perception Flashcards
perception
how we interpret or make sense of the sensory information that we receive
sensation
the information that we receive through our sense
binocular depth cue
a way of detecting depth or distance, which requires two eyes in order to work
depth cue
a feature of an image which indicates distance
convergence
a form of depth perception which uses how eye muscles focus on an image
convergence explanation
Convergence works by detecting differences in our eye muscles. Our eyes focus differently when we see things that are closer compared to how they focus when things are further away. The brain detects the differences in how these muscles are working and use this as a cue to perceive distance.
retinal disparity
a form of depth perception which compares the images from two eyes side by side
retinal disparity explanation
Retinal disparity. The difference between the sensory information received through each eye which is the result of the slightly different angles they have of the world. The more disparity the closer an image/object is.
monocular depth cue
a way of detecting depth or distance, which will work with just one eye
the monocular depth cues examples
occlusion, linear perspective, height in plane, relative size
height in plane
how high the object appears in the image
linear perspective
when straight lines are angled so that they would come together at a point on the horizon
relative size
how large an object appears in an image
occlusion
when one object seems to cover part of another object
visual illusion
a visual perception which is wrong or misinterprets what is actually there in reality
reasons our brain is tricked by illusions
misinterpreted depth cues, ambiguity, fiction, size constancy
ambiguity
having more than one possible meaning or interpretation
fiction
the perception of an object or movement that is not present in the stimulus
size constancy
keeping our original perception of the size of an object, even when the information received by the eyes changes
misinterpreted depth cues
when a depth cue is used inappropriately
visual illusions examples
the necker cube, the ponzo illusion, the müller-lyer illusion, the ames room, rubin’s vase, the kanizsa triangle
examples of misinterpreted depth cues
ponzo illusion (linear perspective), müller lyer illusion (relative size)
examples of ambiguity
rubin’s vase (two people or a vase), the necker cube (flips between different versions)
examples of fiction
the kanisza triangle (shapes around it suggest a triangle)
examples of size constancy
ames room (our brain used to rooms being square)
gibson’s direct theory of perception
stated that sensation and perception are the same. we don’t need past experiences to judge depth distance and movement, only what is already in our visual field.
- optic flow pattern, when moving towards a fixed point it stays stationary while everything else rushes past us
- motion parallax, the way that the visual field changes with movement, with close objects seeming to move more quickly than objects that are further away
- influence of nature, we don’t need to learn how to perceive, our abilities are innate.
motion parallax
the way that the visual field changes with movement, with close objects seeming to move more quickly than objects that are further away
inference
a conclusion reached on the basis of past experience or knowledge
nature
the idea that our characteristics and behaviour are inherited
visual cliff experiment
evidence from experiments on infants which show that they are able to perceive depth. in the experiment the fact that babies of 6-12 months old were able to perceive depth is evidence that we are born with this ability and supports gibson’s theory
evaluation of gibson’s
+ visual cliff experiment
+ theory has real world meaning,research was based on pilots in WW2
- struggles to explain visual illusions, theory states that we always perceive accurately but illusions involve misperception
- there are studies that demonstrate that our expectations affect our perception
gregory’s constructivist theory of perception
proposed that we perceive based on our past experiences. we make sense of the world around us by building our perceptions based partly on incoming information and what we know about the world.
- inference
evaluation of gregory’s
+ research supporting it. e.g a study done showed that people in non-western cultures don’t fall for the muller-lyer illusion
- research that contradicts it, the visual cliff experiment
constructivist theory
the idea that our perception is built up from our prior knowledge and experience
nurture
the idea that our characteristics and behaviour are influenced by our environment
factors influencing perception
- culture
- emotion
- motivation
- expectation
culture
a group of people who share similar customs, beliefs and behaviour
expectation
the beliefs we have about what we are going to experience
innate
inborn or inherited, not learned
perceptual set
a state of readiness to perceive certain kinds of stimuli rather than others
motivation
the drives and needs that cause a person to act in a particular way
emotion
the moods or feelings that a person experiences
gilchrist and nesberg’s need and perceptual change study aim and study design
to investigate how motivation affects perception.
laboratory experiment
gilchrist and nesberg’s method
26 uni students volunteered to go 20 hours without any food, and to only drink water. they were randomly allocated to be in one of two groups: one which actually went 20 hours without food, and the other, a control group, which had their normal meals during the 20 hours.
they were shown 4 slides of a meal for 15 seconds each. after each slide was shown, each picture would be shown again but this time dimmer. the participants had to turn a knob to adjust the brightness of the picture to match the original
they were tested at the beginning of the study, after 6 hours, and after 20 hours
gilchrist and nesberg’s results
the control group showed little difference in their memory of the brightness of the picture as time went on. but as the experimental group became hungrier, they judged the pictures to be brighter.
gilchrist and nesberg’s conclusion
hunger can affect the way that we perceive images of food, which suggests that motivation affects perception
gilchrist and nesberg’s evaluation
+ standard procedure, easy to replicate
+ ecological validity as the experiment involves hunger
+ similar studies with the same results
- ethical issues of depriving them of food
- cannot generalize results, very few participants all students of similar age
bruner and minturn’s perceptual set study aim and study design
to investigate how expectations can direct perception
laboratory experiment
bruner and minturn’s method
24 student participants were asked to take part in an experiment on recognising numbers and letters. they were split into two groups using independent measures design.
The test stimulus was a broken ‘B’, meaning it could be seen as either a B or the number 13. this was shown to participants after they were flashed a series of either letters, numbers, or a mix very quickly.
The first group was shown the series in the order of letters first, then numbers, then a mix (they were shown the test stimulus after each series). The second group was shown the series in the order of numbers first, then letters, then a mix.
bruner and minturn’s results
most participants drew the number 13 when they were expecting a number to come up, and the letter B when they were expecting a letter to come up. When they were expecting either a letter or a number they produced mixed results
bruner and minturn’s conclusion
the researchers concluded that the participants’ expectations had directly affected how they interpreted the stimulus figure.
evaluation of bruner and minturn’s
+ standardised procedure so could be easily replicated and used counterbalancing to eliminate order effect
+ supports gregory’s theory that perception is influenced by prior knowledge
- unrepresentative sample cannot be generalised
- low ecological validity as the task and setting were artificial
- participants were volunteers
