Problem-solving, decision-making and communicating are all fundamental requirements for maintaining a safe and efficient aviation system. To help maintain and improve aviation it is important for people within it to understand the basis of information processing and cognition, and the role that memory plays in optimising these functions.
Because of the complex make-up of the human brain, many researchers have developed functional models that help to simplify and show how the brain works so that we can understand it better. The Atkinson-Shiffrin model is a common model that is used to demonstrate how each stage of our memory interacts with the others so that we can process information from our surrounding environment.
The Atkinson-Shiffrin Memory Model (image embedded from Educational Psychology Interactive on September 25 2011)
Our sensory memory, or sensory registry, receives a large and continuous amount of information from all five of our senses. Because of the large amount of information entering the sensory register it is only held there for a very short amount of time – usually for about 1 second – and we cannot prolong this time by using memory expansion techniques. However, one of the key benefits of the sensory memory is that it allows us to recall information for a short period of time, even if we have not been paying attention to it. This is why, if you are in a classroom environment and you are focusing on the good weather outside rather than on what the teacher is saying, you can often recall a question and give a response to it if it is unexpectedly directed at you.
The ability of the sensory memory to allow subconscious recall can play a vital role for pilots and air traffic controllers for radio transmissions. In a high traffic area, it may give a pilot the ability to hear all of a message, even if they only become aware that the message was addressed to them at the end of it when they heard their call sign.
Short-term memory is often referred to as working memory because it is the place where all the ‘work’ is done. This is where a person’s thinking, learning, understanding and decision-making takes place. Our working memory is capable of processing a large amount of information, however it is limited by its capacity to only store and process 7 ± 2 pieces of data at any one time. One way to overcome this limitation is by ‘chunking’ information.
Chunking helps to increase the amount of data that can be used by grouping clusters of individual data together to make one chunk. This can then be retained as one piece of information. For example the mobile telephone number 0-2-5-8-1-9-2-7-0 is right on the limit of the 7 ± 2 pieces of data that the working memory can effectively process at any one time. If trying to remember this number to make a call, no other new information would be able to be processed in the working memory. Any new piece of information that comes in would either replace old information (the last 2 digits of the phone number may be forgotten), or the new information itself may be forgotten immediately. However, if the digits are chunked together so that the number is recalled as 025-819-270 it will be much easier to remember and use. It will also allow new information to be processed in the working memory at the same time. Information can stay in working memory for around 10 – 20 seconds, although this time limit can be extended if the data is repeated over and over again or if it is processed further.
Working memory enables further processing by either initiating an immediate response or by integrating the information with other working memory or long-term memory information before initiating a delayed response based on internal processing. For example, if an aircraft traffic avoidance warning goes off, the working memory will either initiate an immediate response – which may be to turn the warning off straight away - or it may integrate the warning with other information in the working memory – radio transmission of another aircraft in the area combined with details of current altitude, heading and airspeed to determine that there is no threat if they maintain their current course.
In contrast to short-term memory, the information that can be held in long-term memory is vast and can be stored for a very long time. Information that has been stored in the long-term memory is classified into two types: semantic or episodic.
This is the memory that allows us to understand and apply meaning to our world. It is where we are able to store and retrieve all factual information and general knowledge that we have been taught. The knowledge that is stored in our semantic memory links to all other knowledge to create ideas and concepts that allow us to navigate through daily life. Information stored in our semantic memory can be recalled at short notice and is generally said to be stored there for a lifetime (when we think that we have forgotten something, it is often because we are unable to find where it is located in our memory system, not because it actually has been forgotten).
This is the memory that is gained through personal experience of events in our lives that have occurred at a specific time and place. Episodic memory is stored much like a video in our minds and allows us to recall specific events such as remembering where we were and what we were doing when the terrorist attacks on the World Trade Centre took place on September 11, 2001. Episodic memory is very malleable and can be influenced by what we thought should have happened, as opposed to what really did. This can cause problems for air accident investigators when they are trying to gather accurate details of what happened before, during or after an accident. A pilot and a passenger who have experienced the same incident may have different views on what happened. Although the pilot may be more proficient in the technical details required for flying, their recall of the incident may be biased by what they thought should have happened in such an event. The passenger, on the other hand, may be able to recall a much more accurate picture because of their lack of preconceptions involved with the flight.