A Psychophysiological Investigation of the State of Monotony

amongst Air Traffic Controllers

ICRAT 2004, Zilina

Sonja Straussberger, Wolfgang Kallus & Dirk Schäfer

Introduction

Straussberger, S., Kallus, W. & Schäfer, D.

Today’s talk•Relevance of Monotony for Air Traffic Controllers

•The Concept of Monotony

•Results of an Experimental Study

ICRAT 2004, Zilina

Introduction

Monotony in ISO 10075

Straussberger, S., Kallus, W. & Schäfer, D. ICRAT 2004, Zilina

INDIVIDUAL

WORK ENVIRONMENT

Mental Stress

Mental Strain

Activation Warming-up

Mental fatigue

Monotony Reduced vigilance

Mental satiation

Facilitating EffectsImpairing effects

Introduction

What needs to be considered?-Ill-defined and mixed terms

•Monotony (e.g., McBain, 1970)

•Boredom (e.g., Mikulas & Vodanovich, 1993)

•Underload (e.g., Young & Stanton, 2002)

-Contributing factors? •Task Characteristics (e.g. Pfendl, 1985)

•Personality Factors (e.g. Hill, 1975)

•Situational Factors (e.g. Marvje & Horne, 1994)

-Short-term and long-term impairments(e.g., Thackray, 1975; Kass, Vodanovich & Callender, 2001)

Straussberger, S., Kallus, W. & Schäfer, D. ICRAT 2004, Zilina

Introduction

What is a State of Monotony?Bartenwerfer’s concept of Monotony (1960, 1985):

-Specific consequence in situations when continuous engagement in a restricted task is required

-Tasks may be characterized by low stimulation, high repetition, low difficulty level, longer time on Task

-Impacts on physiological, subjective and performance level

Straussberger, S., Kallus, W. & Schäfer, D. ICRAT 2004, Zilina

Introduction

Research Questions

In simulated Air Traffic Control– depending on repetitiveness and dynamic density (DD) in traffic …

…is there a difference in physiological indicators for a state of monotony

…is there a difference in subjective indicators for a state of monotony

in Air Traffic Controllers?

Straussberger, S., Kallus, W. & Schäfer, D. ICRAT 2004, Zilina

Methods

Straussberger, S., Kallus, W. & Schäfer, D.

Experimental Design2 (Break Activity) x 2 (Repetitiveness) x 2 (Sequence of DD) x 2 (Run) x 3 vs. 15 (Interval)-Mixed Design

ICRAT 2004, Zilina

Break Activity

active non active

Repetitiveness Repetitiveness

repetitive non repetitive

repetitive non repetitive

DD DD DD DD DD DD DD DD

Run 1 l h l h l h l h

Run 2 h l h l h l h l

Break

Run 3

n 3 3 3 3 3 3 3 3

n total 24

DD=Sequence of Dynamic Density in Traffic (high (H) - low (L) vs. H (High) – L (Low))

Methods

Operationalization of Repetitiveness & Dynamic Density

Straussberger, S., Kallus, W. & Schäfer, D. ICRAT 2004, Zilina

Methods

Physiological Measures: mean HR, mean HRV in 3-minute-intervals during scenarios

Subjective State : During Scenario: attentiveness, fatigue, boredom, irritation, strain, concentration, motivation, sleepiness (TSI, Thackray et al., 1975; 7-point-rating-scale; ext.)

After Scenario: Mental demand, physical demand, temporal demand, performance, effort, frustration, overall workload (NASA-TLX, Hart & Staveland, 1988) + feeling of monotony, SA Other measures collected

Straussberger, S., Kallus, W. & Schäfer, D.

Dependent Variables

ICRAT 2004, Zilina

Results

Physiological level: heart rate

Straussberger, S., Kallus, W. & Schäfer, D. ICRAT 2004, Zilina

Average corrected HR during first and second run for groups with non repetitive (n=12) and repetitive (n=12) traffic

(Repetitiveness: F1=4.41, p=.05; Run: F1= 17.68, p=.001)

Intervals: Run 1

151413121110987654321

me

an

HR

(co

rr.)

8

6

4

2

0

-2

Repetitiveness

non repetitive

repetitive

Intervals: Run 2

151413121110987654321

me

an

HR

(co

rr.)

8

6

4

2

0

-2

Repetitiveness

non repetitive

repetitive

Results

Physiological level: HRV

Straussberger, S., Kallus, W. & Schäfer, D. ICRAT 2004, Zilina

Average HRV during first and second run for groups with non repetitive (n=12) and

repetitive (n=12) traffic

(Repetitiveness: F1=7.52, p=.013; Run: F1= 24.98, p=.000)

Intervals: Run 1

151413121110987654321

me

an

HR

V

60

50

40

30

20

10

Repetitiveness

non repetitive

repetitive

Intervals: Run 2

151413121110987654321

me

an

HR

V

60

50

40

30

20

10

Repetitiveness

non repetitive

repetitive

Results

Rating: “feeling of monotony”

Straussberger, S., Kallus, W. & Schäfer, D. ICRAT 2004, Zilina

Average ratings for feeling of monotony after first and second run as a function of repetitiveness and sequence of DD

(Run x Repetitiveness: F1=8.83, p=.008; Run x Sequence: F1= 5.39, p=.031; Run x Repetitiveness x Sequence F2=10.57, p=.004)

Runs for DD sequence 'l-h'

21

Ave

rag

e r

atin

gs

for

fee

ling

of

mo

no

ton

y

90

80

70

60

50

40

30

Repetitiveness

non repetitive

repetitive

Runs for DD sequence 'h-l'

21

Ave

rag

e r

atin

gs

for

fee

ling

of

mo

no

ton

y

90

80

70

60

50

40

30

Repetitiveness

non repetitive

repetitive

Results

Rating: “sleepiness”

Straussberger, S., Kallus, W. & Schäfer, D. ICRAT 2004, Zilina

Average change from baseline in perceived sleepiness during first and second run for groups with

non repetitive (n=12) and repetitive (n=12) traffic(Run: F1=14.35, p=.001; Interval: F2=17.80, p=.000;

Run x Sequence: F1=8.44, p=.009; Run x Interval x Repetitiveness: F2=5.83, p=.011)

Intervals: Run 1

321

Ch

an

ge

fro

m B

ase

line

in p

erc

eiv

ed

Sle

ep

ine

ss

2,5

2,0

1,5

1,0

,5

0,0

-,5

-1,0

Repetitiveness

non repetitive

repetitive

Intervals: Run 2

321

Ch

an

ge

fro

m B

ase

line

in p

erc

eiv

ed

Sle

ep

ine

ss

2,5

2,0

1,5

1,0

,5

0,0

-,5

-1,0

Repetitiveness

non repetitive

repetitive

Discussion

Summary & Discussion

-Supports for Theory of Monotony: physiological deactivation

-Self-reports more complex

-Consideration of impairing and facilitating effects

-Implications for work design, work organization and controller selection

Straussberger, S., Kallus, W. & Schäfer, D. ICRAT 2004, Zilina

Thank you for your attention!For further information:

sonja.straussberger@eurocontrol.int

Results

Rating: “boredom”

Straussberger, S., Kallus, W. & Schäfer, D. ICRAT 2004, Zilina

Intervals: Run 1

321

Cha

nge

from

bas

elin

e in

per

ceiv

ed b

ored

om

3,0

2,5

2,0

1,5

1,0

,5

0,0

-,5

Repetitivity

non repetitive

repetitive

Intervals: Run 2

321

Cha

nge

from

bas

elin

e in

per

ceiv

ed b

ored

om

3,0

2,5

2,0

1,5

1,0

,5

0,0

-,5

Repetitivity

non repetitive

repetitive

Average change from baseline in perceived boredom during first and second run for groups with non repetitive (n=12) and

repetitive (n=12) traffic (Repetitiveness: F1=9.24, p=.006; Interval: F2=17.87, p=.000; Run x

Repetitiveness: F1=5.14, p=.035; Interval x Repetitiveness: F2=22.69, p=.000)

Results

Rating: “motivation”

Straussberger, S., Kallus, W. & Schäfer, D. ICRAT 2004, Zilina

Mean ratings of motivation perceived boredom during first and second run for groups with non repetitive (n=12) and repetitive

(n=12) traffic for each Sequence of DD from Run 1 to Run 2 (Run: F1=19.41 p=.000; Interval: F2=12.24, p=.000; Run x Sequence: F1=7.39, p=.013; Run x Repetitiveness x Sequence: F1=5.49, p=.03;)

Runs for DD sequence 'l-h'

21

Me

an

ra

ting

s fo

r m

otiv

atio

n

,4

,2

0,0

-,2

-,4

-,6

-,8

-1,0

-1,2

-1,4

-1,6

Repetitiveness

non repetitive

repetitive

Runs for DD sequence 'h-l'

21

Me

an

ra

ting

s fo

r m

otiv

atio

n

,4

,2

0,0

-,2

-,4

-,6

-,8

-1,0

-1,2

-1,4

-1,6

Repetitiveness

non repetitive

repetitive

Results

Some more results: TXL

TLX:

-Mental demand higher for nrep;

-Temporal demand remains higher for nrep, from Run 1 to Run 2 decrease stronger for h-l as increase for l-h

-Performance rated higher from nrep

-Effort rated higher from nrep

Straussberger, S., Kallus, W. & Schäfer, D. ICRAT 2004, Zilina

Results

Some more results: TSI

TSI:

-Attentiveness remains constant for repetitive (rep) group and decreases for non-repetitive (nrep) group

-Fatigue higher for H-L group; higher von nrep in Run 1 and rep in Run 2

-Concentration decreases more for nonrep

-Sleepiness: increased over time, but more in Run 2 for h-l

Straussberger, S., Kallus, W. & Schäfer, D. ICRAT 2004, Zilina

Methods

Participants

24 Enroute ATCOs

18 male, 6 female

21-47 years

Straussberger, S., Kallus, W. & Schäfer, D. ICRAT 2004, Zilina

Methods

Straussberger, S., Kallus, W. & Schäfer, D.

Proceduremin

1. Welcome, Summary of Controller Handbook, open questions 102. Preparation of physiological measures + Questionnaires 403. Training 404. Baseline, Scales 55. Run 1 456. Baseline, Scales 307. Run 2 458. Baseline, Scales 309. Break with vs. without activity 1010. Run 3 1011. Baseline, Scales 512. Performance Tests 1513. Remove equipment 514. Debriefing 10

Total Time 295

Session Start 8:00 vs. 14:00ICRAT 2004, Zilina

Methods

Dynamic Density

Straussberger, S., Kallus, W. & Schäfer, D.

• Traffic density (amount of AC)• Traffic complexity

– Heading Change– Speed Change– Altitude Change– Minimum Distance 0-5 n.mi.– Minimum Distance 5-10 n.mi.– Predicted conflicts 0-25 n.mi.– Predicted conflicts 25-40 n.mi.– Predicted conflicts 40-70 n.mi.

• (Controller intent)Laudemann et al. (1998)

ICRAT 2004, Zilina

Methods

Independent Variables

Straussberger, S., Kallus, W. & Schäfer, D.

-Repetitiveness (repetitive vs. non-repetitive conflict patterns)

-Sequence of Dynamic Density in Traffic (high (H) - low (L) vs. H - L)

-2 Runs (1. Scenario vs. 2. Scenario)

-(Time over Scenarios)

-[Activity in Rest Break]

ICRAT 2004, Zilina

Methods

Further Variables

Straussberger, S., Kallus, W. & Schäfer, D.

Continuous Variables:

-RSQ (Recovery-Stress-Questionnaire, Kallus, 1995)

-ACS-90 (Action Control Strategy, Kuhl, 1992)

-Boredom Proneness Scale (Farmer & Sundberg, 1986)

-Morningness-Eveningness-Scale (Horne & Ostberg, 1976)

-Big Five Markers (Goldstein, 1992,1999)

Control Variables:-Initial State (FAL), age, sex, nationality, mother tongue, ratings for working position, experience, actual worked sector, handedness, body weight, body height, vision, smoking, time, room temperature, movement, respiration