Chapter 4: Perceiving and Recognizing Objects

Question 1

extrastriate cortex

Answer 1

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

Question 2

lesion

Answer 2

In reference to neurophysiology,

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

Question 3

agosia

Answer 3

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

Question 4

inferotemporal (IT) cortex

Answer 4

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

Question 5

homologous regions

Answer 5

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

Question 6

feed-forward process

Answer 6

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 7

middle (midlevel) vision)

Answer 7

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 8

illusory contour

Answer 8

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

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

Gestalt

Answer 10

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

Question 11

Gestalt grouping rules

Answer 11

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 12

good continuation

Answer 12

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

Question 13

closure

Answer 13

In reference to perception, closure is the name of a Gestalt principle that holds that a close contour is preferred to an open contour.

Question 14

texture segmentation

Answer 14

Carving an image into regions of common texture properties.

Question 15

similarity

Answer 15

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

Question 16

proximity

Answer 16

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

Question 17

parallelism

Answer 17

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

Question 18

symmetry

Answer 18

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

Question 19

ambiguous figure

Answer 19

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

Question 20

Necker cube

Answer 20

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

Question 21

accidental viewpoint

Answer 21

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 22

figure-ground assignment

Answer 22

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 23

surroundedness

Answer 23

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 24

relatability

Answer 24

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

Question 25

heuristic

Answer 25

A mental shortcut.

Question 26

nonaccidental feature

Answer 26

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

Question 27

global superiority effect

Answer 27

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

Question 28

Bayesian approach

Answer 28

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) x 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 29

subtraction method

Answer 29

In functional magnetic imaging, brain activity is measured in two conditions: one with and one without the involvement of the mental process of interest. Subtracting the two conditions shows regions of brain specifically activated by that process.

Question 30

parahippocampal place area (PPA)

Answer 30

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

Question 31

fusiform face area (FFA)

Answer 31

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

Question 32

extrastriate body area (EBA)

Answer 32

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

Question 33

naive template theory

Answer 33

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

Question 34

structural description

Answer 34

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

Question 35

geon

Answer 35

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

Question 36

recognition-by-components model

Answer 36

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

Question 37

viewpoint invariance

Answer 37

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 38

entry-level category

Answer 38

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 39

prosopagnosia

Answer 39

An inability to recognize faces.

Question 40

double dissociation

Answer 40

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

Question 41

congenital prosopagnosia

Answer 41

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