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• Read article by Anne Treisman
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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Distractors
Response Time (ms)
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