Control of Attention
• Major Distinctions:
Voluntary
Overt
or
or
Reflexive
Covert
Studying Attention
• Posner Cue-Target Paradigm
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:
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
People tend to be faster and more
accurate on validly cued trials !
Pardigms Used To Study
Attention
• Does the Posner Cue - Target Paradigm
elicited voluntary or reflexive orienting?
Pardigms Used To Study
Attention
• Does the Posner Cue - Target Paradigm
elicited voluntary or reflexive orienting?
Either or both! It depends on how it is set up.
Voluntary Orienting
• What are some ways to make sure that
subjects are voluntarily orienting attention?
– use informative cue (validity greater than 50%)
– use a symbolic cue
Voluntary Orienting
• Symbolic vs. Stimulus Cues
Symbolic
Stimulus
+
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? ~ 200 - 400 ms
Invalid
Response
Time
Valid
Cue - Target Interval
It takes a few hundred ms to gain
full benefit of attention
• Even non-informative cues cause faster
responses when they are valid…why?
Reflexive Orienting
• Even non-informative cues cause faster
responses when they are valid…why?
• 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
Transients
• We call this reflexive orienting or
attentional capture
Reflexive Orienting
• Stimulus cues sometimes confound
reflexive and voluntary orienting
Reflexive Orienting
• Stimulus cues sometimes confound
reflexive and voluntary orienting
• How could we change the Posner cueing
paradigm to make it assess only reflexive
orienting?
Reflexive Orienting
• Stimulus cues sometimes confound
reflexive and voluntary orienting
• How could we change the Posner cueing
paradigm to make it assess only reflexive
orienting?
• Make validity 50% (non-informative cue)
Reflexive Orienting
• Time course of reflexive orienting is
counterintuitive
Response
Time
Valid
Invalid
0
500
1000
Cue - Target Interval (ms)
Reflexive Orienting
• Time course of reflexive orienting is
counterintuitive
• Delayed response at validly cued location after
long cue-target interval is known as Inhibition of
Return
Reflexive Orienting
• Time course of reflexive orienting is
counterintuitive
• Delayed response at validly cued location after
long cue-target interval is known as Inhibition of
Return
• 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
• Potential cues for Reflexive Orienting
– Loud noise
– Motion
– New Object
Transients
• New Objects are powerful attention
grabbers!
Reflexive Orienting
• New objects capture attention
New Objects Capture Attention
IS THERE AN “H”?
Yantis & Jonides (1990): New-Object Paradigm
Initial scene
viewed for
several
hundred ms
New Objects Capture Attention
IS THERE AN “H”?
New scene:
search for
target letter
Yantis & Jonides (1990): New-Object Paradigm
Reflexive Orienting
• Steven Yantis and colleagues
– Result:
Reflexive Orienting
• Steven Yantis and colleagues
– Result:
Targets are found faster when they are
“new objects” than when they are
revealed from “old” objects
Reflexive Orienting
• Steven Yantis and colleagues
– Interpretation:
The visual system prioritizes in dealing
with visual objects - relatively recent
objects are “flagged” while older objects
are disregarded
Parallel vs. Serial Information
Processing
• Remember - attention is about information
processing
Parallel vs. Serial Information
Processing
• Remember - attention is about information
processing
• A fundamental question was “how much
information can be processed at once?”
Parallel vs. Serial Information
Processing
• Remember - attention is about information
processing
• A fundamental question was “how much
information can be processed at once?”
– The answer seemed to be “not much” - but can
we get a better understanding ?
Parallel vs. Serial Information
Processing
• Remember - attention is about information
processing
• A fundamental question was “how much
information can be processed at once?”
– The answer seemed to be “not much” - but can
we get a better understanding ?
• At issue is whether or not the brain can
processes several items at once or must
selectively attend to each item in turn
Parallel vs. Serial Information
Processing
• How could you determine that ?
Next Time
• How could you determine that ?
How to determine that.
(Read Treisman Article for Friday)