Perceiving and Recognizing Objects

Question 1

texture segmentation

Answer 1

Carving an image into regions of common texture properties.

Question 2

global superiority effect

Answer 2

The finding in various experiments that the properties of the whole object take precedence over the properties of parts of the object.

Question 2

viewpoint invariance

Answer 2

1. A property of an object that does not change when observer viewpoint changes. 2. A class of theories of object recognition that proposes representations of objects that do not change when viewpoint changes.

Question 3

fusiform face area (FFA)

Answer 3

A region of extrastriate visual cortex in humans that is specifically and reliably activated by human faces.

Question 4

agnosia

Answer 4

A failure to recognize objects in spite of the ability to see them. Agnosia is typically due to brain damage.

Question 4

homologous regions

Answer 4

Brain regions that appear to have the same function in different species.

Question 5

recognition-by-components model

Answer 5

Biederman’s model of object recognition, which holds that objects are recognized by the identities and relationships of their component parts.

Question 5

symmetry

Answer 5

A rule for figure-ground assignment stating that symmetrical regions are more likely to be seen as figure.

Question 7

congenital prosopagnosia

Answer 7

A form of “face blindness” apparently present from birth, as opposed to “acquired prosopagnosia,” which would typically be the result of an injury to the nervous system.

Question 8

Necker cube

Answer 8

An outline that is perceptually bi-stable. Unlike the situation with most stimuli, two interpretations continually battle for perceptual dominance.

Question 9

heuristic

Answer 9

A mental shortcut.

Question 9

middle (midlevel) vision

Answer 9

A loosely defined stage of visual processing that comes after basic features have been extracted from the image (low-level, or early, vision) and before object recognition and scene understanding (high-level vision).

Question 9

middle temporal area (MT)

Answer 9

An area of the brain thought to be important in the perception of motion.

Question 9

structuralism

Answer 9

A school of thought believing that complex objects or perceptions could be understood by analysis of the components.

Question 10

Bayesian approach

Answer 10

A way of formalizing the idea that our perception is a combination of the current stimulus and our knowledge about the conditions of the world—what is and is not likely to occur. The Bayesian approach is stated mathematically as Bayes’ theorem—P( A|O) = P( A) × P(O| A)/P(O)—which enables us to calculate the probability (P ) that the world is in a particular state ( A) given a particular observation (O).

Question 11

extrastriate body area (EBA)

Answer 11

A region of extrastriate visual cortex in humans that is specifically and reliably activated by images of the body other than the face.

Question 12

figure-ground assignment

Answer 12

The process of determining that some regions of an image belong to a foreground object (figure) and other regions are part of the background (ground).

Question 13

double dissociation

Answer 13

The phenomenon in which one of two functions, such as hearing and sight, can be damaged without harm to the other, and vice versa.

Question 15

feed-forward process

Answer 15

A process that carries out a computation (e.g., object recognition) one neural step after another, without need for feedback from a later stage to an earlier stage.

Question 16

Gestalt

Answer 16

In German, literally “form.” In perception, a school of thought stressing that the perceptual whole could be greater than the apparent sum of the parts.

Question 17

accidental viewpoint

Answer 17

A viewing position that produces some regularity in the visual image that is not present in the world (e.g., the sides of two independent objects lining up perfectly).

Question 18

parallelism

Answer 18

A rule for figure-ground assignment stating that parallel contours are likely to belong to the same figure.

Question 20

Gestalt grouping rules

Answer 20

A set of rules describing which elements in an image will appear to group together. The original list was assembled by members of the Gestalt school of thought.

Question 20

lesion

Answer 20

1. (n) A region of damaged brain. 2. (v) To destroy a section of the brain.

Question 20

structural description

Answer 20

A description of an object in terms of the nature of its constituent parts and the relationships between those parts.

Question 22

ambiguous figure

Answer 22

A visual stimulus that gives rise to two or more interpretations of its identity or structure.

Question 22

good continuation

Answer 22

A Gestalt grouping rule stating that two elements will tend to group together if they seem to lie on the same contour.

Question 23

similarity

Answer 23

A Gestalt grouping rule stating that the tendency of two features to group together will increase as the similarity between them increases.

Question 25

geon

Answer 25

In Biederman’s recognition-by-components model, any of the “geometric ions” out of which perceptual objects are built.

Question 27

naïve template theory

Answer 27

The proposal that the visual system recognizes objects by matching the neural representation of the image with a stored representation of the same “shape” in the brain.

Question 28

prosopagnosia

Answer 28

An inability to recognize faces.

Question 29

parahippocampal place area (PPA)

Answer 29

A region of extrastriate visual cortex in humans that is specifically and reliably activated more by images of places than by other stimuli.

Question 32

extrastriate cortex

Answer 32

The region of cortex bordering the primary visual cortex and containing multiple areas involved in visual processing.

Question 34

inferotemporal (IT) cortex

Answer 34

Part of the cerebral cortex in the lower portion of the temporal lobe, important in object recognition.

Question 35

relatability

Answer 35

The degree to which two line segments appear to be part of the same contour.

Question 36

illusory contour

Answer 36

A contour that is perceived even though nothing changes from one side of it to the other in an image.

Question 37

entry-level category

Answer 37

For an object, the label that comes to mind most quickly when we identify it (e.g., “bird”). At the subordinate level, the object might be more specifically named (e.g., “eagle”); at the superordinate level, it might be more generally named (e.g., “animal”).

Question 38

surroundedness

Answer 38

A rule for figure-ground assignment stating that if one region is entirely surrounded by another, it is likely that the surrounded region is the figure.

Question 39

proximity

Answer 39

A Gestalt grouping rule stating that the tendency of two features to group together will increase as the distance between them decreases.

Question 40

nonaccidental feature

Answer 40

A feature of an object that is not dependent on the exact (or accidental) viewing position of the observer.