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Flashcards in Sensation And Perception Deck (118):
1

What is information?

Anything that reduces uncertainty

2

What is sensation?

Awareness resulting from stimulation of sense organ

3

What is perception?

The organisation and interpretation of sensations

4

Psychophysicists

Psychologists that explore changes in physics state corresponding to changes in mental state

5

Absolute threshold

The intensity of a stimulus that allows an organism to just barely detect it 50% of the time

6

Weber fechner law relies on the idea that we all have different threshold to the exact same stimulus at different times. What is the law?

Just noticeable different (JND) is NOT fixed. It is a constant proportion of the baseline against which the comparison is being made

7

Weber fraction

Delta l divided by l = k

8

Signal detection theory

Differentiates between two independent components that make up a person performance

1. Sensory sensitivity (precision)
2. Cognitive response (bias)

9

What limits sensory sensitivity?

Quality of organs

10

What influences someone’s decisions?

Confidence, motivation, desire to not miss a stimulus, desire to avoid incorrectly detecting a stimulus

11

What is signal detection theory helpful for?

It helps distinguish between a person sensitive and bias by combing their hit rate with their false alarm rate

12

Electrochemical activity

How the neutrons interact with environment

13

Senses detect:

Useful information through physical energy from the environment and convert into electrochemical activity

14

Sensory transduction

Conversation of physical energy into neural energy

15

Sensory receptors are:

Class of cells that perform sensory transduction

16

What are the three sensory receptors?

SES

Simple

Encapsulated

Specialised

17

Simple receptors describe and function

Free nerve endings

Dendrites exposes to raw environment - touch, pain and pressure

18

What are Unspecialised cell types

Different environmental stimuli can elicit them / making them imprecise

19

Encapsulated receptors

Neuron with specialised dendrites

More specialised than free nerve endings ie responds to rapid vibrations

20

Specialised receptors

Dendrites have been modified making them highly responsive to a specialised environmental stimulation

21

Specialised senses are:

Vision

Hearing

Smell

Taste

Balance

Touch and pain

22

Why did specialised senses develop?

Due to evolutionary past which needed to excel in a particular domain

23

Light

Photons of electromagnetic energy that oscillate with a particular wavelength

24

Wave length of light

Determine perceived colour

25

Amplitude of light

Determines its perceived intensity

26

What do photoreceptors consist of?

Rods and cones

27

What are the three cones and what are they sensitive to?

Where are they located and what do they do?

Red, green and blue

Sensitive to particular wave lengths

Densely packed in retina providing high resolution neural responses to a visual image

28

What do rods do? Where are they located?

More sensitive to light

Precedent in retina

Useful for at night

29

Explain the process of vision

Light refracted by cornea, enters pupil, refracted by lens to cast clear image in retina at the back of the eye

30

Accomodation is

Lens adjusting thickness to refractive power

31

What is more powerful lens or cornea? And what makes it more powerful?

Cornea more optically powerful than lens. Refracts incoming light to a far greater extent

32

Where are rod and cones located?

Deepest layer of retina

33

What are retinal ganglion cells and where are they located?

Axons of ganglion cells in retina carry visual information from each eye to brain by optic nerve

Located: upper most layer of retina

34

Optic nerve

Bundled axons of ganglion cells

35

What is the blind spot?

Area where the axons of the retinal ganglion cells leave the eye in the periphery of the eye

36

What do visual cortex neurons respond to? And what are they often refered to as as a result?

Patterns of light and dark, direction of motion
Signal presence
Basic visual feature
Orientation
Width
Direction of motion

Detector neurons

37

Myopia

Only see objects close

Cornea/lens too strong or eyeball is too large

38

Hyperopia

Able to see object far

Cornea/lens too weak or eyeball is too small

39

Presbyopia

Lens unable to increase in thickness thus person can’t see nearby object as it moves closer

40

What fraction of people are deficient in their red or green cone?

1/50

41

What is ishihara?

Most widely used colour vision test

42

Key forms of visual
Information?

Colour

Form

Depth

Motion

43

How many colours can the 3 cones code for?

16 million

44

Trichromacy theory

The colour we perceive a colour to be depends on the relative activity of our three types of cones

45

Opponent process theory:

The colour we perceive depends on the relative activity of three pairings of colour sensitive neurons, in which the activity of one member of each pair inhibits activity of the other member of that pair

46

How do we perceive visual shapes?

By organising basic visual feature information by neuron of the visual cortex

47

Gestalt principles help the process of organising basic visual features of information provided by neurons of the visual cortex, what are they?

Group features into:
Figure vs ground object perception

Similar in shape
Close in coherent objects
In a way that favour continuity

48

What do Monocular depth cues do and what are they?

Guide the way in which visual information is perceived 3D if we are using one eye

Pictorial

Physiological

Motion

49

Pictorial cues

Relative

Position/height
Relative size
Linear perspective
Light and shadow
Interposition/occlusion
Aerial perspective

50

Physiological cues to depth

Accomodation

51

Explain binocular cues

When objects are close or further away from fixation point the two images start to diverge or converge. Specialised neuron invisual cortex compares inputs from each eye and Devine depth detectors

52

What do motion detectors do?

Responds to any shape size, shape or pattern only when it is moving in a particular direction and at a particular speed

53

Beta effect

Series of still images in quick succession with location change slight rah time - create illusion of fluid movement

54

Phi phenomenon

Two seperate images flicker on and off in alternation perceiving the illusion of motion between two images

55

What is persistence of vision?

Activation of the motor neurons in the cortex

56

What is sound?

Vibrational energy in the form of pressure wave emanating from
Some vibrating source

57

How are pressure waves carried?

Air molecules

58

What is amplitude of sound, how it is measured and how is it perceived?

Corresponds with intensity of sound and is measured in decibels and perceived as loudness

59

What is frequency of sound? How is it measured? How is it perceived?

Perceived tone or pitch and measured as hertz - cycles per second

60

What are mechanoreceptors

Each mechanoreceptor is a cilia that transducers vibrational energy into neural activity

61

Basilar membrane

Cilia sit

62

Tectorial membrane

Cilia embedded

63

How is sound carried?

Enter pinnae in ear canal causing tympanic membrane to vibrate which. Malleus, incus, stakes oscillated and amplified the sound. Stairs creates push pull on oval window of cochlea which causes vibrational energy to pass down basilar and tectorial membrane jerking back and forth results in electrochemical impulses from hair cell.

64

How are. Shrine of auditory cortex arranges?

Tonitpically

65

What does tonitopically
Mean?

Neurons of auditory cortex arranges like a keyboard with sensitivity to higher pitch move along surface of cortex towards back of brain

66

What causes conductive hearing loss?

Inability for tympanic membrane to vibrate sufficiently or ina import for ossicles to transmit vibrations to cochlea

67

What is sensorineural hearing loss?

Damage to cilia from prolonged loud noise

68

Tinnitus

Bussing or ringing from damaged cilia

69

How does a cochlear implant work?

Strip of electrode bypasses damaged cilia. Electrode implanted alongside basilar membrane and directly stimulates cochlear nerve cells

70

What is binaural perceptual ability

Inputs fromcochlear nerve combine inputs from two ears. Beauties receive stimulation from both ears and allow us to compare sounds from two ears. 2D to 3D

71

What does vibrational frequency correspond to?

Perceived pitch

72

What is frequency theory?

Frequency of oscillation of the basilar membrane will produce the same frequency of the basilar membrane

73

What is the maximum frequency one cilia can detect

100Hz

74

What is the volley principle?

Between 100-400Hz results in ensembles of cilia firing in response to vibrations sound energy and collectively code the frequency of the sounds

75

What is place theory?

Base of basilar
Membrane closest to ova
Window is stiffer than apex which is looser thus vibrates more

76

Location of cilia on basilar membrane can code for up to what frequency?

20000 Hz

77

What is detecting pure tones important?

Pure tones together produce complex vocalisation type sounds - speech sounds

78

What is taste?

Chemicals dissolved in saliva

79

What is smell

Airborne molecules

80

What do chemoreceptors that makeup taste buds on the tongue do?

Transducer presence of chemicals dissolved into neural impulses

81

What do chemoreceptors in each of the olfactory bulbs of the brain do?

Transducer presence of chemical in the air we inhale into neural
Impulses

82

Why is lock and key insufficient to intimating electrochemical impulses?

Chemoreceptors in mouth and nose produce short lived response

Chemicals often get stuck in receptor site thus new chemicals cannot bind to site

83

Taste bud and epithelial cells

Fastest growing cells in the body

Often absorbed back in the body and recycled

84

Taste bud

Each bud is made up seperate receptor cells and supporting cells

85

Taste pore

Exposed receptors of embedded taste bud and this is where sensory transduction occurs

86

Sensory transduction

Receptors exposes to dissolved chemicals
In saliva turn into neural
Impulses

87

Olfactory receptor cells

Extension of olfactory nerves into the olfactory membrane of each bulb

88

What are at the end of each olfactory receptor cell?

Tendrils

89

What do the tendrils do

They process receptor sites which airborne molecules bind and trigger neural impulses in tonthe receptor sites

90

Gustatory cortex

Cortical region devoted to processing taste information

91

Olfactory cortex

Cortical region devoted to processing odour information

92

Both gustatory and olfactory are between temprable and frontal lobes what else does this connect them with?

Spatial information, spatial memories, things that are relevant to generating emotional responses to stimuli and emotions

93

Why is it important that smells and taste are linked to memory?

Protect us from bad food
Fitness potential of mate
Infant

94

Proximal stimulus

Chemical stimulus makes direct contact ie food in taste bud

95

Distal stimulus

Location of chemical
Uncertain ie smell is airborne

96

Types of energy sources

Mechanical
Thermal
Chemical

97

Mechanoreceptors in skin do:

Transducer pressure, vibration, stretch, texture

98

Proprioceptors

Location: muscles, tendons, joints

Function: respond to position, movement and strain

99

Most important proprioceptors

Muscle spindle organ

Golgi tendon

100

Muscle spindle organ

Sits in normal muscle and responds to change in length of
Muscle

101

Golgi tendon organ

Sit in tendon and responds to stretch and strain in tendon

102

Function of mechanoreceptors in vestibular system

Detect rushing of fluid in canals due to movement of head

103

Nocioreceptors

Free nerve endings in skin and throughout the body

104

Which receptors does the spinal cord receive inputs from and where does it convey it?

Proprioceptors and mechanoreceptors send inputs to spinal cord and then conveys it to somatosensory cortex

105

Reflex

Information from thermoreceptors go straight to spinal cord and not the brain

106

Gate control theory of pain

Neuronal signs for pain compete along the way to the brain with touch, pressure and vibration. Thus why we put pressure on something when it’s painful

107

Nocebo

Experience of pain due to anticipation/expectation of administering painful stimulus

108

Sensory process

Detect potentially useful info to form patterns of physical energy

109

Perceptual processes

Organise information into coherent object precepts and then integrate this information with cognitive information

110

Key feature of perception

Bottom up - occur automatically without cognitive effort (perceptual reflexes)

111

Key features of perception

Requires integration with cognitive systems in order to achieve object understanding

112

Visual agnosia

Perceptual problems - difficulty in organising objects that is greater than visual deficiency ie difficulty with object that are cluttered, shadowed etc

113

Associative agnosia

Deficiency in the integration of perceptual information with cognitive information ie can discern between shapes, patterns and colour but can’t identify function of objects

114

Prosopagnosia

Inability to recognise faces

115

Integrative agnosia

Combination of associative and integrative agnosia

116

Auditory agnosia

Can’t understand/recognise common sounds

117

Tactile agnosia

Difficulty in recognising objects by touch

118

Anosognoaia

Deficits in perceiving damage or illness in ones own body