Lecture 6 - Sensation And Perception

Front 1

Sensation vs. perception

Back 1

Connects us to the physical world

Front 2

Sensation

Back 2

the stimulation of the sense organs; Absorption of energy (light, sound waves) by sensory organs such as eyes and ears

Front 3

Perception

Back 3

the selection, organization and interpretation of sensory input; Organizing and translating sensory input into something meaningful (ie. your best friends face, other environmental stimuli)

Front 4

Weber’s law

Back 4

states that the size of a JND is a constant proportion of the size of the initial stimulus (constant proportion=the “weber fraction”)

Front 5

Just Noticeable difference (JND)

Back 5

is the smallest difference in the amount of stimulation that a specific sense can detect

Front 6

Difference between Absolute Threshold and JND

Back 6

is at the JND; absolute threshold is the minimum amount of stimulation required for a person to detect the stimulus 50 percent of the time. The difference threshold is the smallest difference in stimulation that can be detected 50 percent of the time

Front 7

Just Noticeable difference (JND)

Back 7

is the smallest difference in the amount of stimulation that a specific sense can detect

Front 8

Absolute Threshold

Back 8

for a specific type of sensation input is the minimum amount of stimulation that an organism can detect; is defined as the intensity level at which the probability of detection is 50%

Front 9

Psychophysics

Back 9

the study of how physical stimuli are translated into psychological experience

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Vitreous humor

Back 10

a gelatinous fluid that maintains the ball-like shape of the eye

Front 11

Retina

Back 11

The neural tissue lining the inside back surface if the eye; it absorbs light, processes images, and sends visual information to the brain

Front 12

The Fovea

Back 12

a tiny spot in the centre of the retina that contains only cones; visual acuity is the greatest at this spot

Front 13

Cones

Back 13

specialized visual receptors that play a key role in daylight vision and colour vision

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Rods

Back 14

specialized visual receptors that play a key role in night vision and peripheral vision; Handles periphery as it outnumbers cones in the periphery of the retina

Front 15

Trichromatic theory of colour vision

Back 15

hold that the human eye has 3 types of receptors with differing sensitivities to different light wavelengths which work together to produce all the colours we see; red, green, and blue

Front 16

Colour blindness

Back 16

encompasses a variety of deficiencies in the ability to distinguish among colours

Front 17

dichromats

Back 17

they make due with only 2 colour channels (3 types of dichromats, each insensitive to red, green, or blue → most common)

Front 18

Complementary colours

Back 18

pairs of colours that produce grey tones when mixed together  Trichromatic theory doesn’t account for this

Front 19

Opponent Process theory of colour vision

Back 19

hold that colour perception depends on receptors that make antagonistic responses to 3 pairs of colours ie. Red vs. green, yellow vs. blue, black vs. white

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an after image

Back 20

a visual image that persists after a stimulus is removed)

Front 21

Dark Adaptation

Back 21

the process in which the eyes become more sensitive to light in low illumination, typically complete in 30 minutes; Cone adaptation

Front 22

McGurk Effect

Back 22

Multimodal integration; What you see and hear put together to perceive reality (gaga, baba, and dada)

Front 23

Synesthesia

Back 23

a condition in which perceptual or cognitive activities (listening to music, reading…) trigger exceptional experiences (ie. tasing a colour, seeing the colour red when you hear the world “train”)

Front 24

The ventral stream

Back 24

processes the details of WHAT objects are out there (form and colour perception

Front 25

Visual Agnosia

Back 25

an inability to recognize objects; Due to damage along the visual pathway that handles objects recognition

Front 26

Prosopagnosia

Back 26

an inability to recognize familiar faces (even one's own)

Front 27

Dorsal Stream

Back 27

which processes WHERE the objects are (motion and depth perception)

Front 28

Purkinje shift

Back 28

Enhanced sensitivity to short wavelengths during dark adaptation when the shift from cone to rod vision occurs  In the dark, the colour we see is a tinge of blue over everything

Front 29

Figure

Back 29

the thing being looked at; Appear closer and have more substance and shape and stand-out

Front 30

Ground

Back 30

the background against which it stands

Front 31

Proximity

Back 31

things that are close to are another and seems to belong together

Front 32

Closure/completeness

Back 32

people group elements in order to create this

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Similarity

Back 33

tend to group stimuli that are similar

Front 34

Simplicity

Back 34

people tend to group elements that combine to form a good figure also; Law of Pragnanz → “good form”

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Continuity

Back 35

tendency to follow in whatever direction they’ve been led

Front 36

Phi phenomenon

Back 36

the illusion of movement created by preventing visual stimuli in rapid succession

Front 37

Gestalt Psychology

Back 37

influential school of thought that repeatedly demonstrates that the whole can be greater than the sum of its parts Ie. movies and TV

Front 38

Binocular Depth cues

Back 38

clues about distance based on the differing views of the two eyes

Front 39

Retinal disparity

Back 39

refers to the fact that objects project images to slightly different locations on the right and left retinas, so the right and left eyes see slightly different views of the object = Closer the object, the greater the disparity

Front 40

Convergence

Back 40

involves sensing the eyes converging towards each other as they focus on closer objects

Front 41

Monocular depth cues

Back 41

clues about distance based on the image in either eye alone

Front 42

Motion parallax

Back 42

involves images of objects at different distances moving across the retina of different rates

Front 43

Pictorial depth cues

Back 43

clues about distance that can be given in a flat picture

Front 44

Linear perspective

Back 44

reflects the fact that lines converge in the distance

Front 45

Interposition

Back 45

the shapes of near objects overlap or mask those of more distant ones

Front 46

Relative size

Back 46

if separate objects are expected to be of the same size, larger ones are seen as closer

Front 47

Height in plane

Back 47

near objects are low in the visual field; more distant ones are higher up

Front 48

Light and shadow

Back 48

patterns of light and dark suggest shadows that can create an impression of 3D forms

Front 49

Ponzo’s illusion/Moon illusion

Back 49

the moon illusion-the fact that the moon is perceived to be about 50% larger when it is near the horizon then when seen overhead, despite the fact that they are the same size

Front 50

Linear perspective

Back 50

parallel lines appear to converge at some point in the distance; Our perception of distance affects our perception of length

Front 51

Stapes-oval window

Back 51

in the Inner ear; Sound enters through the oval window which is vibrated by the ossicles

Front 52

cochlea

Back 52

a fluid-filled tunnel that contains receptors for hearing; divided into upper and lower chambers

Front 53

Basilar membrane

Back 53

runs the length of the spiralled cochlea, and holds the auditory receptors called “hair cells” because of the tiny bundles of hairs that protrude with them  The hair cells convert this physical stimulation into neural impulses that are sent to the brain

Front 54

Corti

Back 54

inside the cochlea; It contains the hair cells, or cilia

Front 55

Gustatory receptors

Back 55

clusters of taste cells found in the taste buds that line the trenches around tiny bumps on the tongue; When these cells absorb chemicals dissolved in saliva, they trigger neural impulses that are routed through the thalamus to the cortex

Front 56

The Olfactory system

Back 56

the sensory system for smell

Front 57

Subliminal Threshold

Back 57

any sensory stimuli below an individual's threshold for conscious perception.

Front 58

Transduction

Back 58

the process that converts a sensory signal to an electrical signal to be processed in a specialized area in the brain

Front 59

Phosphenes

Back 59

a ring or spot of light produced by pressure on the eyeball or direct stimulation of the visual system other than by light

Front 60

Central Vision

Back 60

when the eyes are focused straight ahead, allowing us to drive, read, and see details sharply; only covers about three degrees of our visual field, but allows us to make very important judgments like estimating distance and understanding details in the path ahead

Front 61

Peripheral Vision

Back 61

Side vision. The ability to see objects and movement outside of the direct line of vision. Peripheral vision is the work of the rods

Front 62

Colour vision

Back 62

the ability of an organism or machine to distinguish objects based on the wavelengths (or frequencies) of the light they reflect, emit, or transmit

Front 63

Ganglion cells

Back 63

a type of neuron located near the inner surface of the retina that are the final output neurons of the vertebrate retina; collects visual information in their dendrites from bipolar cells and amacrine cells and transmit it to the brain through out their axon to the brain

Front 64

Autokinetic effect

Back 64

a phenomenon of visual perception in which a stationary, small point of light in an otherwise dark or featureless environment appears to move

Front 65

Blind-sight

Back 65

the ability of people who are cortically blind due to lesions in their striate cortex, also known as primary visual cortex or V1, to respond to visual stimuli that they do not consciously see

Front 66

Cross-modal sensory integration

Back 66

perception that involves interactions between two or more different sensory modalities. Ie Synesthesia and McGurk Effect

Front 67

Context and perception

Back 67

Context allowing us to perceive the same thing in different situations as different; Ie. a $10 coffee maker from Good Will as expensive and a $80 coffee make from starbucks as reasonable

Front 68

Motivation and perception

Back 68

Motivation allowing us to perceive a task as varying in difficulties; Ie. a practice exam to gain practice and a real exam to gain marks

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Pareidolia

Back 69

a psychological phenomenon involving a stimulus (an image or a sound) wherein the mind perceives a familiar pattern of something where none actually exists

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Apophenia

Back 70

the spontaneous perception of connections and meaningfulness of unrelated phenomena

Front 71

Subjective contours

Back 71

the perception of contours where none actually exist

Front 72

Interposition

Back 72

occurs in instances where one object overlaps the other, which causes us to perceive depth

Front 73

Perceptual constancy

Back 73

the tendency to perceive an object you are familiar with as having a constant shape, size, and brightness despite the stimuli changes that occur

Front 74

Illusions

Back 74

a thing that is or is likely to be wrongly perceived or interpreted by the senses

Front 75

Optical Illusions

Back 75

involves an apparently inexplicable discrepancy between the appearance of a visual stimulus and its physical reality

Front 76

Hallucination

Back 76

an experience involving the apparent perception of something not present

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Infrasound

Back 77

sound waves with frequencies below the lower limit of human audibility

Front 78

Ultrasound

Back 78

sound or other vibrations having an ultrasonic frequency (above audible frequency), particularly as used in medical imaging

Front 79

Epithelial cells

Back 79

cells that separate body cavities from the outside environment; different for the mouth, esophagus and part of the rectum