5 Perceiving Objects And Scenes Flashcards
Viewpoint invariance
Objects that have properties that don’t change when viewed from different angles. The geons in the recognition-by-components theory of object perception are view invariant.
Inverse projection problem
Idea that a particular image on the retina could have been caused by an infinite number of different objects. Thus, the retinal image does not unambiguously specify a stimulus.
Gestalt psychology
Approach to psychology that focuses on developing principles of perceptual organization, proposing that “the whole differs from the sum of its parts.”
Structuralism
Approach to psychology, prominent in the 19th and early 20th centuries, the postulated that perceptions result from the summation of many elementary sensations. Gestalt approach to perception was, in part, a reaction to structuralism.
Sensations
Elementary elements that, according to this structuralists, combine to create perceptions.
Apparent movement
Illusion of movement that occurs between two objects separated in space when the objects are flashed rapidly on and off, one after another, separated by a brief time interval.
Illusionary contour
Contour that is perceived even though it is not present in the physical stimulus.
Laws of perceptual organization
Series of rules proposed by the Gestalt psychologists that specify how we organize small parts into holes. Some of these laws are common fate, familiarity, good continuation, good figure, nearness, and similarity. Most of these laws were originally proposed by the Gestalt psychologists, but modern researchers have proposed some additional laws.
Perceptual organization
Process by which small elements become perceptually grouped into larger objects.
Law of pragnanz
Gestalt law of perceptional organization that states that every stimulus pattern is seen in such a way that the resulting structure is as simple as possible. Also called law of good figure or the law of simplicity.
Law of similarity
Gestalt law stating that similar things appear to be grouped together.
Good continuation
Gestalt law of perceptual organization that states that points that, when connected, result in straight or smoothly curving lines are seen as belonging together, and outlines tend to be seen in such a way as to follow the smoothest path.
Law of proximity
Gestalt law of perceptual organization that states the things that are near to each other appear to be grouped together. Also called the law of nearness.
Principle of common region
Modern gestalt principle that states that elements that are within the same region of space appear to be grouped together.
Principle of uniform connectedness
Modern Gestalt principle that states that connected regions of a visual stimulus are perceived as a single unit.
Principle of synchrony
Modern principle of perceptual organization that states that visual events that occur at the same time will be perceived as belonging together.
Law of common fate
Gestalt law of perceptual organization that states that things that are moving in the same direction appear to be grouped together.
Law of familiarity
Gestalt law a lot of perceptional organization that states that things are more likely to form groups when the groups appeared familiar or meaningful.
Perceptual segregation
Perceptual organization in which one object is seen a separate from other objects.
Figure-ground segregation
Perceptual separation of an object from its background.
Figure
When an object is seen as separate from the background, it is called a figure.
Ground
In object perception, the background is called the ground.
Reversible figure-ground
Figure-ground pattern that perceptually reverses as it is viewed, so that the figure becomes the ground and the ground becomes a figure. The best-known reversible figure-ground pattern is Rubin’s vase-face pattern.
Border ownership
When to areas share a border, as occurs in figure-ground displays, the border is usually perceived as belonging to the figure.
Heuristics
In perception, a rule of thumb that provides “best guess” estimate of the identity of a particular stimulus.
Algorithm
Procedure that is guaranteed to result in the solution to a problem. For example, the procedures we learn for addition, subtraction, and long division are algorithms.
Recognition-by-components (RBC) theory
Theory of object perception proposed by Biederman, which proposes that we recognize objects by decomposing them into volumetric features call geons.
Geon
Volumetric features of vitamins recognition-by-components theory of object perception.
Non-accidental properties (NAPs)
Properties of edges in the retinal image that corresponds to the properties of edges in the three-dimensional environment. For example, a non-accidental property of a rectangular solid is three parallel edges. Non-accidental properties are visible from most viewpoints.
Accidental viewpoint
Viewpoint relative to an object that results in perception of an accidental (or rarely encountered) property of the object. For example, all three sides of the solid cube visible for most viewpoints, an accidental property – seeing only one side of the cube – occurs when the cube is seen from the accidental viewpoint of an end-on cue. This concept is associated with the recognition-by-components theory of object perception.
Discriminability
Generally, the ability to distinguish between one stimulus and another. In the recognition-by-components theory of object perception, discriminability is a property of geons, which indicates that each geon can be distinguished from other geons from almost all viewpoints.
Principle of componential recovery
Principle of the recognition-by-components model that states that we can rapidly and correctly identify an object if we can perceive its individual geons.
Scene
View of a real-world environment that contains (1) background elements and (2) multiple objects that are organized in a meaningful way relative to each other in the background.
Gist of a scene
General description of the scene. People can identify most scenes after viewing them for only a fraction of a second, as when they flicked rapidly from one TV channel to another.
Persistence of vision
Phenomenon in which perception of any stimulus persists for about 250 ms after the stimulus is physically terminated.
Masking stimulus
Visual pattern that, when presented immediately after visual stimulus, decreases a person’s ability to perceive the stimulus. This stops the persistence of vision and therefore limits the effective duration of the stimulus.
Global image features
Information that may enable observers to rapidly perceive the gist of the scene. Features associated with specific types of scenes include degree of naturalness, degree of openness, degree of roughness, degree of expansion, and color.
Regularities in the environment
Characteristics of the environment that occur regularly and in many different situations.
Physical regularities
Regularly occurring physical properties of the environment. For example, there are more vertical and horizontal orientations in the environment than a oblique (angled) orientations.
Oblique effect
Enhanced sensitivity to vertically and horizontally orientated visual stimuli. This effect has been demonstrated by measuring both perception and narrow responding.
Light-from-above heuristic
Assumption that light usually comes from above, which influences our perception of form in some situations.
Semantic regularities
Characteristics associated with the function carried out in different types of scenes. These characteristics are learned from experience. For example, most people are aware of the kinds of activities and objects that are usually associated with kitchens.
Theory of unconscious interference
Idea proposed by Helmholtz that some of our perceptions are the result of unconscious assumptions that we make about the environment.
Likelihood principle
Idea proposed by Helmholtz that we perceive the object that is most likely to have caused the pattern of stimuli we have received.
Bayesian inference
Statistical technique that takes probabilities into account.
Contextual modulation
When the neural response to stimulus is influenced by the context within which a stimulus occurs. This term has been used to refer to the situation in which are neuron’s response is influence by stimulation of an area outside of its receptor field.
Region-of-interest (ROI) approach
Procedure used in brain imaging in which subjects are pretested on the stimuli to be studied. This enables researchers to establish the precise location in the brain that they will be studying for each individual person.
Binocular rivalry
Situation in which two different images are presented simultaneously to the left and right eyes and perception alternate back and forth between the two images.
