Visual Attention Chp 7 (Perception)

divided attention

When you pay attention to several things at once. (Driving and paying attention to other cars, traffic signals, pedestrians).

selective attention

Focusing on specific objects while ignoring others. (Driving and paying attention to traffic signals but ignore store signs).

saccades

quick motion of the eyes from one place to another. (eye movement)

fixations

pauses of the eyes; this occurs where the person is attending.

smooth pursuit movements (SPM)

tracking a moving object. (watching & following a moving baseball).

Binding

the process by which features (like color, form, motion, & location) are combined to produce our perception of a coherent object. (ex: noticing all components of a red cardinal flying).

illusory conjunction

when features associated with one object get incorrectly associated with another object.

Feature Integration Theory (Treisman & Gelade, 1980) FIT

A theory of binding that explains illusory conjunctions, two stages; Preattentive stage: features are separate, & Attentive stage: focusing attention on particular object causes the features to bind together

inattentional blindness

when a stimulus that is not attended is not perceived, even though the person is looking directly at it

change blindness

difficulty in detecting changes in scene, often occurs if change does not affect overall meaning of scene.

change blindness blindness

when people think that they would be able to notice the changes in a scene.

Levin and Simons (1997), had participants watch a film, told half participants about changes that would occur in the film. 83% of participants said they would notice changes in film, after the film only 13% noticed a difference.

Top-Down Processing

perception that is based on higher level of COGNITIVE processes, like beliefs and expectations (a.k.a, knowledge based processing)

Bottom-Up Processing

perception that is based on the information in the stimulus on the retina. ( a.k.a. data-based processing)

feature search process

target can be found by looking for a single feature (like color, size, or orientation). (ex: searching for a blue sock among black socks and white underwear). Results in a parallel search.

parallel search process

all items are processed at the same time to quickly find the target because the target “pops out”.

conjunction search process

target is found by looking for a combination of two or more features on the same stimulus. (ex: searching for a gray sock among white socks and gray and white underwear). Results in performing a serial search process

serial search process

items are exclaimed one by one until the target is found, or all items are checked. Takes longer

Balint’s Syndrome

People who have a narrow visual attention field. Contains 3 characteristics: simultagnosia, optic ataxia, optic apraxia.

Simultagnosia

inability to recognize more than one object shown at the same time, cannot notice outer areas of visual field. (ex: recognizing a pig and a cow on a farm but cant recognize scene of farm).

optic ataxia

inability to move the hand to an object by using visual information. (ex: cannot point to or reach for objects).

optic apraxia

inability to voluntarily control the gaze. (ex: when we look toward new object--> eye movement is inaccurate).

unilateral neglect

a failure to attend to or report information appearing on the left side of space despite intact sensory processing and visual acuity. (Cause: damage to parietal lobe, stroke).

Covert attention

Paying attention to something else without directing a sense organ at stimulus.

Overt attention

directing a sense organ at a stimulus, fixation of eyes on a word.

Scene-based Guidance

Information in our understanding of scenes that help us find specific objects in the scenes helps you speed your conclusion to search tasks. (ex: seeing a toilet and then noticing toilet paper).

Anchor Points

objects in predictable locations that tell you about the location of other objects. (A scene-based guidance tool)

attentional blink

Not perceiving or responding to the second of two different target stimuli amid a rapid stream of districting stimuli if you find the first target 200-500 ms before the second stimuli is presented. (ex: while noticing a car Infront of you swerve lanes but not noticing a pedestrian crossing the road).