Impact of the Tach-Psych Effect while under Stress, Duress or Heightened Anxiety!

By: Diana Sorrentino, Ph.D.

Our security, intelligence, investigative and executive protection professionals know very well; from first-hand experience in the field, the physiological and psychological impact of stress, duress, anxiety and the impact of the Tach-Psych effect under these conditions.

Tach-Psych Effect. When you are placed in a situation of extreme stress, duress or heightened anxiety your physiological systems and psychological functioning are significantly impacted in a very predictable manner and will prove debilitating; to the point of your not being able to think clearly or function effectively, if you have not trained your mind and body for these developments.

Under extreme stress, duress or heightened anxiety, the following physiological changes will occur:

  • Loss of fine motor skills. This will typically occur after your heart rate exceeds 115 bpm. The loss of fine motor skills results in you having to rely solely upon your gross motor skills. This will be most notable in your handwriting or anything that requires dexterity. During the period when your heart rate is between 115 bpm and 160 bpm blood flow is redirected away from your extremities so that it will concentrate in your major organs.
  • Tunnel vision. This will result in the loss of up to 70% of your peripheral vision. We have reviewed numerous officer deadly force encounter after action reports where the officer stated that he could count the threads in the buttons on a subject’s polo shirt at a distance of 15’ but he could not see the sights on his pistol.
  • Auditory Occlusion. This will result in your inability to hear what is happening around you. We have reviewed officer deadly force encounter after action reports where the officer stopped shooting during a defensive engagement thinking his gun had malfunctioned because it went Pop when he fired.
  • Impaired or Loss of Your Cognitive Processing. This Psychological condition will typically impact the individual when their heart rate has exceeded 160 bpm. When this happens, the ability to think clearly, rationalize and problem solve is diminished or lost and your Fight or Flight reflex will take over unless you can control your heart rate.
  • Voice.  When an individual is under stress, duress or any level of anxiety the quality of their voice will change and immediately reflect very distinct changes to their voice’s Rate, Tone, Pitch & Volume. You will also be able to hear the stress that will be developing in their voice. Many times, this will be your first indication that the individual will require an intervention.
  • Time Space Distortion. Some individuals have reported that the event took place in extreme slow motion. One officer’s after-action report stated that she could see the bullet and watch it hit her vest when the subject shot at her. Another officer reported that his ejected shell casing looked like someone was throwing beer cans at him when in-fact they were the empty shell casings being ejected from his pistol.

These conditions are recognizable and can be overcome through an understanding of when and how they will impact your ability to function. You are also able to work through them with effective Stress Inoculation training and Psychological preparation.

The impact of these conditions; when experienced, will not be all or nothing. The higher the level of stress, duress or anxiety; the greater the impact. The lower the level of stress, duress or anxiety; the lesser the impact. As such; regardless of the nature and scope of the situation, the Tach-Psych effect will have a direct impact on you.

Give some thought to situations you might have experienced: If you ever had a close call avoiding a motor vehicle accident; been involved in a motor vehicle accident; or were unexpectedly startled or frightened, you have already experienced one or more of the aforementioned elements of the Tach-Psych effect even if only minimally or for a very short period of time.

In order to effectively prepare for the impact of these developments you must begin by accepting the fact that they will impact you.

Additionally; you must work to introduce as much stress as possible into your table top exercises as well as your drills and operational exercises so that you will become comfortable operating in such an environment along with how to work through the conditions. While it is understood that stress inoculation training will never fully duplicate the impact of the physiological and psychological responses which will take place automatically; physical conditioning and a psychological awareness of what to expect will provide you with the skills to operate at peak capacity under the worst of conditions. Simply stated; if you are not physically and mentally prepared to operate under conditions of stress during a Critical Incident or Crisis your effectiveness will be severely compromised.

Your psychological preparedness begins with developing an understanding of how others have been impacted. The suggested texts which follow; which will highlight events and conditions we hope you will never have to encounter, will provide you with real life scenarios and situations of the psychological and physiological conditions experienced by law enforcement, executive protection agents and the military when facing deadly force encounters or combat:

  • On Combat:

          The Psychology and Physiology of Deadly Force Encounters in War & Peace.

Authors: Lt. Col. Dave Grossman (USA ret) & Loren W. Christensen

    • ISBN: 978.0.9649205.4.5


  • Into the Kill Zone:

          A Cop’s Eye View of Deadly Force.

Author: David Klinger

    • ISBN:978.0.7879.8603.2


  • Increasing Resilience in Police and Emergency Personnel:

           Strengthening Your Mental Armor.

Author: Stephanie M. Conn

    • ISBN:978.1.138.64368.0

The better your understanding of how and why your physiological and psychological systems will be adversely impacted when under extreme conditions; as well as how to recognize when these effects are taking place and the means to counteract and work through them, the more effectively you will perform during a crisis or critical incident.

More importantly; the better prepared you are to function under any extreme condition, the less likely you will suffer from any post traumatic disorders when the ordeal has concluded. As you will learn from the aforementioned texts, more frequently than not the aftermath has proven to be more debilitating for the individual than the conditions experienced while in the midst of facing or managing a crisis or critical incident.

Of equal importance; you must openly discuss and review with your colleagues how you and your team will be able to recognize when the physiological and psychological impact of the Tach-Psych effect has begun to impair the functioning of one of your colleagues. Being able to do so will enable you to intervene and remove the individual from the environment until they have had a chance to decompress and recompose. This is of equal importance; if not greater, when working in support of a client’s critical incident and crisis response team since their team members may not be as prepared as your team and may easily fall subject to the effects of stress and anxiety requiring your intervention.

Physical Conditioning. Exercise routines and schedules; which will push you well out-side your comfort zone, will help you prepare to manage a critical incident or crisis. The condition of your physical health and physiological conditioning will have a direct impact on your stamina during an event; as well as your ability to recover after the event.

Whether an individual is a recruit in any of our military basic training programs; or a cadet or midshipman completing a four-year course of study at one of our service academies, the individual is subjected to significant levels of Stress Inoculation so that they will learn that they can and will function effectively under extreme conditions. They function effectively under these extreme conditions because they have learned to work through the stress and any anxiety as it has become familiar territory for them.

Your failure to prepare for the potential impact of stress on your physiological and psychological well-being during a critical incident or crisis will expose you to short and potentially long-term debilitating effects from the stressors you will encounter.

Speaking from my own professional experience; having been shot on two separate occasions, I can attest to the value of this preparation because nothing is more stressful then being involved in a deadly force engagement while on a protective detail.

When the requisite training has been completed and maintained, responses are preprogramed and automatic with the ability to effectively work through the Physiological and Psychological changes brought on through stress, duress or heightened anxiety. This is why our teams train aggressively on a monthly basis; as well as to conduct regular table top exercises, pre-deployment briefings and post-deployment after-action debriefings.

CISM & CISD are proven interventions