The Startle Reflex: Shaken, not Stirred Part Two

James “007” Bond insisted on his martinis “shaken, not stirred,” but unfortunately such is not always the case after we get a sudden jolt of surprise. Neuroscientists call this the “post-startle period of cognitive dysfunction,” and last month we detailed the first few seconds after a major scare and what characterizes this “post-startle reflex.” 

It is a brief period of cognitive dissonance generated in the brain by our fight-or-flight system that makes it impossible to think clearly and solve critical problems. We are all wired a bit different, but no matter how quickly we can recover, decision errors we make in this crucial time can be fatal if they occur during a critical phase of flight.

Dr. Jeffery Schroeder, Chief Scientific and Technical Advisor to the FAA for Flight Simulation, has studied these decision error risks with simulator studies involving the deliberate startling of commercial pilots. As we would have suspected, his tests showed significant deficiencies in post-startle decision-making. He found that 33% of the pilots performed inappropriately or ineffectively following a startling stimulus. The same study showed that 78% of pilots failed to complete a stall recovery using the correct procedures. These are the times we talked about last month when the cortex, where good solutions are stored, are bypassed by the fight-or-flight centers in the amygdala. Neuroscientists have an appropriate name for this and call it “amygdala hijack.” Also, the pilots in his tests were aware that a startling or unusual event would occur, but in a true sudden emergency with no warning, it is likely that these percentages of bad decisions would be even higher since there is no anticipation of the coming event. The final results of all these studies show that the effect of startle and acute anxiety on working memory can be totally debilitating, replacing constructive problem-solving skills with task-irrelevant, anxious thoughts and incorrect reflexive muscle movements. We explored a lot of the negative impacts of all this in the article on “Brain Freeze” that leads us down a dangerous pathway including narrowed attention, tunnel vision, failures to search for a safer alternative, longer reaction time to come up with a problem solution, and, worst, the real degradation of our problem-solving skills. All of these studies show that it is during the post-startle phase of confusion that it is hardest to avoid mistakes.

Clearly these stress effects are a big risk in aviation during a critical event where robust problem-solving and decision-making skills are most needed. There are some lessons we can use in all our daily activities and especially in the cockpit to avoid an error in the first few seconds of the startle response. The most important first thing to do when your bell is rung is NOTHING. Don’t do anything, don’t overreact; force yourself to wait a moment so you can make a thought-out decision and not just a reflexive reaction. We talked about some useful skills and ways to minimize the post-startle jumble in the article onSwinging at Beach Balls that detailed skills for maintaining focus on your surroundings (think back to building your SA picture from a few articles ago). The better and more accurate your SA picture is, the quicker you can reorient yourself to your current predicament and recover from being shaken up. These skills help you find short-term memory solutions narrowed down to ones that would solve the immediate problem and you don’t have to spend time fumbling around in the fog looking for a correct action. The post-startle response is caused by all those stress chemicals pumped into your bloodstream. Useful techniques to clear those acute startle chemicals out of your head are a topic I covered in the article on stress you can review. Take a huge deep breath, relax your muscles, and wait for your heart to stop racing before reacting to something.

Using your own heart rate to judge your decision-making capacity has real value. The FAA has done some interesting studies on this issue of “tachycardia” (rapid heart rate) and has correlated the startle reflex and recovery with heart rate. We all know that pounding feeling in our chest when we get startled, and the same chemicals that jumble our thinking drive our heart since they’re all part of the same fight-or-flight reaction. So it is not surprising that those heart rate changes correlate well with problem solving and commission of errors. When healthy volunteers were plugged into some equipment to randomly give them a scare, it turned out that heart rate jumped up and errors increased proportionately, but the more test subjects were presented with the same surprise the less their heart rate went up and the sooner heart rate and decision-making returned to normal. This means that the less novel and the more practiced the response to the event, the fewer errors in that post-startle time. This is physiological proof that planning and training for emergency scenarios will decrease the chances of a bad outcome. It also gives you a way to monitor yourself and know when it’s safe to make a decision. As your heart rate comes down your chances of making the right decision go up. This is the scientific basis that proves the more you have practiced, drilled, thought about, and “pre-lived” possible emergency scenario recoveries, like upset recovery training, the less severe the startle reflex will be and the quicker you can recover to make a good decision. Just like Doug Downey said about his Bandit 650 flight, “dare this jet to fail” and have a plan to deal with it already hardwired into those cortical short-term decision areas in your head.

It’s crucial for survival that a sudden stimulus immediately gets our attention, but with practice and repeated training you can get your brain to recover quicker and reduce the risks of mistakes after the jolt. Old James Bond had it right; take life’s surprises like James took his martinis, shaken, not stirred.

Kenneth Stahl, MD, FACS
Kenneth Stahl, MD, FACS is an expert in principles of aviation safety and has adapted those lessons to healthcare and industry for maximizing patient safety and minimizing human error. He also writes and teaches pilot and patient safety principles and error avoidance. He is triple board-certified in cardiac surgery, trauma surgery/surgical critical care and general surgery. Dr. Stahl holds an active ATP certification and a 25-year member of the AOPA with thousands of hours as pilot in command in multiple airframes. He serves on the AOPA Board of Aviation Medical Advisors and is a published author with numerous peer reviewed journal and medical textbook contributions. Dr. Stahl practices surgery and is active in writing and industry consulting. He can be reached at [email protected].

Related Articles