Chapter 4: Sensation and Perception

Question 1

Psychophysics

Answer 1

study of the relationship between physical stimuli and sensation they evoke in human body

Question 2

Transduction

Answer 2

The senses transduce physical energy into neural signals
that are sent back to the brain for further processing

Question 3

Sensations

Answer 3

neural information detection in the brain from
the sensory organs (eye, ear, etc.)

Question 4

where does perception happen

Answer 4

Realizing that we are seeing or hearing takes place at
brain, and not sensory organs

Question 5

Data Reduction System

Answer 5

selecting and analyzing only most important data by the brain (we do not process everything)

Question 6

Sensory adaptation

Answer 6

change in sensory receptor responsiveness towards unchanging stimuli e.g. pressure from wearing a watch

Question 7

Absolute threshold

Answer 7

the minimum amount of physical energy necessary to produce a sensation

Question 8

Difference threshold

Answer 8

the minimal difference between two stimuli required before the two stimuli can be coded as different

Question 9

Sensory analysis

Answer 9

the process by which the senses divide the world into important perceptual features e.g. lines, shapes, color

Question 10

Weber’s Law

Answer 10

Principle that two stimuli must differ by a minimum percentage to be perceived as different – depends on intensity too

Question 11

Subliminal Perception

Answer 11

Detection of information below level of conscious
awareness

Question 12

Subliminal Perception uses

Answer 12

To suggest or influence

Question 13

Synaesthesia

Answer 13

One sense induces experience in another sense

Question 14

Phantom Limb Pain

Answer 14

Experiencing sensations in a limb that does not exist
Occurs among amputees

Question 15

Extrasensory perception (ESP)

Answer 15

• Perception in absence of concrete sensory input

Question 16

Light

Answer 16

a form of electromagnetic radiation (aka electromagnetic wave
or energy) that is detected by the eye

Question 17

Wavelength

Answer 17

– determines the nature of light i.e. hue or color. As an
example, red light has a different wavelength as compared to blue light

Question 18

Amplitude

Answer 18

– tells us the intensity or brightness of the light

Question 19

Structure of Eye

Answer 19

sclera, retina,iris,cornera,pupil,Lens

Question 20

Sclera

Answer 20

• White, outer part of eye
• Helps maintain shape of eye
• Protects eye from injury

Question 21

Iris

Answer 21

Coloured circular muscle that controls entering
amount of light

Question 22

Pupil

Answer 22

Opening in center of iris through which light passes
* Size controlled by muscles in iris

Question 23

Cornea

Answer 23

Transparent membrane covering front of eye

Question 24

Lens

Answer 24

Transparent, somewhat flexible, disk-like structure

Question 25

Retina

Answer 25

The multilayered, light-sensitive surface at the back of the eye * Converts visual stimuli to neural impulses

Question 26

Photoreceptors> Rods,Cones

Answer 26

Cells on the retina which convert electromagnetic energy into electrochemical impulses – to be read by the brain

Question 27

Rods

Answer 27

Photoreceptors for dim light * Only produce black and white * Function well under low illumination

Question 28

Cones

Answer 28

Photoreceptors for colors and bright light *Require more light than rods

Question 29

Fovea

Answer 29

Tiny area in the center of the retina at which vision is best * Highly dense with cones; rods absent

Question 30

Blind spot

Answer 30

Place on retina containing neither rods nor cones * Where the optic nerve leaves eye

Question 31

Colour Vision Theories

Answer 31

Trichromatic theory Opponent process theory

Question 32

Trichromatic theory

Answer 32

The trichromatic theory that states we have 3 types of cones of varying lengths; red, green, and blue (sensitive to different wavelengths)

Question 33

Opponent process theory

Answer 33

Opponent process theory: color vision theory based on three “systems”: red vs green, blue vs yellow, black vs white * Exciting one color in a pair (red) blocks the excitation in the other member of the pair (green)

Question 34

After Image Effect

Answer 34

Fatigue caused by one response, will produce afterimage of the opposite colour

Question 35

Colour blindness

Answer 35

– inability to perceive colours due to lacking or faulty cones

Question 36

Sound

Answer 36

vibrations/rhythmic movements in the air that are captured by the auditory system

Question 37

Structure of Ear

Answer 37

3 main parts – outer, middle & inner

Question 38

Outer

Answer 38

Outer – External part of ear that collects and channels sound

Question 39

Middle

Answer 39

Middle – Channels sound to inner ear

Question 40

Inner

Answer 40

Inner – Converts sound into neural impulses i.e. hair receptor cells within the cochlea that transduce vibrations

Question 41

Frequency Theory

Answer 41

As pitch rises, nerve impulses of a corresponding frequency are fed into the auditory nerve e.g. 800-hertz tone produces 800 nerve impulses a second

Question 42

Place theory

Answer 42

Place theory – Higher and lower tones excite specific areas of the cochlea e.g. higher tones are registered most strongly at the base of the cochlea

Question 43

Skin

Answer 43

Touch (pressure), temperature (hot/cold), pain * Each with own specific receptors in the skin

Question 44

Chemical Sense

Answer 44

Taste – sweet, salty, sour, bitter, umami (receptors in tongue) * Smell – receptors in the Olfactory Epithelium (roof of nasal cavity)

Question 45

Kinesthetic

Answer 45

– information on movement (kinesthesia) and bodily position (proprioception) Muscle memory e.g. in playing sport & walking without looking at feet

Question 46

Vestibular

Answer 46

balance and orientation – semicircular canals (ear as an organ of balance and not just hearing) * Motion sickness or dizziness – senses from eyes & ears don’t match up (sensory conflict theory)

Question 47

How sensations are organized into meaningful patterns

Answer 47

Pre-existing ideas and expectations guide our interpretations

Question 48

Bottom-Up Processing

Answer 48

Bottom-up processing: analyzing information starting at the bottom (small units i.e. your senses) and going upward (to the brain) to form a complete perception

Question 49

Top-Down Processing

Answer 49

Top-down processing: pre-existing knowledge in mind that is used to rapidly organize features into a meaningful whole

Question 50

Gestalt Principles of Organisation

Answer 50

change in focus also changes our attention towards other objects

Question 51

Ambiguous stimuli

Answer 51

Ambiguous stimuli: patterns allowing more than one interpretation e.g.Rorschach test

Question 52

Size & Shape Constancy

Answer 52

Perceived size and shape remains constant despite changes in retinal image

Question 53

Inattentional blindness

Answer 53

failure to perceive a stimulus that is in plain view but not the focus of attention e.g. driving accidents

Question 54

Relative size

Answer 54

if two objects of the same size appear at different distances, the distant object looks smaller

Question 55

Light and shadow

Answer 55

most objects are lit in ways that create clear patterns of light and shadow, resulting in a three-dimensional appearance e.g. 3D drawings

Question 56

Overlap

Answer 56

when one object partially blocks another, it appears to be closer

Question 57

Perceptual habits

Answer 57

ingrained patterns of organization and attention – perceiving things as they usually are e.g. laptop model (Microsoft vs Apple)

Question 57

Perceptual habits

Answer 57

ingrained patterns of organization and attention – perceiving things as they usually are e.g. laptop model (Microsoft vs Apple)

Question 57

Perceptual habits

Answer 57

ingrained patterns of organization and attention – perceiving things as they usually are e.g. laptop model (Microsoft vs Apple)

Question 58

Perceptual habits

Answer 58

ingrained patterns of organization and attention – perceiving things as they usually are e.g. laptop model (Microsoft vs Apple)