meaningful situation

We don’t passively respond to visual stimuli that fall on the retina, we actively try to organize and make sense of what we see

Question 21

Gestalt principle

Answer 21

Principles that determine how we organize information into meaningful wholes

We both with built tendencies to organize incoming sensory info into certain ways

Question 22

Perceptual constancy

Answer 22

The recognition that objects are constant and unchained even though sensory input about them is changing

Question 23

Colour constancy

Answer 23

The ability to perceive an object as having relatively the same color under varying illumination conditions

Illusion can occur when this adjustment leads to a misperception of color

Question 24

How do we perceive depth?

Answer 24

Monocular depth:
* Cues rely on one eye
* Relative size
* Texture gradient
* Overlap
* shading
* Height in field of view
* Liner perspective

Question 25

Hearing

Answer 25

Sound :
* Is the movement of air molecules brought about by the vibration of an object

The physical aspect of sound:
* Frequency = pitch (Hz)
* Amplitude = loudness (dB)

Question 26

Sensing sound

Answer 26

The outer ear (pinna):
* Reverse megaphone - funnels sound in toward eardrum

Eardrum (aka Tympanic membrane):
* Part of the ear that vibrates when sound waves make contact
* Transmits vibrations to middle ear

Middle ear:
* Tiny chamber containing 3 tiny bones (stirrup, anvil, hammer) that act as a mechanical amplifier

Cochela:
* Colid tube in the ear is filled with fluid that vibrates in response to sound

Basilar membrane:
* Runs through the center of the cochlea - divided into two chambers, covered wit hair cells

Hair cells:
* Tiny cells that are bent by vibration - transmit neural messages (transduction happens here)

Question 27

Sociocultural influences on auditory perceptions

Answer 27

Culture & social life provide a framework for the interpretation of stimuli

Since wave speech experiments - what people hear depends on expectations

Question 28

The multitasking brain

Answer 28

Bottom-up processing:
* Begins with sensory receptors
* We sense the basic features of stimuli and integrate them

Top-down processing:
* Guided by higher-level mental processes
* Previous experience and expectations are used to interpret what sense detect

Question 29

Perceptual sets

Answer 29

Predisposition or readiness to perceive something in a particular way (top - down influence)

Experience, expectations, emotions etc.

Question 30

Context effects on perception

Answer 30

Urecall your own perceptions in different contexts

Context helps form perception and interpretation of a situation

Question 31

Emotions can sway our perceptions

Answer 31

Sad music predisposes us to perceive sad meanings (mourning vs. morning)

Anger increases likelihood that neutral items will be mistaken as a weapon

Worrying about panic leads to interpreting physical sensations as panic

Question 32

Motives & perception

Answer 32

Desired objects seem closer when motivated

Closeness can increase desire

Question 33

Bias & perceptions

Answer 33

Children as naive, and innocent, afforded certain protections

Perceptions of age can be influenced by race

264 university students involved in the study

Overestimated the age of Black children by 4.5 years (i.e., 12 à 16-year-old)

Black children over the age of 10 are judged as significantly “less innocent” than white children of the same age.

Associated with anti-Black prejudice & dehumanization

Question 34

Cross-talk between senses

Answer 34

Many examples:
* McGurk effect
* Rubber hand illusion

Synesthesia:
* Stimulation of one’s sense evokes another
* Sounds with color, colors with taste