Brain Freeze: Part TwoBrain Freeze Part Two

We left off last month talking about how our head functions to process information, or block it out, and the cognitive activities that define situational awareness (SA).  

We also talked about what goes on in a pilot’s brain when the senses become tunneled and SA disappears. Tunneled senses pose one of the greatest safety risks in the cockpit, as a pilot is simply not aware of all problems that may exist. This results in a loss of situational awareness and that’s like a big ugly boogeyman sneaking up behind you. Even in the face of a great risk, you are blindly unaware he’s there about to strike. Let’s dig deeper into skills needed to maintain SA or, if SA is lost, to reestablish the big picture and get it back before disaster strikes.

Dr. Mica Endsley, a former chief scientist for the United States Air Force, has studied this topic extensively and defines the big picture of SA as the combined product of three stages: (1) the perception of elements in an environment, (2) the integration of those elements into a comprehensible meaning, and (3) the projection of that meaning into the future. In order to form this big picture, the brain has to use the elements of sensory input and data processing I have talked about over the last few months. Unfortunately, these are the same processes that are so at risk to fail during stressful situations. These include working memory, perceptual capacity, motor skills, visual processing ability, and temporal processing ability. When any of these thought processes or sources of sensory input get tunneled, the big picture disappears.

To prove our model that tunneled senses is the cause of the loss of SA, it’s interesting to layer our scheme onto real aviation accident data and see how it fits. The types of aviation accidents that are attributed to loss of SA have been studied in the Aviation Safety Reporting System (ASRS) database. The errors were grouped into the three major categories that comprise the three stages of SA. Digging into the ASRS data, researchers have identified Level 1 errors as things like a failure to correctly perceive information or failure to monitor and observe available information. That’s what happens when the pilot suffers from auditory or visual tunneling. Think back to the example last month of the pilots who landed gear up with the gear position warning horn blaring away. Level 2 errors are failure to comprehend the situation that in our model would be attributed to tunneling of the thinking process.  This is what happened to the pilots on Eastern flight 401 that plunged into the Everglades while the pilots focused only on the landing gear lights. Level 3 errors are due to a failure to accurately project the situation into the future like grabbing the first instinctual reaction and not making carefully thought out actions.

The large majority (76%) of the mistakes were identified as failing to perceive or understand information (Endsley’s Level 1 SA); 20% were Level 2 (incomplete mental model or using an incorrect mental model); and only a handful (3%) were Level 3, reflecting failure to make correct projections into the future. These data fit our model of tunneled senses nicely.  The vast majority of accidents are due to losing the big picture that is caused by stress-related tunneling or intentionally tunneling your senses. This is proven by the high incidence of accidents due to talking on the phone or texting while flying or driving and not concentrating on the most important tasks.

With this understanding, it’s time to figure out how to maintain SA or get it back if lost. The first step in getting back the big picture sounds trite, but still is true. Don’t lose your SA in the first place. The amount of time that any person can concentrate and maintain their focus varies among individuals and circumstances. Factors that negatively impact our ability to hold onto the big picture include fatigue, altitude (decreased density altitude means decreased oxygen concentration), distraction (like hunger) and boredom. I talked about all these factors in the post a while back on diet and energy use.

The 3-stage picture is time sensitive; it’s very short-lived and needs to continuously update. Maintaining SA requires diligence and constant reassessment of the all three elements of SA. To accomplish this requires repeated instrument scans and scans outside the cockpit that refocus your brain on your surroundings and flight parameters. This needs to be done several times each minute or boredom sets in, senses are dulled, and that ugly boogeyman creeps into the cockpit. All this effort to maintain your SA is well worth it, since getting your SA back is a much harder task than keeping it while you have it.

Neuroscientists who study SA use the term “situational awareness recovery” to refer to the process of getting SA back after it is lost. They use the acronym SAR, which also stands for “search and rescue,” a term our military pals use and which is a perfect analogy to outline the important steps of reorienting perception and sensory input. The loss of situational awareness takes place when there is an interruption, either self-induced or due to a sudden change in flight dynamics. SA loss is worsened by an oversight, a hasty inference, or a decision based on incomplete knowledge or misinformation, especially under conditions of heavy workload or the added stress of time compression.

This has been studied in the lab by interrupting test subjects carrying out an assigned mental task. The duration of these interruptions was only about 4-6 seconds. But even with those short bursts of interruptions, accuracy when returning to the task at hand was significantly reduced, indicating deterioration in SA. In addition, after each interruption participants took longer to initiate the next action, indicating further delayed SAR. The decreased level of SA from repeated interruptions required the study participants to engage in SAR to refresh their memory. For this to happen, study subjects had to “re-fixate” on objects that were previously looked at (scanned) in order to re-prime their memory and refocus on the environment and the task. In reacquiring their previous SA, the study subjects had to reactivate their original goal through something they called “associative priming.”

After being interrupted during SAR, participants fixated more on objects that were previously looked at and fixated on relevant novel objects less than during continuous task performance. Re-fixations act as contextual cues that prime the memory for the situation and reestablish SA.  The perceptual and cognitive processes needed for SAR include re-fixating on cues in the environment, increasing your scanning frequencies, and shortening fixation durations on one element in the cockpit. This study also showed why it’s so important to hold onto SA as the opposite is also true; when there is no interruption SA is higher, enabling the participant to allocate attention to detect and solve new problems that pop up.

All these studies prove the things we have speculated on. When SA is lost and senses tunneled, new wrinkles in the environment are harder to spot and it takes longer to react and solve novel problems. A simple method pilots can use to find lost SA is to change your point of view. Take a giant step back to observe your perceptions from a distance. To maintain your level 1 SA, constantly rescan the instruments and scan outside the cockpit. Maintain level 2 SA by continuously reestablishing exactly where you are and reassessing the flight conditions. Describe everything you observed. Start with the broader picture and then capture all the details, formulate a plan, and plan your outs. In the fancy words of neuroscientists, “re-fixate.” Explore possibilities that will help you see more opportunities and solutions around you. For example, fly with the GPS on the “nearest airport” page when things get dicey so projecting a plan out into the future to get your Level 3 SA back is as simple as pushing the “direct to” key.  Don’t let boredom and routine distract you from understanding what’s different in the here and now. Looking for small signals and cues will train your mind to be alert and not stray too far from your big picture.

In the words of an old Air Force flight instructor who taught me how to fly a long time ago, “Never let this airplane take you somewhere your head hasn’t already been five minutes ago.” Even in the old days of flying before pilots understood all the subtleties of the three levels of situational awareness, they knew how to avoid the boogeyman that creeps into your cockpit when you lose the big picture.

Kenneth Stahl, MD, FACS

Kenneth Stahl, MD, FACS is an expert in adapting principles of aviation safety to the healthcare industry for patient safety. He also writes and teaches pilot safety principles and error avoidance. He is triple board-certified in cardiac surgery, trauma surgery, surgical critical care and general surgery and holds an active ATP certification and a 20-year member of the AOPA. Dr. Stahl practices surgery full-time and is Healthcare Division President for Convergent Performance, an industry leader in teamwork, checklist and accountability training and consulting. He can be reached at [email protected]

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