Perception Flashcards
What is sensation?
The physical process of collecting data from the environment using the senses
What is perception?
The cognitive process of interpreting or making sense of sensory information that we receive. Experience builds and shapes our perception
What are monocular depth cues?
Cues that tell us approximately how far away something is using one eye
What are some examples of monocular depth cues?
Height in plane - objects higher up appear further away
Relative size - the more distant an object is, the smaller the image of that object appears on your retina
Occlusion - objects which obscure others appear closer
Linear perspective - parallel lines that go back into the distance appear to get closer or join
Motion parallax - when you are moving, stationary objects closer to you appear to move faster
What are binocular depth cues?
Cues that tell us precisely how far away something is using both eyes
What are the two types of binocular depth cues?
Retinal disparity - the difference between two images when something is closer to you (left and right fields of vision provide slightly different visual images when focusing on a single object)
Convergence - the muscles in our eyes working harder when looking at something close to us
What is size constancy?
We keep our original perception of the size of an object, even when information received by the eye changes, such as seeing people appear smaller when they are far away yet knowing they are the same size.
What are visual illusions?
When our visual perception is tricked into seeing something inaccurate as the brain uses inappropriate strategies to interpret the sensory info it receives
What is a misinterpreted depth cue?
Our brain making out distance when it isn’t there, applying the rule of constancy when it isn’t there. An example is the Muller-Lyer illusion where one line appears longer even though they are the same length
What is an ambiguous visual illusion?
When there are different interpretations of the same image, the brain cannot decide which interpretation to choose so it will flip between them. An example is the Rubin’s vase illusion where you can see both two faces and a vase
What is a fictional visual illusion?
Where you start to see something in the image that isn’t actually there due to the image suggesting a certain aspect is present when it isn’t. An example is the Kanizsa triangle where it is suggested a second triangle is present when it isn’t
What is Gibson’s direct theory of perception?
Gibson stated that sensation and perception are essentially the same thing. He stated that everything in our visual field and what our eyes perceive is everything we need to judge depth, distance and movement without past experiences
What are the 3 main parts of his theory?
Optic flow patterns - when we are moving towards a fixed point it stays stationary while the rest of our view appears to rush by. If we do not see this optic flow, it struggles to recognise we are moving
Motion parallax - objects appearing to move faster when closer
Influence of nature - perception is innate. The eye can detect changes in light, texture, movement and depth without past experiences
Evaluations of Gibson’s direct theory? (NATURE)
Strength - supporting research - visual cliff experiment shows that we do not need to learn how to perceive the world around us as babies do not crawl off the edge. Strength because it supports the theory and shows we do not always need past experiences to perceive the world around us
Weakness - perceptual errors are not easily explained by Gibson’s theory. Visual illusions are good examples of when our brain makes perceptual errors, however Gibson said there is no need for processing info we receive, yet illusions show sensation and perception to be different
What is Gregory’s constructivist theory? (NURTURE)
Gregory stated that we perceive based on past experiences. We make sense of the world around us by building perception based on incoming information and what we already know about the world
What are the parts of Gregory’s theory?
Interference - a lot of what we perceive in the world is incomplete and ambiguous, meaning our brain will fill in gaps using interference, which is our brain using info available to guess what we are seeing
Visual cues - the brain receives help when making interferences in the form of visual cues. Our perception is inaccurate when we interpret things wrong in an illusion
Evaluations of Gregory’s theory
Strength - supporting research - Seagall et al found people in non-western cultures don’t fall for the Muller-Lyer illusion, meaning our perception must be influenced by our experience otherwise everyone would fall for the illusion
Weakness - contradicting research - visual cliff experiment
What factors affect perception?
-Culture
-Emotion
-Motivation
-Expectation
Hudson’s study (effect of culture on perception) AMRC
A - to see if people from different cultures interpret information differently using depth cues
M - Showed 2D images to people from different cultures and educational backgrounds of a man hunting an elephant/antelope
R - Educated ppts more likely to perceive depth than uneducated ppts. White ppts more likely to perceive depth than black students
C - Culture seems to play a role in our perception
Hudson’s study evaluations
Weakness - the task required a translator and so the ppts may not have fully understood the task, meaning instructions may have been unclear and so instructions may have been received differently
Gilchrest and Nesberg (motivation effect on perception) AMRC
A - to see if food deprivation would make food appear brighter
M - two groups of people, 26 ppts without food for a day and ppts with food. They were shown slides of a meal for 15 seconds and asked to adjust lighting on a new photo until it looked like the previous one
R - Food-deprived ppts adjusted the lighting so it was brighter than original, whereas other ppts adjusted it to normal
C - Hunger is a motivating factor that affects perception. Being deprived of basic needs makes us sensitive to food related pictures
Gilchrest and Nesberg evaluations
Strength - validity - similar studies found similar results, such as vague objects appearing to be food when viewed by food deprived ppts
Weakness - ethics - depriving people of food may have caused discomfort and they may have felt pressured into remaining in the study, causing ethical concerns
Bruner and Minturn (Effect on expectation on perception) AMRC
A - to see whether expectation is an important factor in perception
M - showed ppts an ambiguous figure (that looks like a B or the number 13) with the first group of ppts shown the figure between A and C, the second group shown it between 12 and 14.
R - the group who saw it between 12 and 14 saw it as 13 but the group who saw it between A and C saw it as a B
C - expectation is an important influence on perception
Bruner and Minturn evaluations
Strength - real-life application - War of Ghosts study explains why ppts changed the story based on their expectations. Strength because we have evidence to support the credibility of the theory
Weakness - two groups of ppts - due to individual differences, such as having 13 as your favourite number, there may have been other factors affecting perception, meaning expectation may not have been the key factor
