3. I. Classic Approaches
A. Dichotic Listening – present auditory
information via stereo headphones,
participants shadowed (e.g. repeated)
the information from one ear
5. I. Classic Approaches
A. Dichotic Listening – present auditory
information via stereo headphones,
participants shadowed (e.g. repeated)
the information from one ear
1. Participants could report minimal information
about the unattended message
2. Sex of the speaker and speech vs. Noise
3. Led to filter theories of attention
6. I. Classic Approaches
B. The Cocktail Party Effect
- subjects can recognize
their own name in the
unattended channel
(Moray, 1959)
7. II. Sustained Attention
A. Vigilance Tasks
B. Signal Detection Analysis
C. Applications of Sustained Attention
8. II. Sustained Attention
A. Vigilance – refers to a person’s ability to attend to an
area in which a stimulus may appear of long periods of
time.
9. II. Sustained Attention
B. Signal Detection
1. Signal-Detection Theory (SDT) – concerns
our ability to detect the presence of a
“signal”
a. “Signal” can be a sound, light, letter in a group of
distracter letters, tumor in an x-ray
b. Four possible outcomes…
11. II. Sustained Attention
B. Signal Detection
1. Signal-Detection Theory (SDT) – concerns
our ability to detect the presence of a
“signal”
a. “Signal” can be a sound, light, letter in a group of
distracter letters, tumor in an x-ray
b. Four possible outcomes…
c. Performance is determined by how difficult it is to
detect a stimulus and the observer’s bias
(criterion) - e.g. their willingness to make a false
alarm vs. a miss
12. II. Sustained Attention
B. Signal Detection
c. Performance is determined by how difficult it is to
detect a stimulus and the observer’s bias – e.g.
their willingness to make a false alarm vs. a miss
d. A liberal observer will make more false alarms,
but have fewer misses
e. A conservative observer will have fewer false
alarms, but more misses
f. Examples
13. II. Sustained Attention
C. Applications of Sustained Attention
1. Air traffic control, military radar operator, plant
operator, airport screening
2. Studies demonstrate reduced hit rates over time (e.g.
increased misses) – due to changes in bias (criterion)
3. Training and technology can assist in overcoming this
change in bias
4. In one study, we found abstinent smokers were more
likely to miss a target during a vigilance task
5. In other research, we found a negative relationship
between androgens and vigilance performance
14. III. Selective Attention
A. Selective Attention refers to the ability to
focus attention on a specific object,
location, message or other stimulus
B. Requires an allocation of attentional
resources
1. We have limited cognitive resources to
allocate to tasks
2. Cognitive load is the amount of resources
required to carry out a task
3. Automatic tasks use fewer resources
15. III. Selective Attention
C. Examples of Selective Attention Tasks
1. Dichotic listening
2. Flanker Task
3. Stroop Task
16. Flanker Task
Participants instructed to press the ‘z’key
when A or B are the center letter or ‘m’
when C or D and ignore the ‘flankers’
Compatible Trial B A B
Incompatible C A C
Neutral X A X
17. Stroop Task
GREEN RED BLUE
BLUE ORANGE YELLOW
RED BLUE GREEN
ORANGE GREEN RED
YELLOW BLUE ORANGE
RED YELLOW BLUE
GREEN RED YELLOW
YELLOW GREEN ORANGE
18. IV. Visual Attention
A. Spatial Orienting
1. Posner Cueing paradigm
2. Evidence that the ignored locations are
inhibited
B. Object Orienting
19. IV. Visual Attention
A. Spatial Orienting
1. Posner Cueing paradigm
2. Evidence that the ignored locations are inhibited
3. Location based attention part of the where pathway
B. Object Orienting
1. A distinct system for directing attention to objects
2. The object orienting system is part of the what
pathway
20. V. Feature Integration Theory
A. Visual Search – refers to scanning the
environment for particular features
1. Performance will depend on the target and
background (e.g. distracters)
2. Examples
21.
22.
23.
24. V. Feature Integration Theory
A. Visual Search – refers to scanning the
environment for particular features
1. Performance will depend on the target and
background (e.g. distracters)
2. Examples
3. A feature search occurs when only a single
feature is required to detect the target
25. V. Feature Integration Theory
A. Visual Search
3. A feature search
occurs when only
a single feature is
required to detect
the target – aka
“pop-out”
26. V. Feature Integration Theory
A. Visual Search
3. A feature search
occurs when only a
single feature is
required to detect the
target – aka “pop-
out”
4. A conjunction search
is required when two
features must be
used in conjunction
to detect the target
27. V. Feature Integration Theory
A. Visual Search
3. A feature search occurs when only a
single feature is required to detect the
target – aka “pop-out”
4. A conjunction search is required when
two features must be used in conjunction
to detect the target
B. Feature-Integration Theory – explains
the ease of feature searches compared
to conjunction searches
28. V. Feature Integration Theory
B. Feature-Integration Theory – explains the ease
of feature searches compared to conjunction
searches
1. Each feature associated with a “mental
map” across the visual field
2. For every stimulus, the features are
represented immediately, simultaneously
and pre-attentively
3. During a feature search, we monitor the
relevant map for the presence of the
feature
4. This can be done in parallel (all at once)
5. Thus feature searches are independent of
the size of the display
29. V. Feature Integration Theory
B. Feature-Integration Theory
3. During a feature search, we monitor the
relevant map for the presence of the
feature
4. This can be done in parallel (all at once)
5. Thus feature searches are independent of
the size of the display
6. In a conjunction search, for each object
the features must be bound together
7. Use our attentional resources to
accomplish feature binding
8. Conjunction searches are therefore
carried out sequentially – one object at a
time
30. VI. Attention and Visual
Perception
A. Inattentional Blindness
1. Neisser – the girl with the umbrella
2. Paying attention to one aspect of a visual scene
makes one ‘blind’ to the other aspects of the
scene
B. Change-Blindness
31. VI. Attention and Visual
Perception
C. Inhibitory Accounts of Visual Attention
1. Attention is directed to objects, locations or
different aspects of a stimulus (Stroop)
2. The ignored stimuli are actively inhibited
3. This is shown by increased RTs
4. Evidence
• Negative priming – Tipper (1985)
• Spatial Orienting – Posner et al (1980)
• Stroop Effect
32. VII. Divided Attention – Capacity
Theories
A. Aim – to explain how we can perform
more than one task at a time, e.g. dual-
task performance
B. View
1. General, limited pool of resources
2. The amount of cognitive resources required
by a task depends on how complex the task
is (task complexity)
33. VII. Divided Attention – Capacity
Theories
B. View
1. General, limited pool of resources
2. The amount of cognitive resources required
by a task depends on how complex the task
is (task complexity)
3. Allocation of Resources – when the pool of
resources is insufficient, must allocate
resources – some tasks may suffer
34. VII. Divided Attention – Capacity
Theories
B. View
3. Allocation of Resources – when the pool of
resources is insufficient, must allocate
resources – some tasks may suffer
4. Allocation Policy – how do we allocate?
• Enduring dispositions – “built-in” stimuli that will
always capture our attention
• Momentary intentions – situational dispositions to
allocate resources depending on the situation
35. VII. Divided Attention – Capacity
Theories
B. View
4. Allocation Policy – how do we allocate?
• Enduring dispositions – “built-in” stimuli that will
always capture our attention
• Momentary intentions – situational dispositions to
allocate resources depending on the situation
C. Predictions
1. Can attend to more than one thing so long
as resources not exceeded
36. C. Divided Attention – Capacity
Theories
C. Predictions
1. Can attend to more than one thing so long
as resources not exceeded
2. Performance on one task will decline if the
resource pool is exceeded
3. The system is flexible
D. Automaticity is key – well practiced tasks
require fewer resources
37. VIII. Applications of Attention
Remember, attention
like all cognitive
processes has limits
Any additional tasks
take away resources
from other tasks
Cell phones and
driving
38. VIII. Applications of Attention
Remember, attention
like all cognitive
processes has limits
Any additional tasks
take away resources
from other tasks
Cell phones and
driving
Heads-up displays –
inhibitory accounts…
