Chapter 4: Objects--Vocab

Question 1

accidental viewpoint

Answer 1

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 2

agnosia

Answer 2

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

Question 3

ambiguous figure

Answer 3

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

Question 4

Bayesian approach

Answer 4

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 5

congenital prosopagnosia

Answer 5

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 6

double dissociation

Answer 6

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 7

entry-level category

Answer 7

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 8

extrastriate body area (EBA)

Answer 8

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

Question 9

extrastriate cortex

Answer 9

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

Question 10

feed-forward process

Answer 10

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 11

figure-ground assignment

Answer 11

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 12

fusiform face area (FFA)

Answer 12

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

Question 13

geon

Answer 13

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

Question 14

Gestalt

Answer 14

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 15

Gestalt grouping rules

Answer 15

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 16

global superiority effect

Answer 16

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

Question 17

good continuation

Answer 17

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

Question 18

heuristic

Answer 18

A mental shortcut.

Question 19

homologous regions

Answer 19

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

Question 20

illusory contour

Answer 20

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

Question 21

inferotemporal (IT) cortex

Answer 21

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

Question 22

lesion

Answer 22

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

Question 23

middle (midlevel) vision

Answer 23

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 24

middle temporal area (MT)

Answer 24

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

Question 25

naïve template theory

Answer 25

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 26

Necker cube

Answer 26

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

Question 27

nonaccidental feature

Answer 27

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

Question 28

parahippocampal place area (PPA)

Answer 28

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

Question 29

parallelism

Answer 29

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

Question 30

prosopagnosia

Answer 30

An inability to recognize faces.

Question 31

proximity

Answer 31

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

Question 32

recognition-by-components model

Answer 32

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

Question 33

relatability

Answer 33

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

Question 34

similarity

Answer 34

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

Question 35

structural description

Answer 35

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

Question 36

structuralism

Answer 36

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

Question 37

surroundedness

Answer 37

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 38

symmetry

Answer 38

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

Question 39

texture segmentation

Answer 39

Carving an image into regions of common texture properties.

Question 40

viewpoint invariance

Answer 40

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.