perception

Question 1

what is the differnece between sensation and perception

Answer 1

Sensation is the physical stimulation of sense receptors in the environment, whereas perception is the brain’s way of interpreting that info.

Question 2

how do sense receptors work

Answer 2

Sense receptors receive information and convert them into electrical impulses that then send that information to the brain to be processed.

Question 3

what is an example of a sense receptor

Answer 3

An example of sense receptors are the rods and cones found in human retina. They send messages to the brain which then connect directly to the brain.

Question 4

how does perception work

3 points

Answer 4

-many receptor cells needed to work together
-stimulus is moving around we can detect where it will be because of the changing light pattern hitting the retinal cells.
-works like a computer building a bigger picture that lets the person do actions

Many receptor cells are needed to work together for perception to occur. If a stimulus is moving around we can detect where it will be; we’d know this because of the changing pattern of light hitting the retinal cells. Our perceptual system also works as a computer- processing simple bits of information to build up to a bigger picture that then allows the individual to act.

Question 5

what are the 4 main types of perceptual constancy and explain what they are

Answer 5

-Light constancy: objects appear to retain the same physical properties like lightness/darkness despite the lighting.

-Color constancy: color appears the same despite certain lighting.

-Size constancy: when an object is the same size despite its distance changing

-Shape constancy: an image that has rotated is still perceived as the same object.

Question 6

what are monocular depth cues

Answer 6

Monocular depth cues are perceptual cues that can be detected with one eye

Question 7

what are binocular depth cues

Answer 7

Binocular depth cues are perceptual cues that can be detected with both eyes.

Question 8

what is retinal disparity

4

Answer 8

-2 diff images seen on each eye
-helps us understand depth and distance of an object
-occurs because eyes are 6cm apart
-tells us how close something is

Retinal disparity: the two different images our left and right eye see. it can help us understand the depth and distance of an object. This occurs because our eyes are 6cm apart, therefore we see different images on both eyes. Retinal disparity wrks because the closer an object the bigger the difference is between the two images.

Question 9

what is convergence

3

Answer 9

• how hard our eyes have to work
  to see 2 objects that converge
  -when object is close eyes converge but when item is far eyes r relaxed
  -helps us navigate depth+ distance

Convergence: this refers to how hard our eye muscles have to work to see two objects when they converge (get really close to one another).
Convergence works because when an object is close to us, our eye muscles have to work harder as our eyes converge but when an item is far our eye muscles are relaxed. This helps us navigate the depth and distance of objects in our environment.

Question 10

what are the 4 monocular visual cues

Answer 10

Height in plane: objects higher up in the image appear farther away. It acts as a depth cue.

Relative size: when objects appear smaller than other known objects of similar size in our visual field, they are perceived as farther away.

Occlusion: objects that are obscured by other objects that are far away.

Linear perspective: when parallel lines converge in the distance.

Question 11

Misinterpreted depth cues

Answer 11

we will sometimes perceive distance that isnt there and use the rule of size constancy when we dont need to.

Question 12

Ponzo illusion

2

Answer 12

Ponzo illusion:the horizontal line higher up in the image appears longer despite the fact that they are both the same size. The converging lines imply distance and our brain applies the rule of size constancy, mentally enlarging the top line to be longer than it is. the line at the top is perceived to be further away.

-higher line looks longer but theyre the same size
-converging lines imply distance and our brain apply size of constancy making it larger

Question 13

muller-lyer

4

Answer 13

Muller-lyer illusion: the vertical lines are the same in length yet the positioning of the arrow heads cause one of the lines to be perceived as longer as the fins are facing opposite ways. The theory behind this illusion is that we subconsciously perceive the line with outward facing fins as being the inner corner of a room-which we would consider to be stretching away from us- and the line with the inner facing arrowhead is perceived to be the outside corner of a building, which would be projecting out at us. We misinterpret the length to make it seem longer than it actually is.

-same length, one perceived longer
-theory is
- outward fins a corner of a room
stretching awayy from us

  - inward fins are like the outside of 
    a building that is projecting 
    outward

-we misinterpret the length making it seem longer than it is

Question 14

ames room

4

Answer 14

Ames room: the Ames room is an example of a misinterpreted depth cue. The room causes one person on one side to appear much bigger than the other. the room in actuality is trapezoid shaped with a back, roof, and side wall all sloping yet designed to appear like a normal shaped room. As people are used to box shaped rooms, we misinterpret the depth and believe one person to be much larger than the other.

-misinterpreted depth cue
- makes one person look bigger
-trapezoid with sloped architecture
-misinterpret depth cause of box shaped rooms

Question 15

ambiguity

Answer 15

ambiguous figures happen when there are multiple possible interpretations for the same image and the brain cannot decide which to focus on.

Question 16

The necker cube

Answer 16

The necker cube: the cube can be perceived as either facing the downward left or the upper right due to its ambiguous nature.

Question 17

Rubin’s vase:

Answer 17

in this illusion there are two interpretations: two faces staring at each other and a vase. Both interpretations are accurate so your brain cannot focus on one leading it to switch between the two perceptions.

Question 18

Fiction and Kanizsa triangle

Answer 18

Fiction: perceiving an image that isnt there. The stimuli may suggest there is one however there isnt.
Kanizsa triangle: this illusion shows us an image of a fictional triangle overlapping the first, even though there is nothing there. This works due to the placement of clean cut circles and lines causing us to see a fictional image.

Question 19

direct theory

5

Answer 19

Gibson believed that perceptual abilities are innate. Rich information that is available in the visual array of the environment around us is all that we need to perceive the world around us and gives us enough information about we need to judge depth, distance, and movement. Perception happens directly with sensation. He believed we do not need to fill in gaps by using past expectations or experience. that our eyes are sophisticated organs that have evolved to detect very small changes in our environment.

-innate

-information available in environmemt
was enough to perceive depth,distance movement

-perception happens directly with sensation

-we dont nee to fill in gaps with past experience or expectation

-eyes are sophisticated organs that have evolved to detect small changes in our environment

Question 20

optic flo pattern 3

Answer 20

the point we are moving towards stays stationary whilst the rest of our view rushes away from it. These optic flow patterns are directed by our eyes and let our brain know we are moving. This information lets our brain make judgements about the speed and direction of our movement. If there is no optic flow, there is no movement.

-stationary destination
-lets us know we are moving
-lets our brain know to make judgements about the speed and direction of movement

Question 21

motion parallax 3

Answer 21

Gibson believed that motion parallax was another type of monocular cue that helps us understand speed of movement. When we are moving, objects closer to us in our visual field will appear to move faster than objects further away from us.

-another type of monocular cue
-helps us understand speed of movement
-when we are moving close objects move fatser than far ones

Question 22

pro 1 gibson 5

Answer 22

he developed it with research on pilots in the real world; his theory was developed using ww2 pilot. He found that all the info a pilot needed to land an aircraft was in the total pattern of light that reached the eye, using details like the runway outline, the line of the horizon, the ground texture, and movemnt. His theory has real world relevance and does successfully explain how we perceive the world around us on a daily basis. Therefore this carries validity

-pilots
-all they need is the total patter of light that reached the eye, using details, like the runway outlike, the line of the horizon, the ground textures and movement
-real world relevance
-explains how we perceive the world
-carries validity

Question 23

con gibson

Answer 23

Con: it doesn’t explain illusion and perceptual errors. Visual illusions are designed to confuse the perception process and are good examples of how the brain can draw the wrong conclusion. His theory suggests we should be able to perceive things accurately using perception directly so this theory doesn’t explain why we make perceptual errors.

-doesnt explain illusion and perceptual errors
-brain can draw wrong conclusions
-we should perceive things accurately using perception
-doesnt explain why we make these errors

Question 24

pro 2 gibson

Answer 24

young infants provide support for this theory. Gibson set up an experiment in which 6 month old babies were places on a cliff like edge( that was covered with perspex) and were encouraged to crawl across it to their mothers. Very few did. Gibson argues that this showed the innate feature of perception as the babies showed clear awareness of depth but were too young to have learnt perception, reinforcing his theory.

6 month old kids
cliff like edge encoursged to crawl cross
few did
shows innate feture of perception as theyre too young to have learnt any concpets

Question 25

Gregory’s theory on constructivist perception

Answer 25

we percept things by building our perceptions party on incoming data and partly on clues from what we know about the word; we use past experience to guide our perception. This theory is known as top down processing. It begins with thoughts and memories rather than physical sensation.

-incoming data
-clues
past experiences
-top down processing begins with thoughts and memories instead of physical sensations

Question 26

what does gregory’s theory say about how we perceive the world

Answer 26

Gregory believed we make assumptions about items/events and construct the world around us.

Our brain will fill in the gps of our sensory experience, using our past experience to draw a conclusion on what we see.

Question 27

how does gregory’s theory explain illusions

Answer 27

depth color and height of an item will be used to interpret what we see.

This usually helps us then make a good judgement about what it is we are seeing.

However this can be wrong at times- Gregory calls this a mistaken hypothesis because the brain has drawn the wrong conclusion from available evidence.

Question 28

state a difference between gibson and gregory

Answer 28

Unlike Gibson, Gregory believes that our understanding of visual cues is learned from experience due to nurture.

As we grow and interact with things our perception will become more sophisticated.

Question 29

pro 1 greg

Answer 29

Pro: one strength of this theory is that research supports it y showing cultural differences in perception. In 1960 Hudson found that culture seems to affect how people perceive visual images. Native black south Africans struggled to interpret a 2-d picture using depth cues, whereas european participant could use depth cues to interpret the picture. This shows what you learn is an important part of what you see. Gregory’s theory explains this better than Gibson’s theory which doesn’t account for cultural differences.

Question 30

con 1 greg

Answer 30

Con: one weakness of Gregory’s theory is that it doesn’t explain how perception starts out.there are lots of evidence that show babies have some perceptual abilities from birth. It has been shown that babies prefer human shaped faces over random patterns. This shows that babies do in fact have natural ability to percept things as they are too young to have experience or learn this ability.

Question 31

pro 2 greg

Answer 31

the hollow-face shape illusion supports this theory. The people see the image of the hollow mask’s back they perceive it as being a 3d face. This occurs because of our exoerience and expectation. We are used to seeing 3d faces and therefore misinterpret the hollow mask as an outward pointing face. this demonstrates the role of expectations and nurture, supporting the constructivist’s theory.