1. An introduction to attention
Peter König

2. What is attention
Everyone knows what attention is. It is the taking possession of the mind, in clear and vivid form, of one out of what seem several simultaneous possible objects or trains of thought. Focalization, concentration of consciousness are of its essence. It implies withdrawal from some things in order to deal effectively with others, and is a condition which has a real opposite in the confused, dazed, scatterbrain state….
– William James (1890)

3. Overt attention
Movements of the eyes allow selective aquisition of visual signals.
Other sensory organs equally allow selective capturing of environmental signals.

4. Selection of signals by sensors

5. How are salient points selected?
The concept of a saliency map
“Where is the action?”
Bottom-up approach
But … !

6. Spotlight of attention
• Helmholtz observed that we can enhance perception, if we focus our attention on a location in the visual field.
• However, enhancing perception in one part of the visual field takes place at the expense of other areas.

7. The shadowing task I
Condition 1: 65% correct
Condition 2: 20% correct

8. Shadowing task II
Somewhere Among hidden the in most the spectacular Rocky Mountains cognitive near abilities Central City is Colorado the an ability old to miner select hid one a message box from of another. Gold. We Although do several this hundred by people focusing have our looked attention for on it, certain they cues have such not as found type it style.

9. Covert attention

10. A physiological substrate I

11. Attentional systems

12. Plaza Milano

13. Broadbend‘s filter theory
Early selection.
Selection is based on physical properties of the stimulus (e.g., pitch, loudness, etc...).
Only one input channel can be processed at a time.
Semantic interpretation only after selection.
Conscious control.
It takes time to shift attention.

14. Late selection Attended Channel: THE GIRL WAS dogs, six, beach ...
Unattended Channel: world, eight, WAITING FOR HER ...
Reported: THE GIRL WAS WAITING FOR HER ...

15. Popout
Popout as pre-attentive processing. The more popout, the later selection!?
Can be trained!

16. Stroop task
red
yellow
blue
green

17. But!?

18. Effects in early visual cortex

19. Effects of attention

20. Competing hypothesis
• early selection - Broadbent (1958) proposed that physical characteristics of messages are used to select one message for further processing and all others are lost
• attenuation - Treisman (1964) proposed that physical characteristics are used to select one message for full processing and other mes- sages are given partial processing
• late selection - Deutsch & Deutsch (1963) proposed that all messages get through, but that only one response can be made (late selection).

21. The temporal domain V4

22. Applications?!

23. What did we learn / the next time
Overt/covert attention
When: Early, middle, late …
What: Spatial … Object oriented attention
Where: Areas, -band … Single neurons, Clinical syndromes
How: Saliency maps … Top-down models
Suggested readings: Kastner, Annual Review neurosciences, 2000; JR Anderson, Chapter 3

24. A definition by exclusion
Awake
Asleep
Inattentiveness
(drowsy, relaxed)
Different
sleep stages
Alert
Ignore
Attend

25. Popout Popout as pre-attentive processing.
The more popout, the later selection.
T among I and Y vs. T among I and Z.
Can be trained!

27. Covert attention

28. Treisman’s attenuation theory

29. What did we learn? Types of attention What can we attend to
Overt attention, covert attention
What can we attend to
Spatial attention, object based attention
- Physical characteristics, semantic contents
Properties of attention
Mechanisms of attention
Why attention

30. What do we want to know? Types of attention What can we attend to
Properties of attention
Mechanisms of attention
Why attention

31. Selection by processing stages

32. Parallel and serial search

33. Central peripheral cues

34. Early or late?
Treisman and Geffen (1967) set about to test whether the filter was early or late in the processing stream. They had subjects shadow a message on one ear, and tap whenever they heard a certain word in either ear. When the key word appeared in the attended ear, subjects tapped 87% of the time, but when the key word appeared in the unattended ear, subjects tapped 8% of the time. This indicates that early selection is occurring.

35. Conjunction search

36. Lesions

37. Monkey cortex

38. What can we attend to? Spatially oriented attention vs.
Object oriented attention
Popout as a pre-attentive mechanism

39. Change blindness

40. Selective and divided attention
Attention is studied by presenting participants with two or more stimuli at the same time.
This is called dual-task performance.
In selective (focused) attention tasks, people are instructed to respond to one input only.
In divided attention tasks, people are asked to process and respond to more than one input.

41. Divided attention
Tracking task. Can track several targets simultaneously.

42. Dilation in space and time
Expanding dot demo.

43. Physiological mechanisms
Partiel lobe lesions
Balint‘s syndrome
Attention is a gateway to consciousness.

44. Covert attention, cortex

45. Details of parallel search

46. Problems with spotlight

47. Spotlight or zoom-lens

48. Object centered attention

49. Scaling tuning curves

50. Neuroscience <-> Psychology
what do these examples tell us about the relation between mental phenomena and physical states of the brain?
* unrelated ? complete independence -- too many corresponding phenomena
* irrelevant ? somehow related, but without any serious implications -- unlikely, because it is possible to influence percepts by affecting neurons (TMS)
* correlated ? not independent, but possibly not more than common result from unknown cause -- possible from the above, but perhaps not enough?
* causal ? neuronal state determines mental state -- likely in some instances, but applicable to all mental events? is consciousness emerging from neural activity?
if we would reach a complete understanding of all brain mechanisms, from the single molecule to the function of extended neural networks, would we be able to comprehensively predict mental states? A. Snyder (Centre for the Mind): Yes

51. Yet another definition
Attention - Attention is what enables us to process information about the world around us. We can only be aware of things around us if we pay attention to them. We can think of attention as a spotlight that we shine on things in the world around us to make them stand out. When something "stands out," we notice it, bringing it into our awareness, and then process or interpret it. Attention can change rapidly, switching from one thing to another. It can be steered by our intentions ("top-down"), as when we look for a particular face in a crowd, or it can be steered by features of objects in the world ("bottom-up"), as when our attention is grabbed by a police car's flashing lights in our rearview mirror. Preattentive processes help us decide what to pay attention to and what to filter out and ignore. Attention filters and feeds information about the world around us into our minds