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Reflexive Orienting

• Attention can be automatically “summoned” to a location at which an important event has occurred:– Loud noise– Motion– New Object

• We call this attentional capture

Transients

Reflexive Orienting

• What are some examples of reflexive orienting?– Posner Cue-Target Paradigm with a

stimulus cue (i.e. non-symbolic) at 50% validity

– Yantis “New Object” paradigm

Reflexive Orienting

• What are some examples of voluntary orienting?

Attention and Consciousness

• Sensory information must be attended for it to be entered into awareness

Attention and Consciousness

• The attention orienting mechanism can be confused leading to something called “change blindness”

Attention and Consciousness

• Change blindness

– Change blindness shows us that the feeling of being in a detailed visual environment is really just an illusion

– We only have access to the parts of the scene to which we have attended

Attention and Consciousness

• Change blindness

– Change blindness shows us that the feeling of being in a detailed visual environment is really just an illusion

– We only have access to the parts of the scene to which we have attended

– And that is often not very much!

• Visual Search: finding a single item in a cluttered visual scene

Visual Search

• Visual Search: finding a single item in a cluttered visual scene

Visual Search

• Is there a green square?

Visual Search

• Is there a green square?

Visual Search

• Parallel search: like many independent spotlights

Visual Search

• Serial search: each item is selected until target is found

Visual Search

• Serial search: each item is selected until target is found

Visual Search

• Serial search: each item is selected until target is found

Visual Search

• Serial search: each item is selected until target is found

Visual Search

• How could you test which kind of search was happening?

Visual Search

• Search Slope: How long per item?

Visual Search

• Search Slope: How long per item?

Visual Search

• Search Slope: How long per item?

Visual Search

• Parallel search - search time is independent of distracter number

Search Slope

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Distractors

Response Time (ms)

Visual Search

• Search slope for color singletons is flat. What does this tell us about color and attention?

Visual Search

• Search slope for shape singletons is flat. What does this tell us about shape and attention?

Visual Search

• Conjunction search: NOT FLAT!

Visual Search

• Serial Search - linear increase in search time with number of distractors

Search Slope

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Visual Search

• Search Slopes can be flat for targets defined by:– color– orientation– curvature– motion– depth

• What does this imply about these features ?

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• Article by Anne Treisman