Topic A - Perception (Key Words) Flashcards
Perception
The way the brain makes sense of the visual image detected by the eyes.
Retina
The light-sensitive layer at the back of the eye. It is made up of nerve cells called rods and cones.
Rods
Light-sensitive cells in the retina that respond even in dim light.
Cones
Light-sensitive cells in the retina that can detect color.
Optic nerve
Bundle of nerve cells that leads out from the retina at the back of the eye. It carries information from the rods and cones to the brain.
Blindspot
The area of the retina where the optic nerve leaves. It has no rods of cones so cannot detect light.
Optic chiasma
The cross-shape where some of the information from the left and right eye crosses over to pass into the opposite side of the brain.
Visual cortex
The area at the back of the brain that interprets visual information.
Depth cues
The visual ‘clues’ that we use to understand depth or distance.
Monocular depth cues
Information about distance that comes from one eye, such as superimposition, relative size, texture gradient, linear perspective and height in the plane.
Binocular depth cues
Information about distance that needs two eyes, such as stereopsis.
Size constancy
We perceive an object as the same size when its distance from us changes.
Relative size
Smaller objects are perceived as further away than larger ones.
Texture gradient
An area with a detailed pattern is perceived to be nearer than one with less detail.
Height in the plane
Objects closer to the horizon are perceived to be more distant than ones below or above the horizon.
Superimposition
A partly hidden object must be further away than the object covering it.
Linear perspective
Parallel lines appear to converge in the distance.
Stereopsis
The greater the difference between the view seen by the left eye and the right eye, the closer the viewer is looking.
Gestalt laws
Perceptual rules that organize stimuli.
‘The whole is worth more than the sum of the parts’
Figure-ground
A small, complex, symmetrical object (the figure) is seen as separate from a background (the ground).
Similarity
Figures sharing size, shape or color are grouped together with other things that look the same.
Proximity
Objects which are close together are perceived to be related.
Continuity
Straight lines, curves and shapes are perceived to carry on being the same.
Closure
Lines or shapes are perceived as complete figures, even if parts are missing.
Visual illusion
A conflict between reality and what we perceive.
Fiction
An illusion caused when a figure is perceived even though it is not present in the stimulus.
Illusory contour
A boundary (edge) that is perceived in a figure but is not present in the stimulus.
Motion after-effect
An illusion caused by paying attention to movement in one direction and perceiving movement in the opposite direction immediately afterwards.
Color after-effect
An illusion caused by focusing on a colored stimulus and perceiving opposite colors immediately afterwards.
Ambiguous figure
A stimulus with two possible interpretations, in which is is possible to perceive only one of the alternatives at any time.
Distortion illusion
Where our perception is deceived by some aspect of the stimulus. This can affect the shape or size of an object.
Independent variable
The factor which is changed by the researcher in an experiment to make two or more conditions.
Dependent variable
The factor which is measured in an experiment.
Schema
A framework of knowledge about an object, event or group of people that can affect our perception and help us organize information and recall what we have seen.
Perceptual set
The tendency to notice some things more than others. This can be caused by experience, context or expectations.
Serial reproduction
A task where a piece of information is passed from one participant to the next in a ‘chain’ or ‘series’. Differences between each version are measured.
Repeated reproduction
A task where the participant is given a story or picture to remember. They then recall it several times after time delays. Differences between each version are measured.
Reconstructive memory
Recalled material is not just a ‘copy’ of what we see or hear. Information is stored and when it is remembered it is ‘rebuilt’ so can be affected by extra information (like schemata) we might already have.
Experiment
A research method which measures participants’ performance in two or more conditions.
Experimental (participant) design
The way that participants are sued in different conditions in an experiment. They may all do all conditions or different participants may do each condition.
Independent groups design
Different participants are used in each condition in an experiment.
Repeated measures design
The same participants are used in all the condition in an experiment.
Hypothesis
A testable statement of the difference between the conditions in an experiment. It describes how the independent variable will affect the dependent variable.
Controls
Ways to keep variables constant in all conditions of an experiment.
Mode
An average that is the most common score or response in a set.
Descriptive statistics
Ways to summarize results from a study. They can show a typical or average score or how spread out the results are.
Bar chart
A graph with separate bars. Usually there is one bar for each condition in an experiment.
Median
An average that is the middle number in a set of scores when they are put in order from smallest to largest.
Mean
An average that is calculated by adding up all the scores in a set and dividing by the number of scores.
Range
A way to show how spread out a set of results is by looking at the biggest and smallest scores.
Ethical issues
Potential psychological or physical risks for people in experiments.
Informed consent
An individual’s right to know what will happen in an experiment, and its aims, before agreeing to participate.
Right to withdraw
A participant’s right to leave a study at any time and their ability to do so.
Ethical guidelines
Advice to help psychologists solve ethical issues.
Eyewitness
Somebody who sees a crime or aspects of a crime scene and who helps the police to find out what has happened or to catch whoever was responsible.
