Sensory Information Processing
During the day a person makes hundreds of decisions. Flying an aircraft is no different, the pilot must use his decision making skills continuously.
The pilot, unfortunately, cannot follow this course of action as the aircraft will eventually run out of fuel. The use of information and decision making is a complicated process. The neural pathway through the brain where information is received, a decision taken and a response executed are too complicated for this course. A simple model of what is called Human Information Processing (HIP) follows.
A physical stimulus has to be received by the receptors: (Stimulus > Receptors)
- Sight > Eyes
- Sound > Ears
- Taste > Tongue
- Touch > Proprioreceptive System
This raw energy is unusable to the brain and needs to be converted (transduced) into electrical impulses.
Initially the information is sent to the Short Term Semsory Memory. The time that the information is stored is limited and depends upon the attention that can be paid. Information from the two main senses are held in:
Visual sensory store which lasts for 0.5 to 1 second
Auditory sensory store which lasts for 2 to 8 seconds
Once there is enough processing capacity in the brain then the information is passed on to the area of perception.
Attention is paid during each of the following processes. The amount of attention that can be paid to each piece of information is limited as will be seen later in this chapter.
An interpretation or impression based on one's understanding of something.
Perception is the process by which the brain recognises and interprets the transduced stimulus which has been held in the short term sensory memory. In the perceptive stage the mind starts to build up a mental model.
This entails building a 3-D model which builds pictures in our minds of:
- Where we are.
- Where we are going.
- Where we have been.
It is true to say that our mental model is our conceptual way of understanding:
- What an object is.
- How that object works.
- What effect that object is going to have in our life.
Perception is based on the information we sense and our expectations of the world.
Perception is based on the following inputs:
- The processing capacity of the brain.
- Past experience.
Unfortunately, once we have reached the perceptive process it is difficult for us to change our minds. It is at this stage that the human being is most likely to fall into the problem of Confirmation Bias.
Confirmation Bias is part of the human error process that occurs when a false perception is made. It is a situation where a person has made a decision and only believes information that confirms that decision.
- The working memory and long term memory.
- The motor memory system.
Any contradictory information is ignored.
Ultra-short Term Memory
If an immediate response is required then the brain replies on impulse using the "ultra short memory". This memory can retain sensory inputs for about a second. This does depend on external factors such as strength of impression.
In the ultra-short term memory, material is processed very quickly according to its current importance. Importance or priorities will vary from person to person and with the situation.
Cocktail Party Effect
Cocktail party effect is one way that the brain uses this ultra short memory. A crowded Friday night bar where you are in conversation with friends. You are concentrating on your group when a person behind you says your name. Without altering expression you immediately change your attention to the other group.
Working Memory or Short Term Memory
Both terms are frequently used. Consider the following. If a pilot hears a warning bell on a flight deck then they will probably react in one of two ways:
- Switch off the sound in which case an immediate response has been made.
- Hold the information in memory whilst a search is made in order to identify the problem.
The above uses a continuous process where information is constantly entered and recalled from memory. During this period a decision has to be made where the information is stored - the short term memory or retrieval from the long term system.
The central decision and response channel can only work one problem at a time and is thus a choke point within the brain.
Short Term Memory and its Limitations
When the brain accesses the short or long term memory system the short term memory will store information for a short time.
Used to retain information that is not needed in the long term memory, the short term memory only retains information for a limited period and its capacity is limited to:
- 7± 2 unrelated items of information that can be held for approximately 10-20 seconds unless active rehearsal is used to retain the information.
- A process called "chunking" can increase the number of items.
- A telephone code 041 is held as one item not three.
- An area code 01455 is held as one item not 5.
- 01455 477686 would be retained as 2 items not 11 which would overload the short term memory.
eg: the use of telephone numbers
Short term memory is prone to interference and any interruption can and will cause the loss of information.
You need to phone a person but do not know the number. You look it up in the phone book and start rehearsing it as you go to the phone. Before getting to the phone you are interrupted for about 30 seconds by something. The short term memory loses the phone number and you have to start all over again.
The short term memory is prone to a problem known as environment capture. A frequently operated skill in the same environment (a habit) where the pilot has not made a conscious decision to operate the skill.
When flying in the traffic pattern. Pilots who delay undercarriage selection somehow have this information dislodged from the working memory especially if the delay is by some form of interruption like ATC instructions. The event will generate a standard response from what becomes a boring activity, flying several uneventful circuits. The pilot may make the final gear down call because he always makes it at this time. The mental model is completed and the pilot believes he has selected gear down. Only when the aircraft scrapes down the runway does the pilot realise that he has failed to select the gear.
Long Term Memory and its Limitations
Long term memory has two distinct parts:
This is the store associated with what we know and do: the understanding of a word; how to fly an aircraft; facts - London is the capital of the UK.
This area of the brain stores all the information that is learnt, including that information we will never use. If a word or fact is forgotten it is because the neural pathways are forgotten, not that the information is lost. The information is stored in an area of the brain that has not been accessed for a long time.
Episodic memory is a fluid memory that remembers events that have been experienced. It is coloured by our desires and expectations. Stories are not remembered factually but reviewed and changed to suit the teller's needs.
In eye witness reports episodic memory can have problems. Think about the reporting of aircraft crashes:
- All aircraft burst into flames before they crash.
- All pilots fly the aircraft away from schools, hospitals and houses before they crash.
Other problems occur with the "expert" witness. A pilot witnessing an aircraft crash has expectations of what was happening in the cockpit and will relate these as what he saw. A non-expert witness is more likely to give a better account. Children give the best eye witness reports as their episodic memory has not yet developed.
When a new action is learnt then it initially seems difficult. Like riding a two wheel bike for the first time. Piloting is exactly the same, initial impressions of flying, ATC etc seem to make the task impossible when training is started. Like most actions which are well practised flying is eventually executed by a motor programme. Non conscious actions are used to fly the aircraft whilst talking on the radio uses conscious thought through the decision and response channel.
The motor programme is by-passing the central decision and response channel.
The advantages of using motor memory is obvious, as it extends our capabilities. Action slip is an error process that is caused by the brain using motor memory.
Pouring a cup of tea, whilst watching TV, and then adding sugar to the cup. If there is some distraction on the TV we can find ourselves pouring tea into the sugar bowl. The action of pouring the tea is being carried out by a motor programme, with no conscious thought being applied. With the distraction the process of pouring the tea carries on and we start pouring the tea into the sugar bowl because the brain thinks it has progressed to the sugar stage, or:
BAC 1-11; My first officer was flying the leg. After T/O I carried out the usual checks. Brakes, U/C up, PAX notices off etc. Weather lovely, blue sky. W/V 270/18, temp +30C! At 1500 ft I noticed the flaps were retracted. I thought the F/O had retracted them early. Usually the flap is retracted at 200 ft plus in VFR or 3000 ft noise abatement. Almost immediately he mentioned that the flaps were retracted. "Oh, I see you have brought the flaps in" he said. "No", I replied, "I haven't touched them". He said that he hadn't either. Shortly after this he noticed the U/C was still extended. I raised it. There can be no doubt I raised the flap instead of the U/C after take-off. I had no memory of this. Why would I do this potentially dangerous thing on an aircraft with which I was completely familiar? I have no idea; no sickness, no stress, nothing dramatic personally.
Once the memory has been used the brain has to make a response. How appropriate the response depends upon the pressure that a person perceives that he is under. The following apply to decision making in all walks of life:
- If a delay is dangerous then a person will feel that they are under pressure to make a quick decision.
- Quick decisions are usually made before all information is processed.
- Where there is stress then a fast but less accurate response is made.
- Sound stimulates the mind better than sight.
- Where a person plans for the expected then it is possible that if there is any change then pressure will make the brain reply with the planned response. (A crew planning for runway 13 from take off to landing. Only when they contact tower is runway 31 given as the landing runway yet they still land on runway 13.)
- An old person may react more slowly than a young person yet the response is usually more accurate.
Attention is a limit to HIP, it depends upon certain factors:
- The limit to the number of items working memory can hold.
- The rate at which information can be passed through the central processing system.
Whether attention is paid to a stimulus depends upon:
- The importance of the stimulus.
- The available attention.
Attention can be described in two ways.
Selective attention is where inputs are sampled and given a priority. Detailed processing can only be carried out on one complex task. If there are too many demands on the attention then information will be lost.
In 1972, a Tristar on approach to Miami experienced a minor undercarriage malfunction. The crew selected the auto-pilot and looked into the undercarriage problem. Unfortunately, the auto-pilot setting was such that the aircraft entered a shallow descent. As the aircraft pproached the ground, ATC, other aircraft, visual and audio warnings tried to attract the crew's attention to their danger. The crew's attention was focused on their undercarriage problem and were filtering out all other warnings, until it was too late to do so. The aircraft crashed killing all on board.
Divided attention can be used to carry out two tasks that do not overload the HIP.
Motor programmes, which are run with no conscious thought, can be consciously checked by a pilot who diverts his attention away from the major task in order to check a sequence of operation.
Stress and Attention
Stress focuses the attention processes. Thus to complete a task, under stress, we focus entirely on that task in hand. This is always to the detriment of other problems.
Once a response has to be made the brain will use one of the three response behaviours.
Skill Based Behaviour
Skill based behaviours are procedures acquired through practice and that are executed without conscious thought. Skill based behaviour is obtained in two distinct manners:
- Concentration on the individual parts of a skill, giving them attention, until practice makes the individual processes second nature.
- Practising the whole skill with concentration on the final product. Eventually a motor programme is made which carries out the skill based response.
Once these skills are acquired then they seem to possess certain characteristics:
- The skill is not easily explained to others. This may cause difficulties if a pilot wishes to pass on the skill.
- If the skill needs to be modified then the component parts must be broken down and re-learnt.
Because of the uses of motor programmes in skill based response a pilot operating a skill makes the decision to do so and then has the attention to monitor the task. But if a distraction is introduced then the pilot may make an inadvertent operation. Environment Capture can also occur in skill based response.
All actions need to be consciously checked, especially those that are using sub-conscious thought.
The errors of skill do not normally happen to the student pilot; they happen to a pilot with experience.
Rule Based Behaviour
Rule based behaviour uses the short and long term memory to carry out actions. Rule based behaviour is stored in the long term memory and involves the use of the central decision and response channel. By using conscious thought the error problems that occur with motor memory skills are bypassed.
Simulator, procedural training or similar work that involves the use of Flight Reference Cards and checklists or plates are examples of this type of behaviour. The only problem relates to the well known saying:
Garbage in - Garbage out
Behaviour Knowledge based behaviour is based on the reasoning powers that a person can use to arrive at a decision. The pilot is able to use his own thinking processes to evaluate and then reach a decision.
When carrying out a task then we must continuously monitor the consequences of our actions. To enable the information to be processed, both internal and external feedback mechanisms are used.
Decision Making Process
"Stay ahead of the Aircraft". How many flight instructors have used this term to tell a student to think about his flying? Does he mean that the student's Situational Awareness is lacking?
When we look at aircraft accidents we have to ask ourselves this question:
Why does a well motivated crew, in an aircraft fitted with all the latest equipment, fail to perform at a critical point during a flight?
It is difficult to define personal or crew situational awareness. Below are some definitions that other people have used:
- Situational awareness is the perception of the elements in the environment within a volume of time and space, the comprehension of their meaning and the projection of their status in the near future (Endsley 1987)
- Situational awareness refers to the up to the minute cognisance required to operate or maintain a system (Adams, Tenney and Pew 1995)
- Situational awareness is adaptive, externally directed consciousness. At a very simple level, situational awareness is an appropriate awareness of a situation (Smith and Hancock 1995)
The above definitions are really definitions for the single crew. For the crew:
- Team situational awareness involves two critical but poorly understood abstractions; individual situational awareness and team processes in a highly interactive relationship (Salas, Prince, Baker and Shrestha 1995)
- Team situational awareness is the crew's understanding of flight factors that affect (or could affect) the crew and aircraft at any given time (Wagner and Simon 1990)
Building Situational Awareness
To help build situational awareness we need to build a 3 D model which pictures in our mind:
- Where we are.
- Where we are going.
- Where we have been
This mental model is our conceptual way of understanding:
- How or why something is working.
- Why something is happening.
- Why a person is behaving in the way they are.
There are numerous factors that affect Situational Awareness:
- System Status
- Dynamics of the Situation
- Standard Behaviour
- Individual Behaviour
- Air Traffic Control:
- Active Monitoring:
- Other Flight Crew
- Navigation Data
- Other Traffic
The mental model that a pilot prepares is created by both experience and expectation. It is therefore, a perception of events. The problem with perception - has the pilot picked up the reality of the situation or is it imagination?
To ensure that the crew situational awareness is equal all crewmembers must remember that:
- In the modern flight desk "knowledge is not power".
- All information must be shared.
- Effective communication ensures that the correct message is sent.
There is a need for an accurate perception of the factors and conditions that affect the aircraft and flight crew before, during and after the flight.
Personal Factors Affecting Situational Awareness
Many factors can cause a loss of situational awareness.
Most tasks require constant monitoring without lapses in attention. Vigilance can be defined as attention to the task in hand such as continuously scanning for other aircraft during a long flight. Vigilance is decreased by factors such as:
- Loss of sleep.
Defined as "to awaken from sleep". In the aviation sense it can be taken as maintaining preparedness for a task. As seen in the chapter on stress a high level of arousal is needed for optimum performance. It is fair to state that a high arousal state requires a high vigilance state. Low arousal leads to low vigilance and very poor performance.
Hypovigilance (hypervigilance) or a state of panic. This worrying state can manifest itself quickly and for no apparent reason. The sufferer becomes illogical in the way that attention is paid to all tasks. Minor problems may take a disproportionate amount of a pilot's attention leading to major problems being missed.
Three levels of Situational Awareness
The pilot requires the skills of not only coping with what is happening now but with the skills of anticipating what is going to happen in the near future. This can be broken down into three Situational Awareness Levels:
- Level 1: Monitoring
- Level 2: Evaluating
- Level 3: Anticipating
Monitoring: There are limits to how much a pilot can see and hear at the same time. Monitoring is an art where the pilot needs to be aware of the present needs and be able to ignore the unwanted. Easy to say - difficult to act upon.
Let us look at some techniques that can move us towards this goal.
Attention is like a searchlight. It can be focussed in one direction. Attention can become so narrow that a pilot can ignore all outside influences to ensure that he concentrates on the task in hand. Narrowly focused attention is useful when solving difficult problems. But who is flying the aircraft?
If the attention is widened too far the pilot will be aware of all aspects of the flight and its environs. The pilot's job requires the ability to focus on a problem and to keep the big picture. Too wide a span and overload is a possibility. In two crew aircraft, redundancy allows for one crewmember to focus on a problem whilst the other is "flying the aircraft".
It is easy to fall into the problem of being sidetracked. These distractions have to be sorted into those that matter and those that don't. Distraction is an easy way to fall into the first stages of an error chain.
As a pilot you need to be able to:
- Keep the big picture.
- Pay attention to detail.
- Not get sidetracked or distracted.
Evaluating: To fall behind the task in hand is one of a pilot's worst nightmares. In this level the pilot needs to evaluate and comprehend the numerous inputs associated with the flying job in hand. In addition to monitoring inputs there must be comprehension as well. This allows the pilot to have a Situational Awareness of the task in hand.
The majority of problems in this category come from difficulties with automation. To stay on top of the situation we must utilise all sources of information.
Anticipating: The pilot not only needs the awareness of what is happening now but needs to be able to anticipate what is going to happen in the future.
This stage ensures that crews have the same awareness of a problem and can both work to the same goal. The crew that anticipates usually stays away from the problems that high workload situation brings.
"What if" is the question a pilot should continuously ask. This question can help in the management of the cockpit environment which includes Situational Awareness. Both pilots need the knowledge of "what", "where", "when", and "who" during any portion of a flight.
A NASA study showed that those crews that brief and debrief a flight are much more effective than those who don't. Both briefing and debriefing allow pilot's to plan the sortie. This plan is the initial basis on which Situational Awareness is built. The brief is the initial sharing of knowledge.
By monitoring, another crewmember's mistakes can be quickly recognised and dealt with. SOPs help by designating the responsibilities of both the pilot flying and the pilot non-flying. Each pilot will have certain responsibilities but must also monitor the situation with the other pilot.
Personality and Behaviour
All people are different. Unfortunately, this can and does complicate our working life. We begin to notice differences from an early age:
- Initially, the physical differences are those that are obvious.
- Psychological differences are then noticed, areas such as:
The differences in personality and behaviour that we show in everyday life are important in aviation. Especially important are the behavioural traits we show when first meeting someone.
We all want a pleasant flight deck atmosphere. We all want to be sympathetic to other peoples needs. A friendly relaxed flight deck atmosphere helps to:
- Foster good communications, which
- Helps Situational Awareness, which
- Leads to a safer flight
A lot is said about personality and behaviour, in simple terms:
- Personality Is what we are.
- Behaviour Is what we exhibit.
The most important aspect of flightdeck operations is the relationship built up between the pilots. As a human we constantly:
- Build relationships with people.
- Break relationships.
- Adapt ourselves to the change in our environment.
A pilot though is not only concerned with the building of relationships with other pilots. From the minute they are at work, the process of building relationships start with:
- Car park attendants.
- Operations personnel.
- Cabin crew.
In communications it was shown how important the way that words are said and body language are. The importance of the following cannot be underestimated as well:
- First impressions.
- Personality clash.
- Cultural or religious differences.
It is important that the pilot recognises the following traits to help flight deck communications:
- A person's personality.
- A person's style and their attitude to life.
By recognising the above traits there is the chance to respond positively and enhance the flight deck relationship.
There are no selection criteria for a person to train to be a pilot. There may be a selection procedure within a company when sponsorship is involved but most pilots self improve and hence are not selected.
Intelligence does not affect whether you can become a pilot or not. But, what is intelligence? A great deal of work has gone into defining and quantifying the subject. Intelligence Quota (IQ) tests are the benchmark most people think of when assessing intelligence. Unfortunately, intelligence is sometimes mixed with the general world wise traits of the human.
Personality can be described as the inner person. It is personality that makes you the individual that you are.
- What you are born with.
- What you acquire over your formative years from:
Once the formative years have passed personality is fixed. However, it can be changed by a traumatic influence such as brain damage after a car crash.
There are times when it is necessary to assess a person's suitability for a task. This is normally achieved in three ways:
- Interview: A subjective way of assessing a person. This is a person's view of another. Most people judge and assess on the first impression and appearance. It is difficult to modify these thoughts even with the passage of time.
- Questionnaire: Where a questionnaire is used techniques such as factor analysis help with the construction of the document. Questions may seem repetitive but the findings are linked and give an assessment of the person.
By using the factor analysis technique, a valid questionnaire for assessing personality traits is constructed and this builds a profile of that individual. One such questionnaire being the Myers-Briggs profile which is widely used within the aviation industry.
Behaviour is similar to the clothes we choose to wear. Think of the clothes you would wear at the following two occasions:
- A funeral
- A barbecue
Behaviour is very much the same. You choose your behaviour to a particular situation like the clothes you wear. If you choose your behaviour, then you are responsible for your behaviour. Unfortunately, you are judged on the way that others see you.
In reality the two statements below dictate behaviour:
Last You never get a second chance to make a first impression.
Behaviour Breeds Behaviour
If you shout at someone, they will normally shout back.
We all have a picture of what we think we are.
This picture is composed of certain values such as:
- Moral values
These values are influenced by our past experiences and expectations on life. These can include events that are both successes and failures. This includes the way that others have reacted to these events especially during our formative years. We live to these values and more importantly judge others with these values.
To help in our self opinion we employ inbuilt defence mechanisms. These also help us in our coping strategies against stress.
The defence mechanisms are set to disguise the presence of a weak or undesirable quality by the emphasis of a more positive quality. In stress coping they may reduce tension by accepting and developing a less preferred but more attainable lifestyle.
These defence mechanisms can also relegate the blame for such problems as shortcomings or mistakes by attributing them to others. The student pilot who fails a test blames the instructor for not teaching the correct techniques.
We are all guilty of turning our back on the unpleasant side of life. With pilots it is the embarassment of watching our own errors when played back on a video screen. Remember "Errare Humanum Est". No pilot has ever flown a perfect sortie, flying is a continuous correction of errors.
Past experience and expectation can have an influence on our behaviour. Behaviour is influenced not only by the accumulation of these experiences but also by the attitudes and awareness of maintaining a friendly relaxed attitude within the flight deck.
Psychologists divide behavioural styles into two basic categories:
- Relationship Oriented: The first consideration is the feelings of others, which rank high in the Decision Making process. A person who is high relationship oriented and low task oriented is considered to have a caring or nurturing style of behaviour.
- Task Oriented: The first consideration is given to the task or goal in the Decision Making process. A person who is high task oriented and low relationship oriented is considered to have an aggressive style of behaviour.
Assertive behaviour has a bad reputation mainly because of its association with aggression. In some ways aggression is a hostile act. It can be argued that an assertive person intends to hurt or injure, maybe even destroy another. In truth, assertion is a device used to ensure that the maximum potential for reaching a goal has been attained. In some ways the following define assertiveness:
- The ability to use words positively and with conviction.
- The ability to defend one's own rights.
Personal assertiveness is required to ensure that:
- A person can take the initiative in any task.
- They can translate this initiative into an action.
- No implication of aggression is perceived.
Over-assertion is regarded as:
- Unusual in certain cases.
The above feelings are felt by people who are subject to over-assertive action. Their reactions can be categorised into three areas:
In its most vulgar form assertiveness can be used as an unscrupulous device to extract total obedience. To achieve "the norm" a person must ask certain questions of themselves. The most important being "What do I understand as the meaning of assertiveness?" We can split assertive behaviour into three categories:
Following are listed a few advantages and disadvantages of each behavioural style.
Where a problem is taken up and a person fails to say anything about the difficulties that it may create.
- The appearance of being virtuous.
- The non assertive may feel more comfortable being used.
- The idea that non assertiveness leads to a quiet life.
- Eventually others lose their respect.
- Resentment may take its place.
- People take advantage of the situation.
- The non assertive gets what they want; but not what they need.
- Self respect is eventually lost.
Doing things in such a way that other peoples rights are violated.
- The less aggressive do what the aggressive wants.
- The aggressive can get the admiration of other people.
- The aggressive feels all powerful.
- Others resent the aggressive.
- Retaliation is always likely after aggressive behaviour.
- In the long term people revolt against the aggressive.
- Lack of respect for others.
Doing things in such a way that other peoples rights are not violated.
- Others understand what the assertive wants.
- There is never a feeling of being manipulated.
- Both long and short term goals are achievable.
- Self respect is always maintained.
- Respect for both oneself and others.
- The assertive risks being given the answer "NO".
- Confrontation is sometimes inevitable.
It is fair to say that a lack of confidence in oneself will usually lead to non-assertive behaviour. The pilot must be able the express an opinion and be able to influence others without aggression.
Case For Assertiveness
Suppression of an aggressive is essential to ensure that conflict is kept to a minimum. Assertive action leads to an inward belief and awareness of one's own abilities.
Non assertive action combined with low confidence lead to misunderstanding and resentment.
Assertive Behaviour: Takes the best of aggressiveness (without the put-down negatives) and the best of non-assertiveness (without loss-of-self.). Assertive action is a genuine direct communication of ideas, wants and needs. Put with conviction a position can be expressed strongly without domination.
Assertive behaviour becomes easier the more it is used. When we respect these rights in ourselves, we are also more likely to act in a manner that respects these rights in others.
Aggressive behaviour denies the rights of others and non-assertive behaviour overlooks these rights in ourselves.
The importance of body language and assertiveness is summarised in the next few paragraphs:
- General: Exaggerated show of strength, flippant and sarcastic style, air of superiority.
- Voice: Tense, shrill, loud, shaky, cold, deadly quiet, demanding, superior, authoritarian.
- Eyes: Expressionless, narrowed, cold, staring, not really seeing you.
- Stance: Hands on hips, feet apart, stiff and rigid, rude, imperious.
- Hands: Clenched, abrupt gestures, finger pointing, fist pounding.
- General: Actions instead of words, hoping someone will guess what you want, looking as if you do not mean what you say.
- Voice: Weak, hesitant, soft, sometimes wavering.
- Eyes: Averted, downcast, pleading.
- Stance: Lean for support, stooped, excessive head nodding.
- Hands: Fidgety, flutter, clammy.
- General Attentive listening, assured manner, communicating, caring, strong.
- Voice Firm, warm, well modulated, relaxed.
- Eyes Open, frank, direct, eye contact without staring.
- Stance Well-balanced, straight on, erect, relaxed.
- Hands Relaxed motions.