Applying Cognitive Streaming Theory to Air Traffic

Management

Prof Eric Farmer

QinetiQ, UK

Prof Dylan Jones

Cardiff University

What’s the problem?

• Abstractly: When concentrating on a mental task, how much background sound gets registered?

• Concretely: When concentrating on flying, how much apparently irrelevant radio information is registered by the pilot?

• This is ‘the party line problem’

‘Party Line’

• Is a pilot capable of picking up information from background RT?

• If so, then new technologies that minimise the role of speech (‘data link’) may– Reduce awareness– Decrease safety

Innovation: Cognitive Streaming

• Streaming theory suggests:– Irrelevant sound is registered

• Without awareness

• Even when the person is trying to ignore it

• Even when the person says it has no effect

• But only in an unelaborated form (no ‘meaning’ attached)

Streaming Theory: What are its unique predictions?

• An efficiency penalty for the presence of sound– It interferes with complex task processing

– Tasks with high short-term memory loading are at risk

– Verbal (words) and Spatial (positions in space) information is at risk

• No beneficial effect if improved awareness due to the presence of sound– The meaning of the sound will not be registered

– Complex ‘situational awareness’ will not be developed

The Study

• Use a simple, sensitive task– Short-term memory for co-ordinates– Presented visually – Require a response that can be measured

objectively (the co-ordinates in order)

• Present ATC background speech– Instruct that this is to be ignored

The Method

The material to be remembered: 7 consonants (aircraft call signs) presented

sequentially in 7 random locations (aircraft position);

Hold in memory for 10 secThe irrelevant sound

For 50% of trials irrelevant background radio speech (at 65 dB(A)) presented

The test of memoryRe-present locations and lettersMark order in which either letters or locations

appeared

The Experiment

R

B

Q

M

F

L

V

Recall Callsigns

R

B

Q

M

F

L

VR

B

Q

M

F

L

V

The Analysis

• Average responses over 36 individuals (40 trials per individual)

• Count of number of items in the right order• Measure the speed at which each item was marked

(these not presented today)• Subject to Analysis of Variance• Present graphically (correct responses as a

function of presentation position of callsign/position event)

Results: Correct Responses

Key Findings• Mere presence of

speech reduces accuracy

• Accuracy drops by 20%

• True for spatial and verbal types of information 0

10

20

30

40

50

60

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80

90

1 2 3 4 5 6 7

Serial position

% c

orr

ect serial re

call

Verbal - quiet

Verbal - speech

Spatial - quiet

Spatial - speech

How right was Cognitive Streaming?

• Irrelevant sound damaging to performance

• Short-term memory tasks at risk

• True for spatial and verbal information

What are the unanswered questions?

• Sound is registered and is damaging to task performance, but is it useful?

• Do the effects found in our study generalise to other tasks?

• How can disruptive effects be avoided?

• Are the effects present in real-world tasks?