Department of Psychology Department of Psychology Institute for Simulation and Training Institute for Simulation and TrainingUniversity of Central FloridaUniversity of Central Florida

Orlando, FL 32826Orlando, FL 32826

Vigilance and Vigilance and Sustained AttentionSustained Attention

P.A. Hancock

Presentation for the Class of 2008

Human Factors II EXP 6257

January 31st, 2008

Norman MackworthNorman Mackworth

Mackworth was the founder of modern vigilance research, a term he took from the neurologist, Sir Henry Head. Hisoriginal experimental research was triggered by WW II concerns for radaroperators looking for submarines outover the Bay of Biscay. His original monograph on the topic, republishedin Sinako’s text, still represents the best introduction to the area.

Mackworth was the first to formally identified the ‘vigilance decrement function’ which remains pertinent to all operations in automated and semi-automated 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 DecrementThe Vigilance Decrement

Theories of Vigilance

Inhibition theory (behaviorism)

Expectancy Theory

Arousal Theory

Resource Theory

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 information-processing 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.

Raja Parasuraman

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

ModalitySignal 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

0

10

20

30

40

50

60

70

80

90

100

1 2 3 4Periods of Watch (10-min)

Per

cent

Cor

rect

Det

ecti

ons

Auditory

Visual

Psychophysics of Vigilance: Event Rate

Psychophysics of Vigilance: Signal Salience

Psychophysics of Vigilance: Signal Duration

90

80

0

10

20

30

40

50

60

70

100

Periods of Watch (10-min)

Ove

rall

Wor

kloa

d

Card sorting task

1 2 3 4

AuditoryVisual

Overall Workload as a Function of Periods of Watch

Periods of Watch (10 min)

Wei

ghte

d F

rust

rati

on R

atin

g

0

50

100

150

200

250

WFR = 87.9 + 35.9PW

1 2 3 4

Weighted Frustration as a Function of Periods of Watch

Workload and PerformanceEvent Rate

Time Modality Task Type

Source Complexity

Perf - - A>VSIM >SUC

or SIM<SUC

-

WL + +/0 A=V T x C/0 +

Note. A= Auditory Task; V= Visual TaskSIM = Simultaneous Task; SUC = Successive TaskT x C = interaction between task type and display complexity

Workload and Performance

SignalSalience

P(S) KR/cueingSpatial

uncertaintyTemporal

Uncertainty

Perf + + +/0(KR) - -

WL - ? -/0(both) + ?

Task-Based Stress and Performance

Event Rate

Time Modality Task Type

Source Complexity

Perf - - A>VSIM >SUC

or SIM<SUC

-

Perceived Stress

0 + A < V SUC>SIM? ?

Note. A= Auditory Task; V= Visual TaskSIM = Simultaneous Task; SUC = Successive TaskT x C = interaction between task type and display complexity

Task-Based Stress and Performance

SignalSalience

P(S) KR/cueingSpatial

uncertaintyTemporal

Uncertainty

Perf + + +/0(KR) - -

Perceived Stress

- ?- (KR)

0 ?(cueing)? ?

DSSQ

Task EngagementEnergetic Arousal

MotivationConcentration

WorrySelf-focused Attention

Self-EsteemTask-related Cognitive Interference

Task-irrelevant Cognitive Interference

DistressTense ArousalHedonic Tone

Confidence & Control

-2

-1.5

-1

-0.5

0

0.5

1

1.5

2

Sta

ndar

d S

core

EA Motivation Concen.

Task Engagement

TA HT C&C S-Focus S-Esteem CI-TR CI-TI

Distress Worry

Pre-vigilPost-vigil

Pre- and Post-Vigil Scores for the DSSQ Scales

-2

-1.5

-1

-0.5

0

0.5

1

1.5

2

1 2 3 4

Periods of Watch (10-min)

Stan

dard

Sco

re

Energetic Arousal Motivation Concentration

1 2 3 4 1 2 3 4

VisualAuditory

Periods of Watch (10-min) Periods of Watch (10-min)

-2

-1.5

-1

-0.5

0

0.5

1

1.5

2

1 2 3 4

Stan

dard

Sco

re

Tense Arousal Hedonic Tone Confidence & Control

1 2 3 4 1 2 3 4

Periods of Watch (10-min) Periods of Watch (10-min) Periods of Watch (10-min)

-2

-1.5

-1

-0.5

0

0.5

1

1.5

2

1 2 3 4

Stan

dard

Sco

re

Self-Focused Attention Self-Esteem CI-TR

1 2 3 4 1 2 3 4 1 2 3 4

CI-TI

Periods of Watch (10-min) Periods of Watch (10-min) Periods of Watch (10-min) Periods of Watch (10-min)

Task Engagement

Distress

Worry

Configural Displays and Vigilance

Input 1 Input 2Output Input 1 Input 2OutputInput 1 Input 2Output Input 1 Input 2Output

Configural Bar Graph Display

Integration TaskFocused Attention Task

Neutral Event Critical Signal Neutral Event Critical Signal

Configural Displays and Vigilance

Input 1 Input 2OutputInput 1 Input 2Output Input 1 Input 2OutputInput 1 Input 2Output

Non-Configural Bar Graph Display

Integration TaskFocused Attention Task

Neutral Event Critical Signal Neutral Event Critical Signal

Configural Displays and Vigilance

Input 1 Input 2OutputInput 1 Input 2Output

Object Configural Display

Input 1 Input 2Output Input 1 Input 2Output

Integration TaskFocused Attention Task

Neutral Event Critical Signal Neutral Event Critical Signal

Sensitivity as a function of periods of Watch for the integration task

0.8

0.82

0.84

0.86

0.88

0.9

0.92

0.94

0.96

0.98

1

1 2 3 4

Periods of Watch (6-min)

A'

conint

nonint

objinit

Sensitivity as a function of periods of Watch for the focused attention task

0.8

0.82

0.84

0.86

0.88

0.9

0.92

0.94

0.96

0.98

1

1 2 3 4

Periods of Watch (6-min)

A'

conf

nonf

objf

Response Bias as a function of periods of Watch for the integration task

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

1 2 3 4

Periods of Watch (6-min)

Res

po

nse

Bia

s

conint

nonint

objinit

Response Bias as a function of periods of Watch for the focused attention task

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

1 2 3 4

Periods of Watch (6-min)

Res

po

nse

Bia

s

conf

nonf

objf

0

10

20

30

40

50

60

70

80

group

Ov

eral

l Wo

rklo

ad

Non-ConfiguralDisplay

ConfiguralDisplay

Object Configural Display

Overall Workload as a Function of Display Type

Overall pre-post vigil changes as a function of DSSQ scale

-2

-1.5

-1

-0.5

0

0.5

1

1.5

2

Z-s

co

re

EA TA HT S-MOT I-MOT CONC SF SE CC CITR CITI

DSSQ Scale