Related to Lethal Force Encounters


By Bill Lewinski, Ph. D.

The Police Marksman May/June 2002 pgs 22-28

The purpose of this article is to help officers who have been or may become involved in a lethal force encounter to understand what might happen and why.  I will not predict the reactions of any specific officer to these encounters, but I will reveal the latest research in relation to this topic, as well as explain the adaptive nature of the reactions.


History and Prevalence

 The impact of stress on performance has been a topic of study since antiquity.  In fact, every profession that performs in a high stress environment, whether it’s NASA astronauts or emergency room physicians, is aware of the impact it has on performance and judgment.  The body of scientific literature on this issue dates back to the early 1900’s when theorists were trying to determine what piece of information in the items we observe are able to catch our attention, and how they affect our interpretation of the items.  The study concerned with these concepts was known as “perception.”  In the 1950’s the area of study that focused on understanding these concepts remained perception but also began to be researched by psychologists interested in “attention.”  A significant body of literature can be found from that point until now under both titles.  In the mid 1950’s psychologists interested in perception began to pay attention to the roll of emotion in perception.  There are thousands of articles on the influence of emotions on perception.

 In the 50’s the involuntary nature of attention as it related to intense, novel, emotional, or significant events began to draw research interest.  Psychologists were becoming more aware of perception and specifically, that the narrowing of perception was a product of the receptor, (e.g. the eye or ear) and a product of the mindset or focus.  Fear, panic, anger began to be recognized as having influence on perception.  Industry, particularly aerospace, was interested in the focus and attention problems of humans under the stress of intense or significant events.  For instance, the engineers designing cockpits in fighter planes began to accommodate for the deterioration of human performance in stress by simplifying instrumentation and design.  The industrial psychology literature of the 50’s and 60’s focused on creating environments that made adjustments for human perceptual, cognitive and physical rigidity, and aberrations during high stress.

 Sports psychology became interested in perception and attention in the 1970’s.  Anyone who has watched two outfielders collide as they both went for a fly ball has seen the effect of perceptual tunneling and can understand why it might be important to manage it in the athletic arena.  Even Tiger Woods has commented on how a failure to control his concentration had resulted in his loosing in the clutch.  Athletes have continually reported not hearing the noise of the crowd.  Every sports psychology book published since 1975 has addressed the issue of the “funnel of concentration” and in particular perceptual “tunneling and blockage.”  Sports psychology also began to develop ways to funnel the emotional responses in a stressful activity into something more productive – such as focused, emotionally intense state.

 In law enforcement, these concepts began to surface in regard to shooting situations.  Officers who had combat experience began to find the phenomenon that occurs on the battlefield also occurs in the civilian world in life threatening situations.  Police Psychologists like Dr. Roger Solomon and Dr. Kevin Gilmartin began to note that officers involved in shootings and other high-stress events had increased emotional reactions after these events.   They experienced unusual perceptual reactions or their body, mind and memory worked in unusual ways – confusing and frightening them.  These events began to be call things like tunnel vision and tunnel hearing.

 In the mid 1980’s Calibre Press’ Street Survival® Seminar and the Tactical Edge continued to spread these concepts of human performance under stress into the law enforcement world.  Since that time almost every law enforcement seminar pertaining to shooting decisions or post shooting trauma, has included perceptual tunneling and blockage.



Today’s Understanding

 Tunnel vision and tunnel hearing are common terms in law enforcement today.  We now know that they relate to a variety of changes in both the brain and the sensory systems when a human or animal experiences a threatening or stressful situation.  However there is still much misunderstanding about how humans perform in highly stressful events and these phenomena on law enforcement officers.

 A study conducted by Drs. Honig and Roland of the Los Angeles County Sheriff’s Department, and published in the October 1998 edition of The Police Chief indicated that 90% of the officers involved in 348 shootings experienced some type of perceptual disturbance.  Besides vision and hearing distortions, this study also measured distortions in memory and time.  Their results were as follows:


Dr. Alexis Artwohl, author of Surviving Deadly Force Encounters, is doing a more extensive and ongoing study of changes that occur because of high stress or deadly force encounters in law enforcement.  Her study, although not involving as many officers as the LASO study, is much more detailed.  Besides changes in hearing and vision, Dr. Artwohl focuses on changes in thinking, awareness, memory and performance under stress.  She obtained the following results:

In Dr. Artwohl’s study a large part of the reactions have to do with thinking, awareness and memory, which have more to do with how the brain is operating under stress than it does with just the eye and ear.  Remember, the eye, ear and other senses do not have a will of their own, but operate at the directions of both the conscious and unconscious mind – a blink to an object coming at the eye is an instinctive reaction of the unconscious mind, while a directed weapon stare is a reaction of the conscious mind.


 Even in non-stress situations, when something catches our attention we begin to have “selective attention.”  We focus on the object of our attention to the exclusion of other things.  This process involves two steps.  First we become “oriented” toward the event – meaning that we shift our attention toward it and then we “focus” on it or funnel our concentration in on it – again to the exclusion of other things in the sensory environment.


 As we shift our attention toward something, the mind will direct the senses to give it the information it needs in the speed that it needs it.  If whatever we are focusing on begins to create an emotional response, such as a fear, a whole cascade of responses happen that amplify the sense, thought and behavioral processes.


An Illustration – Vision

 According to Dr. Paul Michels, an optometrist who specializes in visual perception under low light, the eye, in its normal operating mode, sees clearly only that which is directly in front of our focus – anything that is more than five degrees off center becomes very difficult to see until it gets so removed from our central focus that it fades from our peripheral vision.  If you want to check this out, hold this page up in front of you.  While continuing to look straight ahead, (where the page was) move the page away from your central focus.   As you move the page beyond the five-degree range you will notice that the writing becomes just lines.  You won’t have to move it far before the lines are not even recognizable as writing.  This is important!  Even though you can’t tell that the lines are writing, you still know it is writing.  There are many reasons for this including contextual clues, such as knowing that it looks like lines on a page.