4. Attention
The Legend of Bagger Vance (2000)
Matt Damon, Will Smith, Charlize Theron
“Finding the Field” https://www.youtube.com/watch?v=s-SpyM6lVvs
5. Introduction
“Everybody knows what attention is. It is the taking
possession of the mind, in clear and vivid form, of
one out of what seem several simultaneously possible
objects or trains of thought. Focalisation,
concentration, of consciousness are of its essence.[…] It
implies withdrawal from some things in order to deal
effectively with others […]” (William James in
“Principles of Psychology”, 1890)
6. Introduction
“Everybody knows what attention is. It is the taking
possession of the mind, in clear and vivid form, of
one out of what seem several simultaneously possible
objects or trains of thought. Focalisation,
concentration, of consciousness are of its essence.[…] It
implies withdrawal from some things in order to deal
effectively with others […]” (William James in
“Principles of Psychology”, 1890)
7. Introduction
Definition
Attention is the cognitive process of selectively concentrating on
one aspect of the external or internal environment while ignoring
other aspects.
Experimental research on attention started in the 1950s
8. Introduction
Attention in Perception
If we look around us we experience an amazing richness of
detail.
But we do not notice the detail of objects unless attention is
directed to them.
Demonstration: Close your eyes
What’s the colour of my shirt?
What’s the colour of your friend’s shirt/jumper
On your mobile phone, what’s the bottom right item?
9. Introduction
Change blindness
„Flicker paradigm“ (Rensinck et al., 1997)
See http://www2.psych.ubc.ca/~rensink/flicker/download/index.html
https://www.youtube.com/watch?v=bh_9XFzbWV8
Even big changes to a picture take a while to notice
10. Introduction
Change blindness – Flicker paradigm
Explanation
The „bottom-up“ perceptual processing is optimised towards continuous
input.
In continuous input, changes are easily detected (usually changes are due to
motion). Motion is highly salient and pulls our attention towards it.
The brief blank screen between the two pictures disrupt the basic bottom-up
processing. No continuous motion can be detected.
Changes have to be searched for by deliberate attentional „top-down“
control, searching location by location…
11. Introduction
Change blindness
Is it relevant for real life?
Could you swap the conversation partner?
„The Door Study“, see:
http://youtu.be/FWSxSQsspiQ
12. Introduction
The influence of attention on perception
has implications
Eye witness testimony
Witnesses may miss changes in the identity of
the suspect.
Driving a car in traffic
Elderly are slower in change detection
Human Machine Interaction
Missing of important signals
E.g. radar operators
15. Models of Attention
Attention allows us to focus on a particular stimulus while at the
same time disregarding other stimuli.
Key research questions
Which stimuli do we attend to?
At which level of processing do we decide what to attend to?
What happens to the stimuli that are not attended?
16. Models of Attention
Cocktail Party Phenomenon
In a party, you have no problem concentrating on your
conversation despite all other conversations
You also have little difficulty switching your focus from one
conversation to another
17. Models of Attention
Cherry (1953) wanted to investigate the Cocktail Party
phenomenon scientifically
Dichotic listening paradigm
A different message is played to each ear.
When voices had the same physical properties, participants
could not separate the messages using meaning only.
Message 2
Message 1
18. Models of Attention
How much is retained from the unattended message?
Shadowing task
A different message is played to each ear.
Overtly repeat message played to one ear.
- Overt repetition requires
strong focusing of attention
on the attended input.
- Consequently, no attention
on the ignored input.
- Was anything of the ignored
remembered or recognized?
19. Models of Attention
How much is retained from the unattended message?
Mostly physical properties (e.g. tonality) were noticed
Virtually no noticing of
Meaning of the message
Change in language (English to German)
Change in gender (male to female)
Message in reverse speech
It seems that unattended messages are filtered very early in the
sensory processing, because virtually no „higher-level“
information is retained.
21. Models of Attention
Filter model (Broadbent, 1958)
Which channel is attended to?
E.g. Vision, Audition, …?
Guided by attention (voluntarily, goal-directed, top-down)
May also be guided by reflexive attention, i.e. a salient stimulus
automatically captures attention (involuntary, bottom-up)
22. Models of Attention
Brief detour: The concept of „Salience“ (or „saliency“)
Definition: The state or quality by which an item (e.g. object or
person) stands out relative to its neighbours.
Salience typically arises from the contrasts between items and their
neighbourhood.
23. Models of Attention
Brief detour: The concept of „Salience“ (or „saliency“)
Examples
A A A A A A A
A A A A A A A
A A A A A A A
A A A A A A A
A A A A A A A
A A A A A A A
Salience by color. Note that the same color (e.g. red) can
result in a stimulus being salient (left) or not salient
(right) – depending on the contrast (i.e. difference) to its
neighbours.
24. Models of Attention
Filter model (Broadbent, 1958)
Which channel is attended to?
Guided either top-down or bottom-up
Which information is attended to?
Which conversation do we follow?
To which point in our view do we look?
Guided bottom-up by basic physical features (e.g. pitch,
loudness, colour, direction,…)
25. Models of Attention
Filter model (Broadbent, 1958)
The stimuli passing the filter become the focus of attention
The unattended stimuli are completely disregarded
It is an „all-or-nothing“ filter
26. Models of Attention
… last week I
went golfing
with Edward,
and … Edward is in conversation
with Betty.
Then John drops Edwards
name.
It is very likely that
Edward will notice this
and will orient his
attention towards John‘s
conversation.
The early-selection filter model by
Broadbent cannot account for this finding.
Me:
27. Models of Attention
Attenuator model (Treisman, 1964)
Is based on Broadbent‘s filter model
Different mechanism for filtering:
Not by an all-or-nothing filter (Broadbent)
But by a gradual working „attenuator“
Anne Treisman (with her husband,
Daniel Kahneman, Psychologist
and 2002 Nobel Prize Winner)
28. Models of Attention
When is an attenuated message
analysed?
• When its activation exceeds a
threshold.
• Threshold affected by: Context and
priming; Subjective importance;
Degree of Attenuation
29. Models of Attention
Attenuator model (Treisman, 1964)
Is an Early-Selection model (like Broadbent‘s model).
Allows for initially unattended information to become attended
(and, thus, aware).
All other information is decaying in early sensory memory.
Unattended information can have no effect on behaviour.
Behaviour is only affected by information we become aware of,
i.e. by attended information.
30. Models of Attention
Late-selection models (Deutsch & Deutsch, 1963; Norman 1968)
All information is fully analysed for meaning.
Then, based on physical properties and meaning, selection by a
filter takes place.
Evaluation
Advantage: Since all information is processed, it is unlikely that
important information is missed.
Disadvantage: Very resource demanding.
31. Models of Attention
Late-selection model
Broadbent‘s filter model
(Early selection)
Treisman‘s attenuator
model (Early selection)
Late selection model
32. Models of Attention
James Vicary (1957)
subliminal = below threshold of perception
https://www.youtube.com/watch?v=X_5E43ZZ5k8
With respect to the attention models
What type of information needs to be processed for this?
Attended or unattended?
Which model would support this?
33. Models of Attention
James Vicary (1957):
• Presented subliminal messages in a movie for 0.3 ms (every 5 s)
• He reported that sales of Coke increased by 18%, of Popcorn by 58%
• However, these results were faked
• Subliminal persuasion by other means does sometimes work
Bargh & Chartrand (1999) The unbearable automaticity of being
34. Models of Attention
Key assumption of late-selection models: All information is fully
processed.
Including information which is unattended and unaware.
Thus, unattended and unaware information should have the
power to influence behaviour
(which is impossible according to all early-selection models)
Did Vicary disprove late-selection models?
35. Models of Attention
A proper scientific test
Subliminal priming (Dehaene et al., 1998)
Target
Prime
Mask 2
Mask 1
A – Alphanumeric (“6”)
V – Verbal (“SIX”)
The masks make
the prime
invisible.
The prime is
unaware
information.
Nevertheless, the prime
affects response times, i.e.
behavior.
The fact that the prime
affects behaviour
irrespective of notation
shows:
• It is no perceptual
priming.
• Its semantic meaning
has been processed.
36. Models of Attention
Subliminal priming works well
Many variations have confirmed subliminal priming
James Vicary’s “Coca Cola”-ads did not work
What is the difference?
In subliminal priming paradigms (like Dehaene’s)
participants prepared themselves to respond as quickly as possible to a
number, and the prime was a number as well.
the influenced behaviour (i.e., the response) occurred very soon (< 1 s) after
the prime.
37. Models of Attention
Subliminal priming
What is the difference?
If the prime does not relate to the current behavioural goals, it is
ineffective.
Drink Coke
Left
In these examples, there would most likely be no effect on behaviour at all.
38. Models of Attention
There is evidence for early selection models
Information of unattended channels is not really retained
There is evidence for late selection models
Subliminal stimuli are processed for their meaning
??????
39. Models of Attention
Which model is correct?
Maybe both?
Maybe sometimes selection is early, and sometimes late?
But what determines whether selection is early or late?
40. Models of Attention
Theory of perceptual load (Lavie; 1995, 2000)
„load theory“
Difficult tasks
E.g., find a specific DVD among other DVDs
Require a lot of attentional resources
Selection is early to make resources available
Easy tasks
E.g., find a DVD among books
Require only little attentional resources
Selection is late since resources are available
Nilli Lavie
UCL London
41. Models of Attention
Two choice response
task. Target letters:
• “x” – left finger
• “z” – right finger
Distractor letters:
• “X”, “Z”, or any other
letter.
• Task irrelevant. Is to
be ignored.
Low load:
• Only one potential
target letter.
• Easy task.
High load:
• Find target letter
among 5 other letters.
• Difficult task.
(Easy task)
(Difficult task)
(Late selection)
(Early selection)
Distractor is processed
(and, thus, disctracts)
only in the easy task.
42. Models of Attention – Summary
Early selection model (Broadbent, 1958)
Unattended information is filtered out completely early in
processing
Attenuator model (Treisman, 1964)
Unattended information is attenuated early in
processing
Late-selection model (Deutsch & Deutsch, 1963)
All information is processed, it is filtered out only late in
processing
Theory of perceptual load (Lavie, 1995)
Selection is early in difficult task, and late in easy tasks
45. Automaticity
The Great Escape (1963)
Steve McQueen, James Garner, Richard Attenborough
https://www.youtube.com/watch?v=o0wNl66tT3Q
46. Automaticity
Controlled Automatic
Requires attention Does not require attention
Limited capacity Unlimited capacity
Rather slow Rather fast
Effortful Effortless
Is aware, conscious Outside awareness
Controllable Uncontrollable
Flexible Inflexible
Some theories classify processing strictly as either controlled or automatic,
while other theories regard it as a gradual transition between the two.
49. Automaticity
How does an activity become automatic?
Practice!
But how?
Schneider & Shiffrin (1977)
Controlled and automatic processing is based on the same
cognitive processes
Practice results in an increase in efficiency of these processes
50. Automaticity
Logan‘s (1988) instance theory of automaticity
Practice results in a shift of strategy of how a task is performed
Controlled and automatic processing is based on different cognitive processes
Unpracticed: General algorithm used to solve problems
(controlled process)
Practiced: Memory retrieval of past solutions (automatic process)
51. Automaticity
Logan‘s (1988) instance theory of automaticity
Example: Multiplication 5 x 4
Initially: Sum the „5“ four times (5+5 = 10; +5 = 15; +5 = 20). This is
slow and effortful – a controlled process.
After practice, we have learned that 5 x 4 = 20. When we
encounter this problem, we can simply retrieve this solution from
memory. This is fast and effortless – an automatic process.
52. Automaticity
Dangers of Automaticity
Tourists in the UK are in danger of
missing cars because they look in
the wrong direction.
“Highway hypnosis”: People drive
without any awareness.
53. Automaticity – Summary
Automatic processing is effortless, fast, and outside of awareness.
Thus, automaticity greatly reduces demands on cognitive control and
attention
Suppose you would need to explicitly attend to every action, like
walking, driving, drinking/eating, writing,…
The most profound disadvantage of automatic processes is their
inflexibility.
Automaticity can be established by practice.
