take your test today by 5!. shadowing many early studies employed variations on a paradigm called...
TRANSCRIPT
Take your test today by 5!
Shadowing
• Many early studies employed variations on a paradigm called “shadowing”
“Four score and seven years ago…”
“It was the best of times, it was the worst of times…”
“Four score and seven years ago…”
Stages of Selection• The other possibility is Late Selection
Stages of Selection
• Testing Early Selection Theory - what prediction can be made?
Stages of Selection
• Testing Early Selection Theory - what prediction can be made?
• Information (such as words) in unattended channel shouldn’t be processed for meaning
Stages of Selection
• Testing Early Selection Theory - what prediction can be made?
• Information (such as words) in unattended channel shouldn’t be processed for meaning
• Demonstrates that Early Selection Theory is not entirely correct
Stages of Selection
• Testing Early Selection Theory - what prediction can be made?
Stages of Selection
• Testing Early Selection Theory - what prediction can be made?
• Should be able to find differences in brain activity in primary sensory areas (A1, V1)
Stages of Selection
• Electrical activity recorded at scalp (EEG) shows differences between attended and unattended stimuli in A1 within 90 ms
Hansen & Hillyard (1980)
Stages of Selection
• Evidence exists for both early and late selection mechanisms
– One interpretation: early reduction in “sensory gain” followed by late suppression of unselected information
Orienting Attention
Control of Attention
• Major Distinctions:
Voluntary Reflexive
Control of Attention
• Major Distinctions:
Voluntary Reflexive
Overt Covert
Voluntary Orienting
• shifting attention by willfully selecting a location in space (or a frequency of sound)
Eye movements (overt orienting)
Voluntary Orienting
• Attention can be oriented covertly – a commonly used metaphor is “the spotlight of
attention”
Paradigms Used To Study Attention
• Posner Cue - Target Paradigm:
VALID CUE TRIAL
Paradigms Used To Study Attention
• Posner Cue - Target Paradigm:
VALID CUE TRIAL
Paradigms Used To Study Attention
• Posner Cue - Target Paradigm:
VALID CUE TRIAL
Paradigms Used To Study Attention
• Posner Cue - Target Paradigm:
X
VALID CUE TRIAL
Paradigms Used To Study Attention
• Posner Cue - Target Paradigm:
Subject presses a button as soon as x appears - dependent variable is response time (RT)
VALID CUE TRIAL
Paradigms Used To Study Attention
• Posner Cue - Target Paradigm:
INVALID CUE TRIAL
Paradigms Used To Study Attention
• Posner Cue - Target Paradigm:
INVALID CUE TRIAL
Paradigms Used To Study Attention
• Posner Cue - Target Paradigm:
INVALID CUE TRIAL
Paradigms Used To Study Attention
• Posner Cue - Target Paradigm:
X
INVALID CUE TRIAL
Paradigms Used To Study Attention
• Posner Cue - Target Paradigm:
Attention Effect = Valid RT - Invalid RT
Voluntary Orienting
• Under what circumstances would a cue lead to a voluntary shift of attention?
Voluntary Orienting
• Under what circumstances would a cue lead to a voluntary shift of attention?– Informative cue– Validity = greater than 50%
Voluntary Orienting
• Under what circumstances would a cue lead to a voluntary shift of attention?– Informative cue– Validity = greater than 50%
• What is another way to make this paradigm a voluntary orienting paradigm?
Voluntary Orienting
• What is another way to make this paradigm a voluntary orienting paradigm?
Symbolic cues orient attention towards another location.Stimulus cues orient attention to the stimulated location.
Voluntary Orienting
• What is the time course of voluntary orienting?
Cue - Target Interval
ResponseTime
Invalid
Valid
Reflexive Orienting
• Attention can be automatically “summoned” to a location at which an important event has occurred:
•
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
• The Posner cueing paradigm confounds reflexive and voluntary orienting
Reflexive Orienting
• The Posner cueing paradigm confounds reflexive and voluntary orienting
• How could we change the Posner cueing paradigm to make it asses only reflexive orienting?
Reflexive Orienting
• The Posner cueing paradigm confounds reflexive and voluntary orienting
• How could we change the Posner cueing paradigm to make it asses only reflexive orienting?
• Make validity 50% (non-informative cue)
Reflexive Orienting
• Time course of reflexive orienting is counterintuitive
Cue - Target Interval (ms)
ResponseTime
Valid
Invalid
0 500 1000
Reflexive Orienting
• Time course of reflexive orienting is counterintuitive
• Delayed response at validly cued location after long cue-target interval is known as IOR
Reflexive Orienting
• Time course of reflexive orienting is counterintuitive
• Delayed response at validly cued location after long cue-target interval is known as IOR
• Thought to occur because attention goes to cued location, then leaves and is inhibited from returning
Reflexive Orienting
• Can symbolic cues be reflexive?
Reflexive Orienting
• Can symbolic cues be reflexive?
Reflexive orienting to direction of eye gaze
Reflexive Orienting
• New objects capture attention