Sensation And Perception Ch. 8 Attention And Scene Perception

Front 1

attention

Back 1

Any of the very large set of selective processes in the brain. To deal with the impossibility of handling all inputs at once, the nervous system has evolved mechanisms that are able to restrict processing to a subset of things or places or ideas or moments in time.

Front 2

attentional blink

Back 2

The difficulty in perceiving and responding to the second of two target stimuli amid a rapid stream of distracting stimuli if the observer has responded to the first target stimulus within 200 to 500 ms before the second stimulus is presented.

Front 3

attentive

Back 3

Referring to processing that requires the deployment of attention to a stimulus or location. Compare preattentive.

Front 4

binding problem

Back 4

The challenge of tying different attributes of visual stimuli (e.g., color, orientation, motion), which are handled by different brain circuits, to the appropriate object so that we perceive a unified object (e.g., red, vertical, moving right).

Front 5

change blindness

Back 5

The failure to notice a change between two scenes. If the change does not alter the gist, or meaning, of the scene, quite large changes can pass un­noticed.

Front 6

conjunction search

Back 6

Search for a target defined by the presence of two or more attributes (e.g., a red, vertical target among red horizontal and green vertical distractors). Compare feature search.

Front 7

contralesional field

Back 7

The visual field on the side opposite to a brain lesion (e.g., points to the left of fixation are contralesional to damage to the right hemisphere of the brain). Compare ipsilesional field

Front 8

covert attentional shift

Back 8

A shift of attention in the absence of corresponding movements of the eyes. Compare overt attentional shift.

Front 9

cue

Back 9

A stimulus that might indicate where (or what) a subsequent stimulus will be. Cues can be valid (correct information), invalid (incorrect), or neutral (uninformative).

Front 10

distractor

Back 10

In visual search, any stimulus other than the target.

Front 11

extinction

Back 11

In visual attention, the inability to perceive a stimulus in the presence of another stimulus, typically in a comparable position in the other visual field. See neglect.

Front 12

feature integration theory

Back 12

Anne Treisman’s theory of visual attention, which holds that a limited set of basic features can be processed in parallel preattentively, but that other properties, including the correct binding of features to objects, require attention. Compare guided search theory.

Front 13

feature search

Back 13

Search for a target defined by a single attribute, such as a salient color or orientation. Compare conjunction search

Front 14

fusiform face area

Back 14

An area in the fusiform gyrus of human extrastriate cortex that responds preferentially to faces in fMRI studies. Compare parahippocampal place area.

Front 15

guided search theory

Back 15

A model of visual search that holds that early (preattentive) visual processes can guide the subsequent deployment of attention. Compare feature integration theory.

Front 16

illusory conjunction

Back 16

An erroneous combination of two features in a visual scene—for example, seeing a red X when the display contains red letters and Xes, but no red Xes.

Front 17

ipsilesional field

Back 17

The visual field on the same side as a brain lesion. Compare contralesional field

Front 18

limited-capacity parallel process

Back 18

A process that is capable of handling many stimuli at one time but that processes each item more slowly as the number of items increases. Com­pare serial self-terminating search

Front 19

neglect

Back 19

In visual attention, the inability to attend to or respond to stimuli in the contralesional visual field (typically, neglect of the left field after right parietal damage). Also, neglect of half of the body or half of an object. Compare extinction

Front 20

overt attentional shift

Back 20

A shift of attention accompanied by corresponding movements of the eyes. Compare covert attentional shift

Front 21

parahippocampal place area

Back 21

A region of cortex in the temporal lobe of humans that appears to respond with particular strength to images of places (as opposed to isolated objects). Compare fusiform face area.

Front 22

parallel

Back 22

In visual attention, referring to the processing of multiple stimuli at the same time.

Front 23

parietal lobe

Back 23

A lobe of each cerebral hemisphere that lies toward the top of the brain between the frontal and occipital lobes.

Front 24

preattentive

Back 24

Referring to the processing of a stimulus that occurs before selective attention is deployed to that stimulus. Compare attentive

Front 25

rapid serial visual presentation (RSVP)

Back 25

An experimental procedure in which a stream of stimuli appear at one location (typically fixation) at a rapid rate (typically about eight per second).

Front 26

reaction time (RT)

Back 26

A measure of the time from the onset of a stimulus to a response.

Front 27

response enhancement

Back 27

One possible effect of attention on the response of neurons. A neuron responding to an attended stimulus might just give a bigger response.

Front 28

salience

Back 28

The vividness of a stimulus relative to its neighbors.

Front 29

serial self-terminating search

Back 29

A search from item to item, ending when a target is found. Compare limited-capacity parallel process

Front 30

set size

Back 30

The number of items in a visual display.

Front 31

sharper tuning

Back 31

One possible effect of attention on the response of neurons. Attention might cause a neuron to respond more precisely. For example, a neuron that responds to lines with orientations from –20° to +20° might come to respond to ±10° lines.

Front 32

simultagnosia

Back 32

An inability to perceive more than one object at a time. Simultagnosia is a consequence of bilateral damage to the parietal lobes (Balint syndrome).

Front 33

spatial layout

Back 33

Description of the structure of a scene (e.g., enclosed, open, rough, smooth) without reference to the identity of the specific objects in the scene.

Front 34

stimulus onset asynchrony (SOA)

Back 34

The time between the onset of one stimulus and the onset of another.

Front 35

target

Back 35

The goal of a visual search. Compare distractor

Front 36

visual search

Back 36

Looking for a target in a display containing distracting elements.

Front 37

visual-field defect

Back 37

A portion of the visual field with no vision or with abnormal vision, typically resulting from damage to the visual nervous system.