Vigilance and
Sustained Attention
P.A. Hancock
Presentation for the Class of 2008
Human Factors II EXP 6257
January 31st, 2008
Department of Psychology s Institute for Simulation and Training
University of Central Florida
Orlando, FL 32826
Mackworth was the founder of modern
vigilance research, a term he took from
the neurologist, Sir Henry Head. His
original experimental research was
triggered by WW II concerns for radar
operators looking for submarines out
over the Bay of Biscay. His original
monograph on the topic, republished
in Sinako’s text, still represents the
best introduction to the area.
Norman Mackworth
Mackworth was the first to formally
identified the ‘vigilance decrement
function’ which remains pertinent to
all operations in automated and semiautomated systems today. His work on
stress effects was also pivotal. He
worked at the APU Cambridge for part
of his career, as did many other
influential scientists who have had a
fundamental impact on applied human
performance theory. Others include
Broadbent, Poulton, Baddeley,
Wilkinson, etc.
The Vigilance Decrement
Theories of Vigilance
Inhibition theory (behaviorism)
Expectancy Theory
Arousal Theory
Resource Theory
Raja Parasuraman
Raja Parasuraman has long-standing
research programs in two areas, human
factors and cognitive neuroscience. The
first concerns human performance in
human-machine systems, particularly
with respect to the influence of
automation and computer technology on
attention, memory, and vigilance. His
second area of research is the cognitive
neuroscience of attention, where he has
conducted studies using informationprocessing paradigms, event-related brain
potentials and functional brain imaging
(PET, fMRI), both in normal populations
and in relation to aging and Alzheimer’s
disease. He also has a research thrust in
the molecular genetics of cognition,
specifically attention and working
memory. Finally, he has recently
combined his interests in human factors
(ergonomics) and cognitive neuroscience
by developing the field of
neuroergonomics, which he defines as the
study of brain and behavior at work.
The Vigilance Taxonomy
Task Type: Simultaneous vs. Successive
Modality: Visual vs. Auditory
Source Complexity: Single vs. Multiple
Event Rate: Slow vs. Fast
Psychophysics of Vigilance
First Order Factors:
Immediate physical properties of the stimulus
Modality
Signal Salience (Conspicuity)
Event Rate
Second Order Factors:
Characteristics of the stimulus inferred by the
observer based on experience with the task
Signal Uncertainty (Spatial & Temporal)
Psychophysics of Vigilance: Modality
100
Percent Correct Detections
90
80
70
60
50
Auditory
Visual
40
30
20
10
0
1
2
3
Periods of Watch (10-min)
4
Psychophysics of Vigilance: Event Rate
Psychophysics of Vigilance:
Signal Salience
Psychophysics of Vigilance:
Signal Duration
Overall Workload as a Function of Periods of Watch
100
90
Auditory
Visual
Overall Workload
80
70
60
50
40
30
20
Card sorting task
10
0
1
2
3
Periods of Watch (10-min)
4
Weighted Frustration Rating
Weighted Frustration as a Function of Periods of Watch
250
200
150
100
WFR = 87.9 + 35.9PW
50
0
1
2
3
Periods of Watch (10 min)
4
Workload and Performance
Event
Rate
Time
Modality
Task
Type
Source
Complexity
-
+
Perf
-
-
A>V
SIM >SUC
or
SIM<SUC
WL
+
+/0
A=V
T x C/0
Note. A= Auditory Task; V= Visual Task
SIM = Simultaneous Task; SUC = Successive Task
T x C = interaction between task type and display complexity
Workload and Performance
Signal
Salience
KR/cueing
Spatial
uncertainty
Temporal
Uncertainty
P(S)
Perf
+
+
+/0(KR)
-
-
WL
-
?
-/0(both)
+
?
Task-Based Stress and Performance
Event
Rate
Time
Modality
Task
Type
Source
Complexity
-
?
Perf
-
-
A>V
SIM >SUC
or
SIM<SUC
Perceived
Stress
0
+
A<V
SUC>SIM
?
Note. A= Auditory Task; V= Visual Task
SIM = Simultaneous Task; SUC = Successive Task
T x C = interaction between task type and display complexity
Task-Based Stress and
Performance
Signal
P(S)
Salience
Perf
Perceived
Stress
+
+
KR/cueing
+/0(KR)
Spatial
Temporal
uncertainty Uncertainty
-
-
?
?
- (KR)
-
?
0 ?(cueing)
DSSQ
Task Engagement
Distress
Energetic Arousal
Motivation
Concentration
Tense Arousal
Hedonic Tone
Confidence & Control
Worry
Self-focused Attention
Self-Esteem
Task-related Cognitive Interference
Task-irrelevant Cognitive Interference
Pre- and Post-Vigil Scores for the DSSQ Scales
Task Engagement
Worry
Distress
2
EA Motivation Concen.
1.5
Standard Score
1
0.5
0
-0.5
-1
-1.5
-2
Pre-vigil
Post-vigil
TA
HT
C&C
S-Focus S-Esteem CI-TR CI-TI
Task Engagement
Standard Score
1.5
Concentration
Motivation
Energetic Arousal
2
Auditory
Visual
1
0.5
0
-0.5
-1
-1.5
-2
1
2
3
1
4
2
3
4
1
Periods of Watch (10-min)
Periods of Watch (10-min)
2
3
4
Periods of Watch (10-min)
Distress
Standard Score
Hedonic Tone
Tense Arousal
2
Confidence & Control
1.5
1
0.5
0
-0.5
-1
-1.5
-2
1
2
3
4
1
2
3
4
1
Periods of Watch (10-min)
Periods of Watch (10-min)
2
3
4
Periods of Watch (10-min)
Worry
Self-Focused Attention
Standard Score
2
Self-Esteem
CI-TR
CI-TI
1.5
1
0.5
0
-0.5
-1
-1.5
-2
1
2
3
Periods of Watch (10-min)
4
1
2
3
Periods of Watch (10-min)
4
1
2
3
Periods of Watch (10-min)
4
1
2
3
Periods of Watch (10-min)
4
Configural Displays and Vigilance
Integration Task
Focused Attention Task
Input 1 Output Input 2
Neutral Event
Input 1
Output
Input 2
Input 1
Output
Critical Signal
Configural Bar Graph Display
Input 2
Neutral Event
Input 1
Output
Critical Signal
Input 2
Configural Displays and Vigilance
Integration Task
Focused Attention Task
Input 1
Output
Neutral Event
Input 2
Input 1
Output
Input 2
Critical Signal
Input 1
Output
Input 2
Neutral Event
Non-Configural Bar Graph Display
Input 1
Output
Input 2
Critical Signal
Configural Displays and Vigilance
Focused Attention Task
Input 1
Output
Neutral Event
Input 2
Input 1
Integration Task
Output
Input 2
Input 1
Critical Signal
Output
Neutral Event
Object Configural Display
Input 2
Input 1
Output
Critical Signal
Input 2
Sensitivity as a function of periods of Watch for the integration task
1
0.98
0.96
0.94
A'
0.92
0.9
conint
0.88
nonint
objinit
0.86
0.84
0.82
0.8
1
2
3
Periods of Watch (6-min)
4
Sensitivity as a function of periods of Watch for the focused attention task
1
0.98
0.96
0.94
A'
0.92
0.9
conf
nonf
0.88
objf
0.86
0.84
0.82
0.8
1
2
3
Periods of Watch (6-min)
4
Response Bias as a function of periods of Watch for the integration task
1
0.9
0.8
Response Bias
0.7
0.6
0.5
conint
0.4
nonint
objinit
0.3
0.2
0.1
0
1
2
3
Periods of Watch (6-min)
4
Response Bias as a function of periods of Watch for the focused attention task
1
0.9
0.8
Response Bias
0.7
0.6
conf
0.5
nonf
objf
0.4
0.3
0.2
0.1
0
1
2
3
Periods of Watch (6-min)
4
Overall Workload as a Function of Display Type
80
70
Overall Workload
60
50
40
30
20
10
0
Non-Configural
Display
Configural
Display
group
Object Configural
Display
Overall pre-post vigil changes as a function of DSSQ scale
2
1.5
Z-score
1
0.5
0
-0.5
-1
-1.5
-2
EA
TA
HT S-MOT I-MOT CONC SF
DSSQ Scale
SE
CC
CITR
CITI