The Police Chief, the Professional Voice of Law Enforcement
Advanced Search
September 2016HomeSite MapContact UsFAQsSubscribe/Renew/UpdateIACP

Current Issue
Search Archives
Web-Only Articles
About Police Chief
Law Enforcement Jobs
buyers Your Oppinion

Back to Archives | Back to August 2009 Contents 

Officer Performance in High-Stress Situations: Considerations for Technology Design

By Moin Rahman, Principal Scientist, Enterprise Mobility Solutions, Motorola, Plantation, Florida

fficer safety is of utmost importance for law enforcement executives. Although training can help decrease the number of injuries and deaths, advancements in technology can also prove highly beneficial. Communication tools can enable quick results, but these technologies and features must evolve without adding user complexity. A new field of research is driving innovation and helping to revolutionize the future of public safety. The science behind this innovation is the key to ensuring that men and women stay safe on the streets.

Police officers and other first responders have recounted that when they are thrust into situations where life is threatened and death is possible at any moment, every second is vivified. These situations create experiences that range from hyperclarity to the perceived slowing down of time.

A new area of research that studies human performance under extreme duress has been pioneered by Motorola’s scientists at the Design-Integration Human Factors Laboratories in Plantation, Florida. This area of scientific inquiry has been named High-Velocity Human Factors (HVHF).

When designing communications technology for police officers, firefighters, and other emergency responders, it is not enough merely to understand human performance under little or no stress conditions—what scientists call “equilibrium.” It is equally, if not more, important for designers to understand the ability of a police officer to think, act, and react in those “moments of terror” when stakes are high and threats to life and limb are imminent. More than ever, it is in those circumstances that technology needs to be second nature to the user.

Brief Overview of HVHF

When faced with a high-stress situation, most people are unsurprised when their hearts start pounding or their palms get sweaty. However, most would probably be surprised to discover that they might find it difficult to form coherent sentences or even to speak at all when under stress. And they might even be a little offended to know that their thought patterns under stress likely resemble a reptile’s more than a human’s.

A scientific term often used to describe a high-stress situation is nonequilibrium. Nonequilibrium is a state in which public safety responders—including police, firefighters, and other emergency personnel—find themselves more than most.

The nonequilibrium state in the public safety arena can perhaps best be summed up in the words written by stress researchers Eduardo Salas and James Driskell more than a decade ago: “Emergency or crisis conditions occur suddenly and often unexpectedly, operators must make critical decisions under extreme stress, and the consequences of poor performance are immediate and catastrophic.”1

Surprisingly, most technology, even in the public safety arena, has received insufficient attention to account for an individual’s response in nonequilibrium situations. Instead, it has been designed based on research on human perceptions, cognitions, and reactions that occur mostly under normal or equilibrium conditions. In fact, an entire area of research, called human-factors sciences, is focused on how to create technology that a “human agent” can operate easily under such equilibrium conditions.

But in the public safety community, first responders often need to operate technology under conditions that are anything but stable or normal. And their responses in these high-stress, nonequilibrium situations can affect their ability to effectively operate the technology they use every day. These nonequilibrium situations, encountered by special weapons and tactics (SWAT) officers or firefighters battling a raging fire are volatile, uncertain, complex, and ambiguous and unfold at a rapid pace, causing severe physical and cognitive stress, including emotional arousal. In these nonequilibrium conditions, particularly due to time stress, action is more important than deliberation, responding is to be prioritized over consideration, and deciding takes precedence over planning. On the other hand, if responders had no time stress, with all the time in the world at their disposal, they would have the luxury to deliberate endlessly, consider all viable modes of action, and choose the best and meticulously planned-out action to obtain the best outcome.

The study of HVHF goes over and beyond traditional human factors, as it is specifically concerned with adapting technology to the human agent whose normal capacities have been diminished, not due simply to multiple tasks or workload but to emotional stressors engendered by high stakes. Emotional arousal is an evolutionarily hardwired response to enable a human to make a timely decision that will prevent catastrophic outcomes. However, it should be noted that if emotional arousal is suboptimal—that is, too high or too low—decision making, too, will be suboptimal, because emotion modulates cognition either for better or for worse.

Impact of Stress on Human Performance

In a high-stress situation, individuals actually can lose the ability to use some portions of their brain. In nonstress situations, humans generally use three levels of brain activity: the primitive or reptilian brain (in charge of survival, sustenance, and reproduction), the mammalian brain (the type of activity humans share with other intelligent mammals), and the neomammalian brain (activity that allows humans to complete more complex tasks than other mammals can, such as calculus equations or music composition). Many high-stress situations lead to so-called regressive behavior, where the two higher-level types of brain activity are almost completely incapacitated. This causes humans to respond very primitively—much like reptiles.

To compensate for the loss of high-level brain activity in high-stress situations, individuals automatically cut off as much information as possible and process only the most relevant information, if they can get it. For instance, individuals in high-stress situations might experience something called “cognitive tunneling,” where a person might see only certain things that are relevant to the perceived threat, to the exclusion of all others.

“The human body is marvelously designed to deal with both threat and challenge. However, while our mechanisms, like the effects of adrenaline, are in place, they can become excessive and impair performance,” says Dr. Michael Asken, a clinical and police psychologist and the author of MindSighting: Mental Toughness Skills for Police Officers in High Stress Situations.2

Laws of HVHF

So how does this relate to the use of technology? Officers in high-stress situations may have trouble, for instance, processing all of the information normally presented on the dashboard display in their police cruisers. Or they may have trouble performing operations that require several steps.

Ideally, technology can be designed to account for such limitations during times of stress. For instance, in the future, a police cruiser might have a digital dashboard that would suppress irrelevant information, such as miles traveled, during a police chase and would instead magnify information such as speed or mapping capabilities to facilitate response.

This example epitomizes the first of the “seven laws” of HVHF that have been prescribed to guide the design of mission-critical technology and to accommodate individuals performing under stress. The seven laws are as follows:

  • Law of Relevance: Provide only information that is relevant to the event and can be used to diagnose and resolve the situation.

  • Law of Acceptance: Provide information in a format that can be processed by human agents given their diminished cognitive capacities due to emotional arousal.

  • Law of Transparency: Technology should not become a barrier to information that can be directly perceived in the immediate environment.

  • Law of Clairvoyance: Technology, where possible, should assist human agents to predict the immediate future course of an event.

  • Law of Absoluteness: Critical functions, such as emergency call placement, should have their own dedicated control elements that are accessible and operable in an instant.

  • Law of Intelligence: Technology should be smart enough to take over operations when agents are overloaded with other, more important tasks.

  • Law of Reliance: Technology should be fail-safe and foolproof and should accommodate stress-induced human error.

Second-Nature Product Design

Motorola has embraced design as a key differentiator for over 30 years. Motorola was the first to locate the emergency button on its radios at the bottom of the antenna, making it easy for a police officer to find it without even looking down in an emergency. Other key design features include an angled knob that is easier to operate with a gloved hand and the angled “bump” on the side of the radio for easier grip.

Designers of public safety radios need to ensure that buttons controlling the most critical functions are highly accessible for public safety users. “Volume, push-to-talk, and channel controls are three of the most important features of a radio,” says Mark Palmer, design integration manager of Human Factors Design Research and User Interface Design at Motorola. “That means that under high-stress situations, individuals should not even have to think about how to access them.”

Need for More Research

Seminal HVHF research has gained wide recognition among both scholars and practitioners. Scientific papers in this area have been published at conferences. Since the time these papers were presented, the recognition of the importance of HVHFs has been gaining ground, and more research is being completed in this area. For public safety officials, increased research in the area not only means they will be able to do their jobs more effectively; by extension, it will also help to save more lives.

After all, in the world of the consumer, poor usability simply creates frustration. But in the public safety world, poor design is hazardous or even deadly. Thoughtful, purpose-built, mission-critical design is the first step in making sure first responders are equipped with products and solutions that meet their unique requirements.

Benefits of Intuitive Design

When a mission-critical product is well designed,it delivers various advantages:

  • More effective training: If the product is intuitive, the training required for its use will be minimal.

  • Quicker adoption: Dependable and easy-to-use technology that is comfortable to operate leads to higher and quicker adoption rates.

  • Ownership: If the system is truly second nature, users will take ownership and become the technology's greatest advocates. This not only improves its effectiveness in the field but also bolsters the internal relationships among support staff, such as information technology or radio managers, and frontline officers.

  • Improved mission focus: In an emergency, first responders will instinctively use the technology without hesitating or being distracted by its features.

The goal of HVHF research is to maximize the performance of individuals in high-stress situations, such as those often experienced by public safety users—unpredictable situations that involve high stakes, physical danger, and incomplete information.

“HVHF can be particularly important in law enforcement, because in many ways and especially in dangerous and high-stress situations, police work is reactive in nature, that is, action is in response to a threat,” says Asken. “Police officers do not initiate action until a subject has made a threatening gesture or produced a weapon. Reactive behavior is obviously slower than offensive action. Anything that can aid the quality of an appropriate response is welcome.”3

The author can be contacted via e-mail at ■


1James E. Driskell and Eduardo Salas, eds., Stress and Human Performance (Mahwah, New Jersey: Lawrence Erlbaum Associates, 1996), 3.
2Michael Asken, personal communication with the author.

As a principal scientist at Motorola, Moin Rahman researches human performance, particularly critical and peak-moment performance, in mission-critical domains such as law enforcement and firefighting. Rahman’s ground-breaking research in human factors resulted in his developing the new HVHF paradigm to analyze human cognition and decision making under extreme operational stress.



From The Police Chief, vol. LXXVI, no. 8, August 2009. Copyright held by the International Association of Chiefs of Police, 515 North Washington Street, Alexandria, VA 22314 USA.

The official publication of the International Association of Chiefs of Police.
The online version of the Police Chief Magazine is possible through a grant from the IACP Foundation. To learn more about the IACP Foundation, click here.

All contents Copyright © 2003 - International Association of Chiefs of Police. All Rights Reserved.
Copyright and Trademark Notice | Member and Non-Member Supplied Information | Links Policy

44 Canal Center Plaza, Suite 200, Alexandria, VA USA 22314 phone: 703.836.6767 or 1.800.THE IACP fax: 703.836.4543

Created by Matrix Group International, Inc.®