1. Chapter 4
Attention

2. Some Questions to Consider
Is it possible to focus attention on just one thing, even when lots of other things are going on at the same time?
Under what conditions can we pay attention to more than one thing at a time?
What does attention research tell us about the effect of talking on cell phones while driving a car?
Is it true that we are not paying attention to a large fraction of the things happening in our environment?

3. Attention
Process of concentrating on specific features of the environment or on certain thoughts or activities
Selective: excluding of other features of the environment
Limited: in capacity and timing
Both overt and covert: we can consciously attend to information but some information grabs our attention

4. Selective Attention
Ability to focus on one message and ignore all others
We do not attend to a large fraction of the information in the environment
Filtering out some information and promoting other information for further processing

5. Research Method: Dichotic Listening
One message is presented to the left ear and another to the right ear
Participant “shadows” one message to ensure he is attending to that message
Can we completely filter out the message to the unattended ear and attend only to the shadowed message?

6. Caption: In the shadowing procedure, a person repeats out loud words he has just heard.

7. Results of Dichotic Listening
Participants could not report the content of the message in unattended ear
Knew that there was a message
Knew the gender of the speaker
However unattended ear is being processed at some level
Cocktail party effect
Change in gender is noticed
Change to a tone is noticed

8. Models of Selective Attention
Models of Selective Attention
Where does the attention filter occur?
Early in processing
Later in processing
Early selection model
Broadbent’s filter model
Intermediate selection model
Tresiman’s attenuation theory
Late selection model
e.g. McKay (1973)

9. Broadbent’s Filter Model
Early-selection model
Filters message before incoming information is analyzed for meaning
Caption: Flow diagram of Broadbent’s filter model of attention.

10. Broadbent’s Filter Model
Sensory memory
Holds all incoming information for a fraction of a second
Transfers all information to next stage

11. Broadbent’s Filter Model
Identifies attended message based on physical characteristics
Only attended message is passed on to the next stage
Detector
Processes all information to determine higher-level characteristics of the message

12. Broadbent’s Filter Model
Short-term memory
Receives output of detector
Holds information for seconds and may transfer it to long-term memory

13. Broadbent’s Model Could Not Explain
Broadbent’s Model Could Not Explain
Participant’s name gets through
Cocktail party phenomenon
Participants can shadow meaningful messages that switch from one ear to another
Dear Aunt Jane (Gray & Weddeburn, 1960)
Effects of practice on detecting information in unattended ear
You can be trained to detect in unattended ear
Based on the meaning of the message

14. Tresiman’s Attenuation Theory
Intermediate-selection model
Attended message can be separated from unattended message early in the information-processing system
Selection can also occur later
Caption: Flow diagram for Treisman’s attenuation model of selective attention.

15. Treisman’s Attenuation Theory
Attenuator
Analyzes incoming message in terms of physical characteristics, language, and meaning
Attended to message is let through the attenuator at full strength
Unattended message is let through at a much weaker strength

16. Treisman’s Attenuation Theory
Dictionary unit
Contains words, each of which have thresholds for being activated
Words that are common or important have low thresholds
Uncommon words have high thresholds

17. Caption: The dictionary unit of Treisman’s model contains words, each of which has a threshold for being detected. This graph shows the thresholds that might exist for three words. The person’s name has a low threshold, so it will be easily detected. The thresholds for the words rutabaga and boat are higher, because they are used less or are less important to this particular listener.

18. Late Selection Models
Selection of stimuli for final processing does not occur until after information has been analyzed for meaning

19. Late Selection Models McKay (1973)
In attending ear, participants heard ambiguous sentences
“They were throwing stones at the bank.”
In unattended ear, participants heard either
“river”
“money”

20. Late Selection Models McKay (1973)
In test, participants had to choose which was closest to the meaning of attended to message:
They threw stones toward the side of the river yesterday
They threw stones at the savings and loan association yesterday

21. Late Selection Models McKay (1973)
The meaning of the biasing word affected participants’ choice
Participants were unaware of the presentation of the biasing words

22. Task Load and Selective Attention?
Task load: how much of a person’s cognitive resources are used to accomplish a task
High-load: uses almost all; no resources for other tasks
Low-load: uses few; resources for other tasks

23. Caption: Flanker-compatibility task
Caption: Flanker-compatibility task. (a) Display in which the small square is the target, and the large square on the right is the distractor. This distractor is “compatible” because it is the same as the target. (b) Display in which the distractor is “incompatible” because it is different from the target. (c) Results of Green and Bevelier’s (2003) experiment, which found that the reaction time to indicate the presence of a target is longer for the incompatible distractor (bar I) than for the compatible distractor (bar C).

24. Flanker-Compatibility Task
Can participants focus their attention on detecting the target so that the identity of the distractor will not affect their performance?

25. Flanker-Compatibility Task
Low-load condition: one potential target
Reaction time is longer for incompatible distractors
Participant still had resources available to process additional information

26. Caption: Stimuli for the flanker-compatibility task in which the load is increased by adding additional stimuli to the display. The target is still the square, as in figure 4.10, so the distractor is compatible in (a) and incompatible in (b). The results, shown in (c), indicate that under this high-load condition, the reaction times are the same for both compatible and incompatible distractors. (From Green & Bevelier, 2003).

27. Flanker-Compatibility Task
High-load condition: type of distractor does not affect reaction time
Participants use all resources
No resources to process the distractor

28. Low load: experts’ performance is similar to non-experts
Video-Game Experts
Low load: experts’ performance is similar to non-experts
High load: experts still had enough resources left to process distractors
Performance transferable to flanker-compatibility task

29. Effect of Load on Selective Attention
High-load experiments support early selection
Low-load experiments support late selection

30. Divided Attention
Practice enables people to simultaneously do two things that were difficult at first
Spelke et al. (1976)
After hours of practice, participants could read and categorize dictated words

31. Schneider and Shiffrin (1977)
Divided Attention
Schneider and Shiffrin (1977)
Divide attention between remembering target and monitoring rapidly presented stimuli
Memory set: 1-4 target characters
Test frames: could contain random dot patterns, a target, distractors

32. Caption: Consistent mapping condition for Schneider and Shiffrin’s (1977) experiment.

33. Caption: Improvement in performance with practice in Schneider and Schiffrin’s (1977) experiment. The arrow indicates the point at which participants reported that the task had become automatic. This is the result of experiments in which there were four target stimuli in the memory set and two stimuli in each frame.

34. Divided Attention
Consistent mapping condition: target would be numbers, and distractors would be letters
Over time, participants became able to divide their attention
Automatic processing occurs without intention and only uses some of a person’s cognitive resources

35. Divided Attention Stroop effect
Name of the word interferes with the ability to name the ink color
Cannot avoid paying attention to the meanings of the words

36. Caption: Varied mapping condition for Schneider and Shiffrin’s (1977) experiment. This is more difficult than the consistent mapping condition because all the characters are letters and also because a character that was a distractor on one trial (like the T) can become a target on another trial, and a character that was in the memory set on one trial (like the P) can become a distractor on another trial.

37. Schneider and Shiffrin (1977)
Divided Attention
Schneider and Shiffrin (1977)
Varied mapping condition: rules changed from trial to trail
Over time, participants never achieved automatic processing

38. Divided Attention
Controlled processing: participants paid close attention, and their search was slow and controlled

39. Caption: Comparing performance on the consistent and varied mapping tasks. Note that the horizontal axis indicates the duration of each target frame. These graphs show that frames must be presented for longer durations to achieve good performance in the varied mapping condition.

40. 100-car naturalistic driving study
Divided Attention
100-car naturalistic driving study
Video recorders placed in cars
Risk of accident is four times higher when using a cell phone

41. Strayer and Johnston (2001)
Divided Attention
Strayer and Johnston (2001)
Simulated driving task
Participants on cell phone missed twice as many red lights and took longer to apply the brakes
Same result using “hands-free” cell phone

42. Attention and Visual Perception
Inattentional blindness: a stimulus that is not attended is not perceived, even though a person might be looking directly at it

43. Caption: Inattentional blindness experiment
Caption: Inattentional blindness experiment. (a) On each trial, participants judge whether the horizontal or vertical arm is longer. (b) After a few trials, the inattention trial occurs, in which a geometric object is flashed along with the arms. (c) In the recognition test, the participant is asked to indicate which geometric object was presented.

44. Attention and Visual Perception
Change blindness: if shown two versions of a picture, differences between them are not immediately apparent
Task to identify differences requires concentrated attention and search

45. Caption: Frames from the video shown in the Levin and Simons’ (1997) experiment. Note that the woman on the right is wearing a scarf around her neck in shots A, C, and D, but not in shot B. Also, the color of the plates changes from red in the first three frames to white in frame D, and the hand position of the woman on the left changes between shots C and D.

46. Eye movements, attention, and perception
Overt Attention
Eye movements, attention, and perception
Saccades: rapid movements of the eyes from one place to another
Fixations: short pauses on points of interest
Studied by using an eye tracker

47. Bottom-up Determinants of Eye Movement
Stimulus salience: areas that stand out and capture attention
Bottom-up process
Depends on characteristics of the stimulus
Color and motion are highly salient

48. Top-Down Determinants of Eye Movements
Scene schema: knowledge about what is contained in typical scenes
Help guide fixations from one area of a scene to another
Eyes movements are determined by task
Eyes movements preceded motor actions by a fraction of a second

49. Caption: Sequence of fixations of a person making a peanut butter sandwich. The first fixation is on the loaf of bread.

50. Covert Attention: Attention without Eye Movements
Precueing: directing attention without moving the eyes
Participants respond faster to a light at an expected location than at an unexpected location
Even when eyes kept fixed

51. Caption: Procedure for (a) valid trials and (b) invalid trials in Posner et al.’s (1978) precueing experiment; (c) the results of the experiment. The average reaction time was 245 ms for valid trials but 305 ms for invalid trials.

52. Object-Based Visual Attention
Location-based: moving attention from one place to another
Object-based: attention being directed to one place on an object

53. Object-Based Visual Attention
Egly et al. (1994)
Participants saw two side-by-side rectangles, followed by a target cue
Reaction time fastest when target appeared where indicated
Reaction time was faster when the target appeared in the same rectangle

54. Object-Based Visual Attention
The enhancing effect of attention spreads throughout the object
Attention can be based on the
Environment
static scenes or scenes with few objects
Specific object
dynamic events

55. Caption: Steps in Treisman’s feature integration theory
Caption: Steps in Treisman’s feature integration theory. Objects are analyzed into their features in the preattentive stage, and then the features are combined later with the aid of attention.

56. Feature Integration Theory (FIT)
Preattentive stage
Automatic
No effort or attention
Unaware of process
Object analyzed into features

57. Feature Integration Theory (FIT)
Treisman and Schmidt (1982)
Participants report combination of features from different stimuli
Illusory conjunctions occur because features are “free floating”

58. Caption: Stimuli for illusory conjunction

59. Feature Integration Theory (FIT)
Focused attention stage
Attention plays key role
Features are combined

60. Feature Integration Theory (FIT)
Treisman and Schmidt (1982)
Ignore black numbers and focus on objects
Participants can correctly pair shapes and colors

61. Feature Integration Theory (FIT)
R.M.: Patient with Balint’s syndrome
Inability to focus attention on individual objects
High number of illusory conjunctions reported

62. Feature Integration Theory (FIT)
Mostly bottom-up processing
Top-down processing influences processing when participants are told what they would see
Top-down processing combines with feature analysis to help one perceive things accurately

63. Physiology of Attention
Attention enhances neural responding
Attentional processing is distributed across a large number of areas in the brain

64. Physiology of Covert Attention
Monkey trained to fixate eyes on a dot while a peripheral light was flashed
Fixation only: monkey was to release bar when the fixation light dimmed
Fixation and attention: monkey was to release bar when peripheral dimmed

65. Caption: Top: Stimuli for Colby et al
Caption: Top: Stimuli for Colby et al.’s (1995) selective attention experiment. The monkey always looked at the fixation light. A peripheral stimulus light was flashed inside the circle on the right. Below: (a) Nerve firing when the monkey was looking at the fixation light but was not paying attention to the peripheral light; (b) firing when the monkey was looking at the fixation light and paying attention to the peripheral stimulus light.

66. Physiology of Covert Attention
Single cell recordings showed monkey’s response when paying attention to the peripheral light was not caused by changes of the stimulus on the retina but by the monkey’s attention to light

67. Attention Processing Distributed Across the Cortex
Using fMRI to detect cortical activity during a search task
Attention to an expected direction of motion caused brain activity to increase in a number of brain areas

68. Caption: The results of Schulman and coworkers’ (1999) experiment, showing some of the brain areas activated by viewing the moving dots. The graphs indicate the amount of brain activity when participants were cued to pay attention to a particular direction of movement (red lines) and when they were cued to just passively view the moving dots (green lines).

69. Attention in Social Situations: Autism
Autism: serious developmental disorder in which one of the major symptoms is the withdrawal of contact from other people

70. Attention in Social Situations: Autism
Can solve reasoning problems that involve social situations
Cannot function when placed in an actual social situation
This may be due to the way those with autism observe what is happening

71. Attention in Social Situations: Autism
Non-autistic observers look to eyes to assess emotional reaction
Autistic observers look to the mouth or off to the side of the face to assess emotional reaction

72. Attention in Social Situations: Autism
Autistic people’s attention (or lack thereof) may be one way in which they see things differently in the environment