Perception Flashcards
Gibson’s direct theory of perception
The environment gives us all the information we need.
Perception doesn’t draw on past experience (the influence of nature)
Gregory’s constructivist theory of perception
We use past experiences to make sense of the world.
Proposes that sensation and perception are not the same.
Sensation definition
Physical stimulation of the five senses processed by the sense receptors.
Perception definition
Brain interpreting and storing sensory information.
difference between sensation and perception
sensation is detecting a stimulus
perception is interpreting what it means.
Theories of perception
Perception theories differ, there is:
Gregory’s constructivist theory - sees the difference between perception and sensation.
Gibson’s direct theory - Gibson does not see the difference between perception and sensation.
Ponzo illusion
misinterpreted depth cue. Perceives horizontal line higher up as longer.
Muller-Lyer illusion
Misinterpreted depth cue. Two vertical lines the same length. Line with outgoing fins interpreted as longer.
Rubin’s vase
Ambiguous figure. Face and vase. Both are correct, brain switches back and forth from both.
Ames room
Misinterpreted depth cue. Room the shape of a trapezoid, people seen as different sizes even though they are the same.
binocular depth cues meaning
depth cues with two eyes
monocular depth cues meaning
depth cues with one eye
cues definition
information about movement, distance, etc
constancies definition
see an object as the same from different angles and distances.
Types of binocular depth cues
Retinal disparity and convergence
Retinal disparity meaning
difference between the view of the left and right eye gives informations to the brain about depth and distance.
Convergence meaning
Eyes point closer together when an object is close. Muscles work harder so know depth and distance.
types of monocular depth cues
Height in plane, relative size, occlusion and linear perspective.
Height in plane meaning
objects higher up appear further away.
Relative size meaning
smaller objects appear further away.
Occlusion meaning
If one object obscures another part of an object, it is seen as closer.
Linear perspective meaning
parallel lines appear closer as they become more distant.
size constancy meaning
objects perceived as a constant size despite size on the retina changing with distance.
fiction meaning
seeing something that is not there.
misinterpreted depth cues meaning
Objects apparently in the distance scaled up by the brain to look normal size, causes visual illusions.
Ambiguous figures meaning
two possible interpretations of the image, brain can’t decide which is correct.
Gibson - sufficient information for direct proportion meaning
sensation and perceptions are the same.
The eyes detect everything we need without having to make interferences.
Gibson - Optic flow patterns meaning
when moving, things in the distance appear stationary and everything else rushes past. Provides perceptual information about speed and distance.
Gibson - motion parallax meaning
A monocular depth cue, when we are moving past them, closer objects appear to move faster than objects that are further away.
Provide perceptual information about speed and distance.
Gibson - the influence of nature
perception is inborn not learned.
Gregory - perception as a construction meaning
brain uses incoming information and information we already know to form a hypothesis/guess
Gregory - Inference meaning
Brain fills in the gaps to create a conclusion about what is being seen.
Gregory - Visual cues meaning
Visual illusions occur because of incorrect conclusions from visual cues.
Gregory - Past experience, the role of nurture meaning
Perception is learned from experience.
The more we interact the more sophisticated our perception.
Gibson’s theory - Evaluation points
Real-world meaning - research was on WW2 pilots, so relevant to daily life.
Theory struggles to explain visual illusions - perceptions are seen as accurate but illusions trick the brain, so the theory is incomplete.
Support for the role of nature - Gibson and Walk showed that few infants crawl off of a visual cliff, which shows that they are born with depth perception.
Gregory’s theory - evaluation points
Support of research in different cultures - people interpret visual cues differently (e.g., Hudson’s study) showing experience effects perception.
Visual illusions - Gregory’s theory used 2D illusions which are artificial, so don’t apply to the real world.
Culture definition
social world we live in (culture) affects what our senses pick up.
Hudson’s study method
Showed 2D pictures to black and white school children, schooled and unschooled.
Children were asked what was nearer the man, the elephant or the antelope?
Hudson’s study aim
To find out whether different cultures perceive depth cues in 2D images differently.
Hudson’s study results
Black and white schooled participants more likely to see depth than unschooled participants.
White schooled participants more likely to perceive depth than black schooled participants.
Hudson’s study conclusions
Different cultures use depth cues differently, so have a different perceptual set.
Hudson’s study evaluation points
Cross-cultural research - language differences could’ve made method used unclear, so validity is affected.
Problems with the method - The way the pictures were represented ay have confused participants, affecting findings.
Poor design - Early cross-cultural studies were poorly designed (no control group) causing findings to lack validity.
factors affecting perception
emotion, expectation, culture and motivation.
McGinnie’s study aim
to know if anxiety-provoking things are noticed more than neutral things.
McGinnie’s study method
Students shown natural and ‘taboo’ words. Had to say word out loud.
Emotional arousal measured through GSR.
McGinnie’s study results
Took longer to say taboo words. Taboo words gave bigger change in GSR.
McGinnie’s study conclusion
Emotion affects perceptual set, in this case perceptual defence.
McGinnie’s study Evaluation points
Objective measurement - GSR is a scientific measurement to measure emotion, better than rating scales.
Embarrassment not defence - delayed recognition may just be embarrassment not perceptual defence.
Gilchrist and Nesburg study aim
To find out if food deprivation affects the perception of food.
Gilchrist and Nesburg study method
Hungry (no food for 20 hours) and not hungry participants shown a slide of a meal. Had to adjust light level of slide shown.
Gilchrist and Nesburg study results
Perceived food as brighter the longer the participant was deprived of food.
Gilchrist and Nesburg study conclusion
Sensitivity greater when deprived of food.
Hunger is a motivating factor that affects perception of food.
Gilchrist and Nesburg study evaluation points
Support from similar studies - Sandford’s study found similar results which strengthens the validity of the conclusions.
Ethical issues - depriving people of food causes discomfort, a case of physical harm.
Not like everyday life - It is difficult to draw conclusions from a study that is inconsistent.
Bruner and Minturn’s study aim
to find out if an ambiguous figure is seen differently if context is changed.
Bruner and Minturn’s study method
Participants shown a sequence of either numbers or letters with an ambiguous figure in the middle.
Bruner and Minturn’s study results
Those who saw letters said B.
Those who saw numbers said 13.
Bruner and Minturn’s study conclusions
Shows expectation if affected by by the context the figure is presented.
Bruner and Minturn’s study evaluation points
Artificial task - Ambiguous figures are designed to trick perception, so task lacks validity.
Independent groups design - Participant variables may have caused the difference in results not expectation.
Real-world application - The study can explain the sometimes serious mistakes people make in the real world.
