People often mistake situational awareness and human attention as being the same thing. However, this is not entirely the case as both are seperate entities that are linked and affect one another depending on the situation. In aviation, situational awareness and attention plays an important part in the safety of aircraft operation as the lack of these two aspects can lead to dire consequences. This article aims to discuss the characteristics of situational awareness and human attention and how they link together.
A basic definition of situational awareness can be a person’s state of knowledge or the mental model of the situation around him or her. Endsley (1999) defines situational awareness as “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” and is divided into three levels:
- Level 1- Perception of the elements in the environment.
- Level 2- Comprehension of the current situation
- Level 3- Projection of future status
To see a detailed description of the definitions and levels of situational awareness refer to main article Situational Awareness
Situational awareness in an aviation context
In the aviation context situational awareness falls on clearly defining its elements which are not specific to a particular type of aircraft and mission but, generally across many types of aircraft systems. According to Endsley (1999) there are certain specific situational awareness requirements when it comes to aviation. They are:
- Geographical situational awareness: This involves the knowledge of one’s aircraft, other aircrafts, terrain, airports, waypoints, climbing descending points etc.
- Spatial/ Temporal Situational awareness: involves aspects such as, attitude, altitudes, velocity, headings, and G forces. Flight path, aircraft capabilities etc.
- System situation awareness: Involves the management aircraft systems status.
- Environmental situational awareness: Weather formations, IFR versus VFR conditions, projected weather conditions etc.
- Tactical situational awareness: In military aviation.
Attention as defined in Matlin (1998), “is a concentration of mental activity”, and is divided into two interrelated categories:
1) Divided Attention
Divided attention involves attending to simultaneous tasks or basically paying equal attention to several tasks. As mentioned in Matlin (1998), the human perceptual system can only handle some divided tasks or simultaneous tasks which require equal attention, but incidentally fails when the tasks become highly demanding. This was demonstrated using 'The Duncan Experiment’ which required participants to make simultaneous judgements about two objects (as to what the object was and to where it was). The participants started making errors when they were faced with two objects simultaneously as opposed to one (Matlin, 1998, p.43-45).
However, divided attention can be improved by practice. According to Matlin (1998) A study involving college students, who had to read stories silently at the same time write irrelevant words read out by the experimenter showed that practice does indeed improve divided attention. At first the students did not perform well. But after several practice sessions they were even able to categorise the dictated words. In aviation a good example is the need to communicate and fly an aircraft at the same time. This task is fairly difficult for an ab-initio or the novice pilot. But for the professional or experienced pilot, doing this would be fairly easy as he/she would have had more practice in this regard.
2) Selective Attention
The second category of attention is selective attention. This type of attention involves situations where people are confronted with two or more simultaneous tasks and they have to attend to one of the tasks while ignoring the other. As Matlin (1998) suggests, “selective studies often shows that, people notice little about irrelevant tasks”, except when the ignored message or irrelevant task involves the name of the listener and maybe, when the voice transmitting the ignored message changes from male to female. For example, when the pilot is concentrating on the task of flying an aircraft, he/she will tend to respond to a communication or radio call which involves his/her call sign. Another good example is the emergency warnings in modern aircrafts have female voices because, as mentioned before, people tend to respond to ignored tasks or information when there is a change in gender.
Selective attention is further subdivided into two categories. The first one being dichotic listening, which involves the division of a person’s auditory attention. It is from experiments conducted through dichotic listening that researchers came to find that people do indeed respond to unattended messages when it involves their own name or when the message transmitter changes gender. The second category is the ‘The Stroop Effect’ which, as mentioned in Matlin (1998), “refers to the tendency of people to take much longer to name the colour of a stimulus when it is used in printing an incongruent word than when it appears as a solid patch of colour”. It is believed that the reason why this conflict occurs is because the Stroop task activates two pathways which compete
with each other resulting in the deterioration of task performance.
Here is a link to a basic test demonstrating 'The Stroop Effect:
Test Demonstrating 'Stroop Effect' (Tam, 2003)
The Link Between Situational Awareness and Attention
1) Accurate situational awareness depends on the deployment of proper selective attention: To fully understand situational awareness it is also important to understand its relationship, but also its distinctiveness from other information processing components such as the working memory and the long term memory. “Thus, we may distinguish between the process of maintaining situational awareness, supported by attention, working memory and long term memory and the awareness itself” (Wickens & Hollands, 2000, p.261).
2) Situational awareness is domain specific (Wickens & Hollands, 2000, p. 261): This means that sometimes people attending to a certain task may or may not be necessarily aware of what they are doing. In a sudden emergency situation in the cockpit, the pilot may have an automatic response which he/she may not be aware of although attention has been given to completing a task. A good example is the engine failure after takeoff drill.
3) Change in the pilots attention state due to stress hence affecting Situational Awareness: There are different types of stressors starting from physical to mental which indirectly effect the workload and hence the situational awareness of the pilot. As mentioned in Endsley (1999), a high amount of stress can have extremely negative effects such as attention narrowing, reductions in working memory capacity etc. this change in the state of attention will increase the workload and reduce situational awareness.
4)Work overload: According to Endsley (1999) this can also affect attention and thus situational awareness as only a subset of the information received can be attended to or the pilot maybe trying to achieve situational awareness, yet suffer from erroneous integration and perception of information.
5)Low workloads: Lack of attention due to boredem leading to a loss of situational awareness, e.g. long haul flights.
6) Automation Complacency: Although automation may reduce stress and workload it may cause the pilot to once again become bored and cause a negative change in attention which will in the end affect situational awareness.
Want to know more?
- Situational Awareness
- Definitions, Levels of Situational Awareness, Factors Affecting Situational Awareness etc.
- Flight Crew Situational Awareness
- Flight Crew Situational Awarenes and Model for Team Situational Awareness.