Control of Attention

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

2. Studying Attention • Posner Cue-Target Paradigm

3. Paradigms Used To Study Attention • Posner Cue - Target Paradigm: VALID CUE TRIAL

4. Paradigms Used To Study Attention • Posner Cue - Target Paradigm: VALID CUE TRIAL

5. Paradigms Used To Study Attention • Posner Cue - Target Paradigm: VALID CUE TRIAL

6. Paradigms Used To Study Attention • Posner Cue - Target Paradigm: X VALID CUE TRIAL

7. Paradigms Used To Study Attention • Posner Cue - Target Paradigm: INVALID CUE TRIAL

8. Paradigms Used To Study Attention • Posner Cue - Target Paradigm: INVALID CUE TRIAL

9. Paradigms Used To Study Attention • Posner Cue - Target Paradigm: INVALID CUE TRIAL

10. Paradigms Used To Study Attention • Posner Cue - Target Paradigm: X INVALID CUE TRIAL

11. 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 !

12. Pardigms Used To Study Attention • Does the Posner Cue - Target Paradigm elicited voluntary or reflexive orienting?

13. 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.

14. 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

15. Voluntary Orienting • Symbolic vs. Stimulus Cues Symbolic + Stimulus Symbolic cues orient attention towards another location. Stimulus cues orient attention to the stimulated location.

16. 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

17. Even non-informative cues cause faster responses when they are valid…why?

18. 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:

19. 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 reflexive orienting or attentional capture Transients

20. Reflexive Orienting • Stimulus cues sometimes confound reflexive and voluntary orienting

21. 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?

22. 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)

23. Reflexive Orienting • Time course of reflexive orienting is counterintuitive Response Time Valid Invalid 0 500 1000 Cue - Target Interval (ms)

24. 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

25. 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

26. Reflexive Orienting • Can symbolic cues be reflexive?

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

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

29. Reflexive Orienting • New objects capture attention

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

31. New Objects Capture Attention IS THERE AN “H”? New scene: search for target letter Yantis & Jonides (1990): New-Object Paradigm

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

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

34. 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

35. Parallel vs. Serial Information Processing • Remember - attention is about information processing

36. Parallel vs. Serial Information Processing • Remember - attention is about information processing • A fundamental question was “how much information can be processed at once?”

37. 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 ?

38. 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

39. Parallel vs. Serial Information Processing • How could you determine that ?

40. Next Time • How could you determine that ? How to determine that. (Read Treisman Article for Friday)