LIMITED – Allocate attention, switch among tasks;
SELECTIVE– Direct search
– Evaluate what is not currently in attention
Properties of Attention
Today. . .limited
• What can we say about how attention is allocated?
• What mechanisms do you use to protect the limited resource of attention?
• How do you solve the problem that attention is limited?
Allocation
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Sperling & Melchner: Arrays flash by one at a time, 240ms each: subjects are to name the location and identification of the two digits on each trial
Subjects do better if told whether the digits will be in the inner or outer circle of characters.
Of course not!
What happens that prevents you from allocating attention?
In general we could say that there is distraction from without and distraction from
within.
Allocation: distraction from without
• Sudden, high intensity stimuli in the periphery
• Certain types of stimuli (that aren’t sudden or high intensity) naturally draw attention (examples?)
Demonstration
Ask them “How many windows are in your house or apartment?”
When they answer, note whether they look off into the distance, or keep their gaze on you.
Gatekeeper
Strategy 1: Avoid distracting stimuli. Faces are socially important, & it’s hard not to attend to them.
Strategy 2: Habituate
•With continued exposure, distracting stimuli no longer demand attention.
•This is more effective for stimuli that don’t change much; e.g., harder to habituate to music than a refrigerator hum.
•BUT complexity is not so important
If this painting were behind me as we were having a conversation, you would habituate,
because it’s static.
Strategy 3: admit some stuff, not others
• Next class we’ll talk in more detail about how much the gatekeeper can really evaluate about the stimulus
What is the most distracting auditory stimulus?
Wegner theory
Operating process: seeks mental contents consistent with what you want to think about (no white bear)Monitoring process: searches for mental contents that you are NOT supposed to think about (white bear)—this is a warning system that mental control is about to fail.
Operating process demands attention, but monitoring doesn’t; thus if you’re distracted, or tired, operating can’t work, but monitoring can.
Allocation summary
In order to allocate attention as you desire, you must maintain its focus. Distractions may come from outside (stimuli in environment) or inside (your own thoughts).
The cognitive system has strategies to maintain allocation to the desired targets.
Limited attention: problem 2
Problem 1 was distraction—your desired allocation gets messed up.
Problem 2 is the very fact that attention is limited—you can’t do everything you want to do.
How does your system deal with that problem?
Reduction in demands w/ practice
Automatic
Little or no attentional cost
With or without intention
Not affected by motivation
Can happen w/o awareness
Attentional cost
Occurs only with intention
Affected by motivation
Only with awareness
Controlled
Training to automaticity: Shiffrin & Schneider (1977)
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What effect will # of figures on each card have on errors?
Spelke, Hirst, & Neisser
• Sought automaticity for more complex tasks
• Subjects read stories while they took dictation
• Initially,huge interference
• An hour-long session , 5 days/ week, for six weeks
• Developed automaticity.
LION BEAR TIGER LION
LION LION BEAR BEAR
TIGER BEAR TIGER LION
TIGER LION BEAR TIGER
LION BEAR LION LION
BEAR LION TIGER BEAR
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GREEN RED GREEN RED
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BLUE RED BLUE GREEN
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THE POINT
Reading is automatic and therefore happens without intention: even when you don’t want it to happen, it does.
This phenomenon is limited by context: e.g, stoplight.
cf interference in sports. . .