Note on Selective Attention

From

1. Christofer Koch 2013 Lecture Visual Attention and Consciousness
2. Goldstein, Chapter Attention

In nature language Attention refers to a family of abilities

• Vigilance / overall attention
• Selective attention: processing sth in the cost of others
• Distributed attention
  • Automaticity (action / perception task that does not take capacity)

Selective attention is different from general attention —- arousal.

• Has capacity, comes with a cost. It’s selective!

Note: Tracking eye / pupil size can help judge the attention level!

• Very large effect! Can be used to judge attention base on few trials.

Phenomenal Models

Resources allocation model

• Several Components
  • Arousal ~ Attention Capacity
  • Allocation Policy
    • What decides where gets attention: Spatial / Feature / Temporal
  • Possible Allocation targets

Filter Model: Early Filter/Attenuator/ Late Filter

Experiment: Dual channel sentence input -> attend to one of them

• Un-attended message / signal is attenuated / filter out at early stage!
• But stimulus saliency / system’s default gain also matters
  • “Your own name” and some alert message is very salient!!
• However, some information can get through, masking channel can get attended to if it’s salient enough

Feature Integration Theory

Model

• Visual system analyze the images into features (Pre-attentive stage)
• Then featues get integrated binded into objects.
• Binding depends on
  • Saliency, Guidance, Attention!

Visual Search Task:

• Single feature search: search time invariant to object number
• Multi feature conjunction search: Scale linearly to object number
• But saliency, subtelity of difference affects the speed!

Selective Attention

• Bottom Up Attention “Catch your eye ball”
  • Sometimes called Saliency!
  • There is good algorithm to calculate / simulate saliency
    • Even commercialized! Really important for Advertisement and Printing industry.
• Top Down Attention : Flexible and task dependent
  • Spatial based attention;
  • Feature based attention: Very interesting phenomenon
  • Object form based attention
    • Strong effect! Even when object cued is moving, there is still cuing based facilitation.
    • NOTE: OBJECT based attention can be used to CHECK what the subject judge as one WHOLE OBJECT!
    • Kanisza Rectangle…

Experiment: Posner’s task

• Visual Cueing: Cue is used to manipulate attention!

• Exognenous Cue
  • Fast (SOA for effect)
  • Coming from saliency of the object
  • ~ Superior Colliculus
• Endogenous Cue
  • Slow (SOA for effect)
  • Depending on interpretation, can learn and adapt depending on the predictability!

Brain Substrate

Related Brain Regions (in primates): Seems attention and eye movement is closely related!

• FEF (Frontal Eye Field), LIP (Lateral Infero Parietal), V4, SC (Superior Colliculus), Pulvinar

Remark:

• Eye movement vs Selective attention ~ Overt attention vs Covert attention

Neural effects of Attention

• In V1, attention increases the Gain and/or Baseline firing rate in a retinotopy measure
  • Effect in Bias towards detection.
  • (2009). I know where you are secretly attending! The topography of human visual attention revealed with fMRI. Vision Research

When Attention Fails

Attention Related Error (a.k.a. Inattentional Blindness)

• Inattentional Blindness [Invisible ]
• Discontinuity Error: Simons and Levin 1998
  • When we attend to something, we ignore some major change in the figure!!
  • By some minor features we identify the object/ person is the same person and begin to do something else! But they are not the same person.
  • We can catch the “Gist” / “theme” quite easily, but specific visual features many cases elude our attention
• Application
  • For Driving: It’s the attention loss that most detrimental to calling / texting during driving!
  • Attention manipulation is the core trick for all magicians.
  • Can be used by Movie directors and Visual Effects Artists.

Consciousness