From the way we perceive, recognize, and respond to a threat to how that stress affects our performance, there is a science behind every human reaction and perception. To better understand optimum training and tactics, it is important to understand the science behind human performance as well.

It is beneficial for instructors to know how the brain processes and uses information. This information is what directs the body to perform in a certain way. By studying these processes even at surface level, the complexity of decision making in policework becomes apparent. It can help foster better training habits to recognize how the mind works with the body.


When we get information from the environment through sight, sound, etc., our minds process it. Both the information and the interpretation of it are the two vital parts of perception.

Perception can be altered if the information is of a lower quality – such as an excess of or lack of light or sound from the environment. If your focus of attention is elsewhere or non-existent, it interferes with perception. Additionally, arousal can heighten your ability to perceive.

Schema is another possible obstacle to perception. Schemas are models used to organize knowledge and categorize certain things and situations. This is what allows us to recognize events quickly in the world. For example, imagine a subject drawing a weapon. Some may imagine a person pulling a gun from the hip area. However, there are other objects besides a gun that can be removed from the hip area. A phone or a wallet, for example.

Reaction and Response Time

When a person hears and/or sees a stimulus, it takes time for the brain to process and interpret that information before an action is performed. You must also account for the time it takes to move to complete that action. Many things can lengthen the time between perception and response.

This process is vital for officers and instructors to understand, as it relates to the commonly used “split-second decision making” described in policework.  It is also where decision training comes into play and considering what types of training foster correct decisions and fast responses.

Think of how parts of many firearms training courses work. A buzzer goes off, and the officer shoots a target. This is a great example of a stimulus eliciting a response; however, it is not the pattern that officer involved shootings follow. This is where officers should be trained in evaluating before responding – not just relying on stimuli.

Stress and Arousal

Stress is different for everyone. Sometimes it comes from chaos, sometimes from an event perceived as frightening. It tends to happen to officers particularly when their safety is at stake. Stress increases your heart rate, blood pressure, and breathing rate while also making you more tense.

Arousal relates more to heightened senses and readiness to act. You have likely heard of the “fight, flight, freeze, fawn” responses – these are initiated by arousal. Arousal can increase performance to a certain point – and it depends on whether the task is cognitive-based or strength-based. Having lower arousal is better during a cognitive task such as chess, but higher is better for a strength or endurance task like wrestling.

When keeping stress and arousal in mind – imagine how they may affect an officer during a tense situation.

Human Factors in Force Encounters

Due to the high importance of this topic, VirTra developed a 7-hour NCP-certified course based on groundbreaking research such as the work done by Force Science. “Human Factors in Force Encounters” includes in-depth information pertaining to the information above while fostering decision making by providing 7 modules of drills to be completed in the VirTra simulator. It intertwines classroom learning and practice in a simulated environment.

If you are interested in starting your simulation training journey with VirTra, contact a specialist.

Starting in 2020, VirTra partnered with Critical Incident Review (CIR) to provide law enforcement officers with opportunities to attend specific CIR classes for free. VirTra understands that modern training is critical and is working to deliver it to as many individuals as possible! The course, “Enhanced Force Investigations; Applying Science, Evidence-Based Methods & the Cognitive Interview”, occurs multiple times each year in a variety of states, in order to spread it to departments nationwide.

To help spread awareness and training for all, VirTra is sponsoring two seats per class. Meaning, officers who apply are in the running for free tuition! For the remainder of 2021, classes with sponsorship registration still open are:

  • October 12th – 14th, Maineville, Ohio
  • November 9th – 11th, Tempe, Arizona

This course covers Human Factors and limitations, the use of “video evidence”, the highly effective cognitive interview technique, and employing an investigative analysis of an officer-involved in a critical incident. Officers who successfully complete this course will earn a certification in the development of Enhanced Force Investigations and the Cognitive Interviewing Process.

Learn more about CIR’s class and VirTra’s sponsorship in the video below.

If you are a law enforcement officer and can benefit from this form of training, please click here to apply for an upcoming sponsorship.

Everyone has experienced a stressful situation before, even those outside of the law enforcement field. Stress can be caused by a verbal argument, a heavy workload at your job or even a traffic jam on the way home. Stress and its influence on arousal are two factors that can greatly influence your performance on the job, particularly as a law enforcement officer during a force encounter.

Both stress and arousal can help or hinder various aspects of performance, but the two are not the same. Stress can occur when the perceived demands of an event exceed one’s perceived ability to meet those demands. Stress is expressed physical arousal in the form of increased heart rate, blood pressure and breathing patterns. Too much stress can limit one’s ability to recall an event.

The purpose of arousal, is the act of stimulating readiness. Your senses become “prepared” to the point of perception. It affects the regulation of consciousness, attention and alertness. In fact, the common “fight, flight and freeze” responses are initiated by arousal.

The Yerkes-Dodson Law

The Yerkes-Dodson Law specifically relates to arousal and is characterized by its “Inverted U” graph. This law “suggests that there is a relationship between performance and arousal” (Cherry, 2020). Lower arousal is better for cognitive tasks, while high arousal is better for strength and endurance-related events. Essentially, arousal can improve performance, but if arousal climbs too high, it can begin to hinder it. As the graph above shows, there is an apex where peak performance can be achieved.

So how does this relate back to the law enforcement field? It is important to know how stress affects you personally and how it can compound with arousal, and the best way to find out is during training sessions. Higher arousal can affect perception; it allows people to focus on pieces of events that the brain deems important to survival, but it does so at the detriment to other parts of the event. By practicing in a VirTra police training simulator, you can learn how stress and arousal contribute to your memory of events and performance. Training tools that induce stress such as the Threat-Fire® can provide stress and consequences within a safe environment, letting you learn to work through situations under pressure.

To learn more about human factors, customers have free access to the Human Factors in Force Encounters V-VICTA™ curriculum. This IADLEST-certified course includes a lesson plan, slide show presentation, course materials and more to teach officers the science behind our reactions during force encounters. Additionally, the content was authored by not only VirTra’s in-house subject matter experts, but based on the ground breaking work of Force Science Institute’s Executive Director and Co-Founder Dr. William Lewinsky.

To learn how to get this content, please contact a product specialist.


Cherry, K. (2020, May 10). The Yerkes-Dodson Law and Performance. Retrieved from Very Well Mind:

Law Enforcement Events Being Captured

There is a very concerned societal focus on police use of force encounters. These events are increasingly being captured on law enforcement body cameras and then quickly distributed for all to see. The nature of being human makes the viewing of any type of violence hard to watch. It invokes an emotional response that is very visceral and compelling. It has created a “call to action” that has many saying that we have to do something…anything.

Evaluating Events of Law Enforcement Officers

To properly evaluate these events, they have to be looked at not only within the legal framework that ties our society together but also from the human factors that critically influence how these events play out. There are organizations like the Force Science Institute (Dr. Bill Lewinski) and researchers like Tom Hontz (deceased), Dr. Joel Suss, Dr. Roger Enoka, Christopher Heim, and David Blake that have critically looked at many of these factors. These researchers have brought to light many aspects of what we can really expect from human beings under these difficult parameters.

Use of Force Simulator Training Events

VirTra has produced a new series of use of force training simulator events called “Human Factors in Force Encounters” that takes some of this vital research to provide a dynamic and interactive experience that can demonstrate and teach these concepts. These training events are not a “scenario” as typically represented in some training simulators – they are much more. They come complete with a comprehensive curriculum to assist agencies in teaching and using the training events. They provide an immersive and gripping experience that provides an insight to citizens, police leaders/trainers, community leader, and lawmakers.

VirTra believes that these Human Factors in Force Encounters training events are pivotal for building a better understanding for all parties involved. In this spirit, VirTra is providing these training events to all existing customers that can run these events at no cost.

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