1 / 46

Stages of Selection

Stages of Selection. Broadbent: Early Selection - a bottleneck exists early in the course of sensory processing that filters out all but the attended channel

yamka
Download Presentation

Stages of Selection

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Stages of Selection • Broadbent: Early Selection - a bottleneck exists early in the course of sensory processing that filters out all but the attended channel • Alternative theory: Late Selection - the bottleneck exists not at the lowest stages, but at the highest - such as response planning, memory and consciousness

  2. Stages of Selection

  3. Stages of Selection • Testing Early Selection Theory - what prediction can be made?

  4. Stages of Selection • Testing Early Selection Theory - what prediction can be made? • Information (such as meaning of words) in unattended channel shouldn’t be processed for meaning

  5. Stages of Selection • Shadowing Task: ignore one input, repeat back the other • Subjects are largely unaware of unshadowed message but… • Certain words such as their name distract them!? • Why is this puzzling?

  6. Stages of Selection • Testing Early Selection Theory - what is another prediction that can be made? • Should be able to find differences in brain activity in primary sensory areas (A1, V1)

  7. Stages of Selection • Electrical activity recorded at scalp (EEG) shows differences between attended and unattended stimuli in A1 within 90 ms Hansen & Hillyard (1980)

  8. 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

  9. Orienting Attention

  10. Control of Attention • Major Distinctions: Voluntary Reflexive

  11. Control of Attention • Major Distinctions: Voluntary Reflexive Covert Overt

  12. Voluntary Orienting • Attention can be oriented covertly • a commonly used metaphor is “the spotlight of attention”

  13. Orienting Attention • Posner Cue - Target Paradigm: Subject presses a button as soon as x appears

  14. Orienting Attention • Posner Cue - Target Paradigm:

  15. Orienting Attention • Posner Cue - Target Paradigm:

  16. Orienting Attention • Posner Cue - Target Paradigm:

  17. Orienting Attention • Posner Cue - Target Paradigm: X

  18. Orienting Attention • Posner Cue - Target Paradigm:

  19. Orienting Attention • Posner Cue - Target Paradigm: That was a validly cued trial because the x appeared in the box that flashed

  20. Orienting Attention • Posner Cue - Target Paradigm:

  21. Orienting Attention • Posner Cue - Target Paradigm:

  22. Orienting Attention • Posner Cue - Target Paradigm:

  23. Orienting Attention • Posner Cue - Target Paradigm: X

  24. Orienting Attention • Posner Cue - Target Paradigm:

  25. Orienting Attention • Posner Cue - Target Paradigm: That was an invalidly cued trial because the x appeared in the box that didn’t flash

  26. Paradigms Used To Study Attention • Posner Cue - Target Paradigm: Attention Effect = Valid RT - Invalid RT

  27. Voluntary Orienting • Under what circumstances would a cue lead to a voluntary shift of attention?

  28. Voluntary Orienting • Under what circumstances would a cue lead to a voluntary shift of attention? • Informative cue • Validity = greater than 50%

  29. 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?

  30. Voluntary Orienting • What is another way to make this paradigm a voluntary orienting paradigm? Symbolic Cue Symbolic cues may orient attention towards another location. Stimulus cues orient attention to the stimulated location.

  31. Reflexive Orienting • Attention can be automatically “summoned” to a location at which an important event has occurred:

  32. 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

  33. Reflexive Orienting • The Posner cueing paradigm (with blinking boxes) confounds reflexive and voluntary orienting … in what way?

  34. Reflexive Orienting • The Posner cueing paradigm (with blinking boxes) confounds reflexive and voluntary orienting • How could we change the Posner cueing paradigm to make it asses only reflexive orienting?

  35. Reflexive Orienting • The Posner cueing paradigm (with blinking boxes) 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)

  36. Reflexive Orienting • The Posner cueing paradigm (with blinking boxes) 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) • Viewers are still faster and more accurate!

  37. Reflexive Orienting • Can symbolic cues be reflexive? Almost never but …

  38. Reflexive Orienting • Can symbolic cues be reflexive? Reflexive orienting to direction of eye gaze

  39. Reflexive Orienting • Potential cues for Reflexive Orienting • Loud noise • Motion • New Object • New Objects are powerful attention grabbers! Transients

  40. New Objects Capture Attention IS THERE AN “H”? Initial scene viewed for several hundred ms Yantis & Jonides (1990): New-Object Paradigm

  41. New Objects Capture Attention IS THERE AN “H”? New scene: search for target letter H may be revealed from an 8 or may appear as a new object Yantis & Jonides (1990): New-Object Paradigm

  42. Reflexive Orienting • Steven Yantis and colleagues • Result:

  43. Reflexive Orienting • Steven Yantis and colleagues • Result: Targets are found faster when they are “new objects” than when they are revealed from “old” objects

  44. 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

  45. Attention and Consciousness • The attention orienting mechanism can be confused leading to something called “change blindness”

  46. Attention and Consciousness

More Related