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

3. Orienting Attention Posner Cue - Target Paradigm:

4. Orienting Attention Posner Cue - Target Paradigm:

5. Orienting Attention Posner Cue - Target Paradigm:

6. Orienting Attention Posner Cue - Target Paradigm: X

7. Orienting Attention Posner Cue - Target Paradigm:

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

9. Orienting Attention Posner Cue - Target Paradigm:

10. Orienting Attention Posner Cue - Target Paradigm:

11. Orienting Attention Posner Cue - Target Paradigm:

12. Orienting Attention Posner Cue - Target Paradigm: X

13. Orienting Attention Posner Cue - Target Paradigm:

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

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

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

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

18. 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?

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

20. Voluntary Orienting What is the time course of voluntary orienting? Cue - Target Interval Response Time Invalidly Cued Targets Validly Cued Targets About 200 ms

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

22. 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

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

24. 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?

25. 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)

26. Reflexive Orienting Time course of reflexive orienting is counterintuitive Cue - Target Interval (ms) Response Time Valid Invalid 0 5001000 About 50 ms

27. 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 (IOR)

28. 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 (IOR) Thought to occur because attention goes to cued location, then leaves and is inhibited from returning

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

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

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

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

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

34. Reflexive Orienting Steven Yantis and colleagues –Result:

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

36. 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

37. The Physiology of Attention

38. Physiology of Attention Neural systems involved in orienting Neural correlates of selection

39. Disorders of Orienting Lesions to parietal cortex can produce some strange behavioural consequences Parietal Lobe

40. Disorders of Orienting Lesions to parietal cortex can produce some strange behavioural consequences –patients fail to notice events on the contralesional side –Patients behave as if they are blind in the contralesional hemifield but they are not blind

41. Disorders of Orienting Lesions to parietal cortex can produce some strange behavioural consequences –patients fail to notice events on the contralesional side –Patients behave as if they are blind in the contralesional hemifield but they are not blind

42. Disorders of Orienting Called Hemispatial Neglect - patients appear unable to process information in the contralesional hemifield

43. Disorders of Orienting Hypothesis: Parietal cortex somehow involved in orienting attention into contralesional space

44. Disorders of Orienting Posner and colleagues –Use cue-target paradigm to investigate attentional abilities of parietal lesion patients ContralesionalIpsilesional

45. Disorders of Orienting Results: Valid cue in contralesional field is effective invalid- contralesional target valid - contralesional target invalid - ispilesional target valid - ipsilesional target Results: Severe difficulty with invalidly cued contralesional target

46. Disorders of Orienting Interpretation: –Patients have difficulty disengaging attention from good hemifield so that it can be shifted to contralesional hemifield

47. Disorders of Orienting Interpretation: –Patients have difficulty disengaging attention from good hemifield so that it can be shifted to contralesional hemifield –Parietal cortex is somehow involved in disengaging attention

48. Disorders of Orienting Disengage - Shift - Engage Model –Parietal Cortex notices events and disengages attention

49. Disorders of Orienting Disengage - Shift - Engage Model –Parietal Cortex notices events and disengages attention –Superior Colliculus moves attention

50. Disorders of Orienting Disengage - Shift - Engage Model –Parietal Cortex notices events and disengages attention –Superior Colliculus moves attention –Pulvinar Nucleus reengages attention

51. Disorders of Orienting Disengage - Shift - Engage Model –Parietal Cortex notices events and disengages attention –Superior Colliculus moves attention –Pulvinar Nucleus reengages attention –Entire process is under some top-down control from Frontal Cortex

52. Disorders of Orienting Orienting mechanism can be interfered with in normal brains

53. Disorders of Orienting Orienting mechanism can be interfered with in normal brains –changes that are not accompanied by transients are hard to detect

54. Disorders of Orienting Orienting mechanism can be interfered with in normal brains –changes that are not accompanied by transients are hard to detect e.g. building appearing slowly orienting mechanism scans the scene aimlessly

55. Disorders of Orienting Orienting mechanism can be interfered with in normal brains –changes that are not accompanied by transients are hard to detect e.g. building appearing slowly orienting mechanism scans the scene aimlessly –changes accompanied by full-field transients are hard to detect e.g. change blindness orienting mechanism is blinded by the transient