Perception Flashcards
What is the retina?
The light sensitive later at the back of the eye, it is made up of rods and cones.
What is perception?
The way the brain makes sense of the visual image detected by the Brain.
What are rods?
Light sensitive cells in the retina that respond even in dim light.
What are cones
Light sensitive cells in the retina that can detect colour
What is the optic nerve
Bundle of nerves that lead out from the retina, carries info from rods and cones to the brain.
What is the blind spot
The area of the retina where the optic nerve leaves. It has no rods and cones so cannot detect light.
What is the optic chiasma
The cross shape where some of the information from the left and the right eye cross over to pass into the opposite side of the brain.
What is the visual cortex
Area at the back of the brain that interprets visual information
What does the visual cortex allow
Allows us to understand shapes and distances and fills in the gap left by the blind spot in each eye.
What are depth cues
The visual clues that we use to understand depth or distance
What are monocular depth cues?
Information about distance that comes from one eye
Name some monocular depth cues
Texture gradient Superimposition Height in plane Linear perspective Relative size Linear perspective
What are binocular depth cues
Information about distance that needs two eyes
Name some binocular depth cues
Stereopsis
What is size constancy
Perceiving an object as the same size even when it’s distance is changing
What is relative size
Smaller objects are perceived as further away than larger ones
What is texture gradient
An area with a detailed pattern perceived to be nearer than one with less detail
What is hight in plane
An object closer to the horizon is perceived as further away
What is superimposition
A partly hidden object must be further away than the object covering it
What is linear perspective?
Parallel lines appear to converge in the distance
What is stereopsis
A binocular depth cue. The greater the difference between the view seen in the left and the right eye = the closer the viewer is looking
Name the gestalt laws
Figure ground Similarity Proximity Continuity Closure
What is figure ground
A small complex object is seen separate from a background
What is the law of similarity
Figures sharing size shape or colour are grouped
What is the law of proximity
Objects which are close together are perceived as related
What is the law of continuity
Straight lines curves and shapes are perceived to carry on being the same
What is the law of closure
Lines/shapes are perceived as complete figures even if parts are missing
What is a visual illusion
A conflict between reality and what we perceive
What is a fiction
When a figure is perceived even though it is not present in the stimulus
What is an illusionary contour
A boundary that is perceived in a figure but is not present in the stimulus
What is a motion after effect
Caused by paying more attention to movement in one direction and perceiving movement in the opposite direction afterwards
What is a colour after effect
Caused by focusing on a coloured stimulus and perceiving opposite colours afterwards
What is an ambiguous figure
A stimulus with two possible interpretations in which it is impossible to view both at the same time
What is a distortion illusion
Where our perception is deceived by some stimulus, affecting shape or size of an object
Evaluate gestalt a theory of illusions
Can explain fictions but cannot explain the Kanizsa triangle as its explanation would mean that we would see a 6 pointed star but we see two triangles.
Provides good explanation for ambiguous figures.
Evaluate Gregory’s theory of illusions
Good explanation for distortions. if angled lines are used as depth cues it can explain many illusions.
Cannot explain versions of muller lyer.
Can explain some fictions as background lines appear closer to horizon= further away
What is a schema?
A framework of knowledge about an event, object of group that has affected our perception, helping us to organise information and recall what we have seen.
What is perceptual set
The tendency to notice some things more than others. Caused by experiences, context or expectations
What is the independent variable
Factor which is changed in an experiment
What is the dependent variable
The factor which is measured in an experiment.
What was the aim of palmers study
If context affected perception
What was the procedure of palmers experiment
Lab experiment. Showed participants a visual scene of a kitchen. Participants were shown 3 objects (mail box, loaf of bread and a drum) briefly to identify. There were 4 conditions of the context: appropriate - bread
Inappropriate but similar shape to appropriate - mailbox
Inappropriate - drum
No context
What were the results of palmers experiment
Participants correctly identified the most objects after seeing an appropriate context and the least after seeing an inappropriate context.
What was the conclusion for palmers experiment?
People have perceptual set based on context which affects how accurately they recognise objects.
What is the IV for palmers
Whether the object was appropriate, inappropriate-similar, inappropriate-different or no context
What was the DV for palmers
The number of correctly identified items
Name 2 strengths of palmers study
Clear instructions where given so participants knew exactly what to do.
Data from two participants were not used cause they’d forgotten their glasses = could have affected results
Name 2 weaknesses of palmers study
As participants were told what they were doing they might have tried harder to please experimenter.
As some data couldn’t be used there were fewer results.
What does serial reproduction mean
A task where information is passed from one participant to the next in a series.
What does repeated reproduction mean
A task where participants are given a story to remember. They then recall it several times after time delays.
What was the aim of Bartlett’s study
To investigate how information changes with each reproduction and to find out why.
What was the procedure for Bartlett’s study
Two groups of participants were used.
Serial reproduction group - first participant was given ‘war of the ghosts’ to read alone twice. After 15-30 mins they told the story to the next participant. This cycle continued.
In repeated reproductions participants were given the same story to read twice. They then told the story 15 minutes later. Reproductions were done at 20 hours, 8 days, 6 months and 20 years.
What were the results of Bartlett’s study
Very few participants recalled the story accurately. He found the following pattern of errors: form, details, simplification and addition.
What was Bartlett’s conclusion
Unfamiliar material changes when it is recalled, it becomes shorter, simpler and more stereotyped. Due to effect of schemes on memory.
Name 2 strengths of Bartlett’s study
Both repeated and serial reproduction where done many times.
Other stories were also used and showed similar results.
Name two weaknesses for Bartlett’s study
By chiseling unfamiliar material, Bartlett couldn’t be sure that the changes would be the same for familiar information.
Bartlett did not always test participants after the same time intervals, changes over time cannot be compared fairly.
What was the IV for Bartlett’s study
Whether the participants used serial or repeated reproduction
What was the DV for Bartlett’s study
Whether the story changed
What is the aim of carmichaels experiment
To find out whether words shown with pictures affect the way we remember the pictures
What is the procedure for carmichaels experiment
Used a lab experiment in which 95 participants were shown 12 pics. Between each pic the experimenter would say what they pic resembled from either list 1 or 2. A control group heard no verbal labels participants where then asked to draw the pictures they had seen. Drawings were compared to originals.
What was the IV of carmichaels experiment
Which word they heard from list 1 or 2
What was the DV of carmichaels experiment
How similar the pictures the participants drew where to the originals
What were the results of carmichaels experiment
The drawings from people who heard list 1 were different to those who had heard list 2. Drawings resembled the words.
What was the conclusion of carmichaels experiment
That memory for pictures is reconstructed and the verbal context in which the drawings are learned affects recall as the memory of the word alters the way the picture is presented.
Name two strengths of carmichaels experiment
By using two different lists it showed that the verbal labels affected people’s drawings.
Having 12 pics and many participants gave them lots of evidence. Could be sure findings were not a fluke.
Name two weaknesses of carmichaels experiment
In real life things are not as ambiguous.
Prentice tested the effect of verbal labels on recognition and found that verbal labels didn’t affect it. Means carmichaels findings do not apply widely.
What is the definition of an experiment
A way to find out whether one factor affects another. Measures participants performance in two or more conditions
What is the definition for an experimental design
The way that participants are used in different conditions.
What is an independent groups design and what is its definition
An experimental design. Different participants are used in each condition In an experiment.
What is a repeated measures design and what is its definition.
An experimental design. Same participants are used in all the conditions in an experiment.
What is the definition of a hypothesis
Statement stating what an experimenter expects to happen and how the IV will affect the DV.
What is the definition of controls
Ways to keep a variable constant in all conditions of an experiment.
What is the mode
Most common score or response in a set
What are descriptive statistics
Ways to summarise results from a study. They can show a typical or average score.
What is the median
An average that is the middle number in a set of scores. Where they are put in order of smallest to largest.
What is the mean.
An average that is calculated by adding up all scores and then dividing by the number of scores
What is the range
A way to show how spread out a set of results are by looking at the biggest and smallest scores
What are ethical issues
Potential psychological or physical risks for people in experiments.
Name two ethical issues and describe what they mean
Informed consent - participants right to know what will happen in an experiment, it’s aims, before agreeing to participate.
Right to be withdraw - Participants right to leave a study at any time and their ability to do so.
What is the definition of ethical guidelines
Advice to help psychologists solve ethical issues.
Name a good method psychologists can use in order to give informed consent.
Giving participants a summary about what will happen in the study. The participant can then chose whether to participate or not.
Why for studies which take place in public places, parks, and is it hard to get informed consent.
It would be too hard to ask everyone if they are happy to participate. Instead researchers can ask colleges if they think people would mind.
What is one problem researchers face with ethical issues.
Ethics can sometimes conflict with controls, telling someone the main aim of the study could change the way they react within it.
Name two strengths of experiments
When participants come to the lab their right to withdraw can be explained.
The DV can be measured.
Name two weaknesses of experiments
Experiments should try to represent real life as much as possible, labs are unfamiliar to participants - may behave oddly compared to normal.
Sometimes experiments need to hide the aim of the study as otherwise they might behave differently.
What is the definition of eyewitness
Somebody who sees a crime or aspects of a crime and who helps the police to find out what has happened or to catch whoever was responsible.
How do schemas affect eyewitness memory
Schemas affect the way we perceive things. We might think we see something based on our perception, eg stereotypes.
