Information Processing and Situational Awareness

Human Information Processing

Human information processing is a system to describe how people notice, store, integrate, retrieve and use information.

It looks at stimulus and response whilst providing complex problem solving and decision making.

Information processing passes through several phases from Sensory Memory -Working Memory - Long Term Memory - Response Formulation - Action.

All of these are critical to good decision making - when these aren't aligned then human error is a byproduct.

Attention

Stress

We can usually time-share easily, but in times of stress or over-concentration on one task, this can be inhibited.

Saturation can have the same result. The brain is overwhelmed and 'load shedding' occurs.

Calls from ATC often go unnoticed when pilots are dealing with an emergency.

"The pilot turned base with the undercarriage still retracted. The tower controller called and warned the pilot but he continued to approach and landed wheels-up. When asked why he didn't respond to the tower's calls, he replied that he couldn't hear them because of the noise of the undercarriage warning horn. He heard the noise but did not perceive, accept, nor recognise the message that the noise was designed to convey".

"The serviceable aircraft flew into the ground. The crew were discussing the gear-not-down warning light and didn't notice the autopilot had disengaged".

Attention Grabbing

The strength of the stimulus relaying the information must reach a certain level to be detected - sensory threshold.

There is a phenomenon called the cocktail party effect. You can be in deep conversation at a party for instance yet still hear your name being spoken in another area of the room.

This is also the same effect when a pilot immediately responds to their call sign in a dense air traffic environment.

Habituation can occur over repeated exposure.

Perception

Perception is the process of receiving information through the senses, analysing it and making it meaningful. It is a recognition process.

What we perceive can be biased, confused, mis-read or misled.

The amount of sensed stimulation that is perceived and integrated correctly depends on experience and expectation.

If we recognise the stimulus through past experience, we can readily absorb it (e.g. hot plate and pain).

Another example is radio messages from ATC. Pilots can understand the pattern through experience where other people cannot.

An expectation of what the message will be is helpful. However, this has led to accidents in the past.

Perception Abnormalities

Problems can arise when we false pattern match.

Hallucinations - false perception of something that is not really there e.g. abnormal engine noises at night.

Illusions - false perception due to misinterpretation of the stimuli e.g. optical illusions such as sloping ground, false horizons.

Problems in perception also arise when we receive conflicting information from different senses such as eyes and balance.

Expectation and Mindset

We tend to finish sentences in the way we expect them to end.

In the line-up at a runway, we expect to hear "cleared for takeoff". Therefore, we are mentally prepared for take off. If the actual instruction is: cleared for a Tumut 35 departure" we may not hear anything beyond "cleared for..."

There is also a bias involved in what we see and what we expect to see. For instance on a cross country flight, we may convince ourselves that the ground features below match the mental model of our position.

This inflexibility is called mind-set (confirmation bias).

Cognitive Biases and Heuristics

A significant proportion of mistakes are caused by incorrect situation diagnosis connected to human cognition particularly at times of high workload.

Expectation Bias - fills in the blanks in communications to understand incomplete messages - sometimes the person 'hears' what he/she expects to hear (as in the Tenerife crash). Can apply to outside of communications also.

Availability Heuristic

when workload is high the brain tends to put more emphasis on the most available and recent information rather than the most reliable and relevant. This includes previous personal experiences and the emotional influence they may have had.

Confirmation Bias -

a hypothetical diagnosis that is hard to counter (mindset).

We emphasise evidence that supports mindset

We disregard evidence that goes against mindset

Cognitive Dissonance

"the state of having inconsistent thoughts, beliefs, or attitudes, especially as relating to behavioural decisions and attitude change."

For example, someone who smokes, usually knows that smoking is bad for them (causes cancer etc.) but still does it. They are said to be in 'cognitive dissonance'.

Confirmation bias often works to 'resolve' the dissonance.

Processing

Processing - What should I do about it? WM can be equated with the CPU/RAM of a computer. All the processing happens here but has a limited capacity.

Data remains in the memory as long as it is being used (we can remember a dream but it fades very quickly).

A memory from ATC will remain in short term memory long enough for you to follow instructions.

Change frequency to one three two decimal one

ATC instructions that are long (e.g. route clearances) should be written down.

Working Memory

The role of the STM/WM is a short-term store of about 30 seconds

Normally we can store around 7 +/- 2 items

Increasing Capacity of Working Memory

Nominal 7-9 items can reduce under times of stress, fatigue or distraction

Increase capacity by

Grouping (chunking) information

Mnemonics e.g. PUF on short finals, IM SAFE

Association (verbal, visual, flow)

Cards

Rote

Saying a written instruction aloud

Visualise the words or numbers

Multi-Tasking

A theory is that you can 'multi-task', but in effect we prioritise (and switch between tasks. e.g. whilst monitoring attitude and flight path we also raise flaps) .

However, when mental workload is too high, our ability to do this declines.

Startle Effect

The 'startle effect' is beginning to make traction in aviation psychology.

A sudden unexpected event that causes the pilot to experience an uncontrollable, automatic reflex (both physical and mental) - fight, flight or freeze. Maintaining effective situational awareness prior is key to reducing the effects of startle.

Think of Captain Sully in the Hudson River ditching or the Colgan Air Q400 accident.

Long Term Memory

Information filed here for later use, after being rehearsed or encoded in working memory. May be retrieved several mins later or decades later.

Practically unlimited, no evidence to suggest we run out of room like the hard-disk of a computer.

Information seems to be stored in three areas

one involving motor skills - procedural

one involving meaning (knowledge) - such as the use of language

one involving events or episodes

The information can be reconstructed and brought into working memory when needed but not always accurate.

Although items are categorised into long term memory forever, there may be problems or delays in retrieving them.

Improve this by periodically recalling memory e.g. engine failure procedure

Brain will associate new data that is sensed by associating it with what is already stored. Totally new info takes longer as brain must find a place to store it.

e.g. your first flight in a DA40 compared to first flight in DA42.

Motor Skills Memory

Implicit memory

Where our 'skills' are stored

E.g. Walking, riding a bike, tying a shoe lace

Hard to teach

Repetition required to embed

Semantic Memory

The meaning memory of the long-term memory is also called the semantic memory. Information (knowledge) is stored in words and numbers. Knowledge in this part includes the meaning and use of language e.g. aircraft limitations, check-lists etc.

New material being learned needs our full attention.

Learning in situation e.g. learning checklists in an actual cockpit helps with encoding and later retrieval. The environment reinforces the memory (visualisation).

If new info is understood it can often be retrieved by logic.

Event Memory

Also known as episodic memory. Noteworthy events and episodes in your life are stored here.

Often inaccurately stored due to our attitudes and preferred outcomes (think, should, wish)

Accident investigators often faced with 'expert witnesses' who's recall of an event is not completely accurate.

A trained pilot unconsciously applies her/his knowledge and expectations as what should have happened.

Non-expert witnesses can be better.

Levels of Processing

Having accessed the memory and completed the perception/recognition/decision making process the brain now directs action signals for execution.

Conscious control - pilot makes a decision and acts.

Sub-conscious control - in many routine cases the pilot's brain recognises a previously matched set of data and applies motor skills that have previously been learned (riding a bike) as an unconscious reaction.

Conscious control

the active intervention of the mind to direct control of the situation.

Having completed a direct action (e.g. avoiding a conflicting a/c) the brain may relinquish control to subconscious control routine processes (straight and level flight).

Now the conscious mind can concentrate on navigation or comms etc.

Senses continue to check output of control inputs or decisions and make corrections.

Situational Awareness

Situational awareness is a term used to describe a persons awareness of their surroundings, the meaning of these surroundings, a prediction of what these surroundings will mean in the future, and then using this information to act.

3 levels

Perception

Comprehension

Projection

Perception

The ability to notice things.

Comprehension

The ability to understand what has been noticed.

Projection

The ability to think ahead and predict the affect of what has been comprehended.

Loss of Situational Awareness

Loss of situational awareness is correlated with poor system performance and errors.

Studies have shown 77% of situational awareness errors are made at the perception level of SA. 21% at comprehension level and 1.5% at projection level.

(Data from Jones and Endsley 1996)

See Stream reading for more information and data

Factors Affecting Situational Awareness

System Design

Stress and Workload

Automation

Physiological Factors

Preconceptions

Abilities/Experience/Training

Communication

Enquiry

A means for increasing your own situational awareness.

Advocacy

A means for increasing someone else's situational awareness.

Group Situational Awareness

Group Situational Awareness

The shared ability to look and listen

Individual S.A. is becoming aware

Group S.A. is being made aware

Captain's S.A. + F/O's S.A. + C/Crew's S.A. = Group S.A.

Group situational awareness is ultimately limited by the situational awareness of the Captain.

Enhancing Group Situational Awareness

Effective crew briefings

Use all resources

Consider all crew member inputs

Avoid arguments

Avoid thinking of being a 'winner' or 'loser'

Use advocacy and enquiry

Move to assertion if required

Communication