lecture 4 Flashcards

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1
Q

What is the process from sensation to perception

A

stimulus energy, sensory receptors, neural impulses, brain (perception)

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2
Q

can Perception change

A

Perception is subjective and can change

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3
Q

what does Pain perception depend on

A

Pain perception changes depending on what is expected

Pain ratings for the electrical shock were higher in the high-cue (high pain expectancy) trials than the low-cue (low pain expectancy) trials despite the shock being at the same level

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4
Q

what is Synaesthesia

A

Stimulation of one sense simultaneously produces another sensation in a different modality (senses can mix)

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5
Q

what is Grapheme-color synesthesia

A

¤ Seeing certain numbers or letters as certain colors (red twos and green 5’s)
¤ May be learned (studies show that it may be because we learn the alphabet with colours

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6
Q

what is our dominant sense/percept

A

Vision

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7
Q

what is the McGurk Effect

A

¤ Speech sound /ba/ simultaneously presented with visual speech sound /fa/ heard as /fa/

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8
Q

what is A multisensory illusion

A

change in auditory perception from visual input

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9
Q

is the mcgurk effect a A multisensory illusion

A

yes

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10
Q

what does the mcgurk effect demonstrate

A

¤ The integration of sensory information ¤ The power of visual input
¤ It over-rides audio input!

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11
Q

When we see, is there input into the eye or output from the eye

A

input into the eye

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12
Q

what is the Extramission belief

A

When we see, there is a ray that exits the eye onto an object (an output; false)

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13
Q

what is the experiment that proved that most people believe that the extramission is correct

A

Ask participants: How does vision work?
Tested three ways: 1.Computer graphics 2. Verbal descriptions 3. Verbal Reports
Results: The majority favoured a view of vision that had some variant of extramission belief that was found for all ways of testing

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14
Q

when people had education nohow vision worked, do they still believe in extramission

A

yep, not all but a good chunk of them

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15
Q

what is the difference between early and late visual processing

A
¤ Early visual processing 
     ¤ Sensation
     ¤ Eyes and the optic nerve
¤ Late visual processing      
     ¤ Perception
     ¤ Visual cortex (Occipital lobe)
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16
Q

what are the 4 steps of Early visual processing

A
  1. Light waves enter the eye, focused onto the retina
  2. Photoreceptors in the retina convert light to electrical activity
  3. The electrical signal is sent to bipolar cells and then to the ganglion cells
  4. The electrical signal is sent to bipolar cells and then to the ganglion cells
    4
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17
Q

what is the retina

A

A thin layer of tissue at the back of the eye

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18
Q

what are the different photoreceptors

A
  1. Light waves enter the eye, focused onto the retina
    ¤ A thin layer of tissue at the back of the eye
  2. Photoreceptors in the retina convert light to electrical activity
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19
Q

are there the same number of photoreceptors as ganglion cells and other cells in vision

A

NO

Millions of photoreceptors in each retina converge onto 100 x fewer ganglion cells à optic nerve à brain

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20
Q

Millions of photoreceptors in each retina converge onto 100 x fewer ganglion cells à optic nerve à brain
what does this mean

A

the message from the eyes to the brain is compressed

You don’t ‘see’ everything that is out there in the world

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21
Q

where are Photoreceptors located

A

back of the retina (farther from the ‘world’)

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22
Q

where are Ganglion cells located

A

are at the front of the retina (closer to the ‘world’)

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23
Q

Cones (high light level photoreceptors) are mostly where

A

in the fovea

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24
Q

what is the fovea

A

¤ A small area on the the central part of the visual field

¤ Most of our detailed vision in the center of our visual field

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25
Q

where are Rods

A

mostly outside of the fovea, in the periphery

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26
Q

what are the characteristics of periphery

A

Peripheral vision is less detailed and better for seeing at night

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27
Q

what is perceptual filling in

A

peripheral vision not as detailed as the centre but we don’t realize because the eye/brain fills in the image around it with details and it looks fine for us

28
Q

what do the ganglion cells make up

A

Ganglion cells make up the optic nerve that take this signal to the brain

29
Q

what is the optic nerve

A

¤ Ganglion cells make up the optic nerve that take this signal to the brain
¤ Has to move past the photoreceptor layer, so at this ‘exit location’, there are no photoreceptors
¤ This means there is no way to pick up visual stimuli (light signals) at this point (there is a blindspot here)

30
Q

why do we not see our blindspot

A

¤The left and right eyes compensate for blindspots ¤Perceptual filling-in

31
Q

what is Perceptual filling-in

A

Later visual processes in the brain provide the missing information by ‘interpolating’ visual information (e.g., colors) from surrounding areas

32
Q

how does Early to late visual processing work

A

Happens via the optic nerve

33
Q

Each eye’s optic nerve transmits

information to where

A

both hemispheres

34
Q

what half of the brain sees the left visual field

A

Left visual field is perceived via the

right hemisphere

35
Q

what half o the brain sees the right visual field

A

Right visual field is perceived via left hemisphere

36
Q

what is Contralaterality

A

information from the world is transmitted to opposite halves of the brain

37
Q

what are Visual Association Areas

A

Interprets and understands visual information; assigns meaning to what we see

38
Q

what are the Different streams in the visual association areas

A

ventral

dorsal

39
Q

what is the ventral stream

A

¤ What (ventral) pathway

¤ Occipital to temporal lobes ¤ Shape, size, visual details

40
Q

what is the dorsal stream

A

¤ Where (dorsal) pathway

¤ Occipital to parietal lobes ¤ Location, space, movement

41
Q

what do neural imaging studies show us about the dorsal and ventral pathways

A

Neuroimaging studies: object identification vs spatial location tasks activate the what vs where pathways

42
Q

do the dorsal and ventral streams integrate

A

yep– they communicate

43
Q

do we sense or perceive information directly

A

We don’t sense or perceive information directly

44
Q

do we receive ALL visual stimuli

A

no
Visual stimuli is altered/‘broken apart’ in the processing pipeline

¤ Compression
¤ Functional specialization in the primary visual cortex

45
Q

what is meant by “Perceiving = Constructing”

A

pieces of information are integrated back together to be interpreted as a whole (from vision)

46
Q

what is implicit perception

A

Perception without ‘consciousness’ or awareness that still affects behaviour

47
Q

how to Measure implicit perception

A

¤ Blindsight individuals
¤ Laboratory measures
¤ Subliminal priming & backward masking

48
Q

what is blindsight

A

¤ Damage to the primary visual cortex
¤ Patients report no awareness of stimuli in their damaged visual field
¤ They can correctly respond to questions about objects presented in the damaged visual field area if given a forced-choice task
¤ They perceive something without knowing it

49
Q

whats the experiment used for people with blindsight

A

Test:Turn a light on or off inthe blinded visual field over a series of trials


Asked the patient to guess if the light is on or off (forced-choice task)
Result: Patients with blindsight perform above chance for forced choice responding about the presence of light in the blinded area

50
Q

is there much activity is the brain of blight sight people when perceiving faces and houses

A

¤ Activity of patient with blindsight perceiving faces and houses
¤ Much less than in controls

51
Q

is there much activity is the brain of blight sight people when IMAGINING faces and horses

A

¤ Activity of patient with blindsight
when imagining faces and houses
¤ More extensive and similar to controls

52
Q

what do the findings about the imagery activity in the brain vs perception activity in the brain of blindsight people mean/lead to

A

idea that There may be other pathways for visual information to bypass the primary visual cortex to be processes

53
Q

There may be other pathways for visual information to bypass the primary visual cortex to be processes
¤ but These cases rely on what

A

people reporting their state of awareness ¤ Accepts that people have access to this information

54
Q

Some individuals with blindsight report a non-visual feeling that something happened– explain

A

“[it’s like] waving your hand in front of your eyes when they are closed. You are kind of aware that something happened but you don’t quite see it.”

55
Q

how to test Implicit perception

A

Subliminal priming

56
Q

what is Subliminal priming

A

Test the effect of stimuli presented without conscious awareness (below threshold of awareness – limen) on a measured behavioral outcome
¤ A change in behaviour indicates priming

57
Q

what is Backward masking

A

¤Method to present stimuli without awareness 1.Briefly presenting a stimulus (target)
2. Mask that target with a second stimuli
¤ The mask reduces the visibility of the target
¤ Target information is unavailable to conscious report ¤ The target can still influence processing
3.Measure the effect of target information on subsequent tasks: priming experiments

58
Q

what was the experiment done with backward masking

A

Measured the reaction time to name the color patch
o Faster naming when the masked target was congruent with the color patch than incongruent (not same colour as word) with the color patch
o Target was processed even when presented below awareness

59
Q

can Perception occur without awareness

A

Perception can occur without awareness

60
Q

what are Blindsight patients

A

¤Unable to consciously see visual information from the affected visual field but can still respond to it on forced- choice tasks

61
Q

what are Priming experiments

A

Information presented to participants that they are not aware of still affects behavioral performance

62
Q

Change blindness shows that …

A

¤Not all of our perceptual environment reaches our awareness
¤There is an interaction between attention and perception
processes
¤Our visual experience is underdetermined by (i.e., less than) what is input to the visual system

63
Q

how is Perception is an illusion!

A

¤ Information is lost as it is processed in the visual system ¤ We use shortcuts/assumptions to perceive
¤ This is what makes us susceptible to visual illusions
¤ The illusions we are susceptible to illustrate our heuristics

64
Q

what are heuristics

A

assumptions about regularities in the world that we bring to perception

65
Q

¤ We don’t perceive everything in our environment ¤ E.g., change blindness experiment
¤ This is because why

A

perception is an active and constructive process ¤ We used quick and dirty estimate of the world
¤ This leads to misinterpretations of the world: Visual illusions

66
Q
Which cells located in the retina are concentrated in the fovea? A.) Ganglion cells
B.) Optic Nerve
C.) Rods
D.) Cones
E.) Both Rods and Cones
A

D.) Cones