The high-quality, mentally tough Soldiers the Army requires must operate in small, highly effective teams in far-forward environments, often without access to air support, evacuation and other capabilities. They must remain lethal for extended periods of time otherwise they risk becoming a liability to themselves and their teammates.
One of the most critical components of a maximized human performance is sleep—but fighting cannot stop to accommodate a full night’s sleep. Stimulants like caffeine are effective to a certain point but there is no substitute for sleep. Soldiers need a tool that allows them to plan their sleep to ensure peak performance during certain periods. They need a tool that helps optimize caffeine use to provide the maximum boost possible. They need a tool that is fast, easy and convenient.
Army scientists hope the 2B-Alert is that tool. Initially conceived of at WRAIR, 2B-Alert utilizes WRAIR’s laboratory data and an algorithm developed by Biotechnology High Performance Computing Software Applications Institute to build a predictive model of performance. Building off initial success, researchers began working on a more individualized version of the model, which is currently in advanced development with the U.S. Army Medical Materiel Development Activity.
Sleep models and scheduling tools have existed in one form or the other for decades—especially in the transportation industry. These statistical models predict changes in performance by analyzing sleep and wakefulness patterns as well as circadian rhythms and have helped influence regulations limiting how long those employees can be on the job.
2B-Alert is different because it provides personalized data as well as recommendations regarding when to utilize caffeine. The app collects data from wearable actigraphs—devices that strap to a subject’s wrist and collect data about sleep and activity—and utilizes the psychomotor vigilance test—a gold standard laboratory test for measuring reaction time where the subject clicks a button as soon as a cue comes on screen.
“There are people who can have the same amount of sleep loss but feel different changes in performance. If you and I both slept five hours tonight and today you are doing great but I am not, the app will capture that and report that I am vulnerable to performance loss. If I know that I want peak performance tomorrow, the model will recommend to me how much caffeine to take or when to go to sleep,” says Dr. Tracy Jill Doty, WRAIR’s lead scientist evaluating the application.
A quick, three to five minute PVT performed during sleep loss can accurately model the relationship between sleep and performance. Most interestingly, PVT scores can be compared to blood alcohol level, allowing for scientists to correlate a certain amount of sleep loss to a certain blood alcohol content. For example, researchers were able to identify that the 40% decline in cognitive functioning after sleeping less than five hours per day for five days is equivalent to operating with a BAC of .06.
Whether you feel it or not, sleep loss takes a physical and emotional toll on your body—research has indicated direct impacts on emotion and mood, appetite, fat deposition, cognitive performance, learning and the immune system. Though the depth of that impact is broadly variable from person to person, evidence suggests it is dose dependent—the less sleep one gets, the more profound the negative consequences. Furthermore, after periods of intense energy expenditure, sufficient sleep is vital to full recovery.
Approximately one in three Americans doesn't reach the National Sleep Foundation’s recommendation for 7-9 hours of sleep, costing the economy approximately $411 billion a year due to lower productivity and higher risk of mortality. The problem is particularly pronounced in the military, where 62% of Soldiers get less than six hours of sleep a night. For decades, a culture that prioritized operating on restricted sleep flourished, considering a full night’s sleep a sign of weakness or cowardice. In fact, it was believed that Soldiers operating in high-tempo, operational environments could operate effectively on just four hours of sleep. On the medical side, one study found that 51 percent of active duty U.S. Army, Air Force and Navy personnel have obstructive sleep apnea and another 24 percent suffer from insomnia. Perhaps most concerning is that every behavioral health issue listed in the Diagnostic and Statistical Manual of Mental Disorders, the diagnostic tool published by the American Psychiatric Association, has a sleep component to it.
To further complicate matters, simply setting aside enough time for sleep is not sufficient to gain the full restorative effect—the sleep must be of sufficient quality as well. Factors like an overstimulating environment (superfluous lights, sounds, etc) or stress can limit sleep quality.
These performance decrements have significant, negative impacts on military readiness. Irrespective of military occupational specialty, decreased reaction times, cognitive performance and physical fitness can endanger lives and mission success by limiting the ability of Soldiers to accurately identify and respond to threats in unfamiliar or unfriendly environments. Restricted learning capacity can require extra training, costing time and money. The altered appetite and physiology can impact the ability to pass required physical fitness tests—a concern that could make itself felt in a meaningful way as the new, more stringent Army Combat Fitness Test looms. Soldiers with compromised immune systems will get sick more frequently and take longer to recover. During a full-scale conflict with a near-peer competitor, these impacts, felt across the entire force, could be decisive.
Indeed, the impact of sleep deprivation has already made itself felt. Approximately 43,000 Soldiers are non-deployable every day and 8 million duty days are limited or lost due to preventable injury. Several non-combat incidents resulting in casualties have been blamed in part on sleep deprivation, including the recent spate of deadly accidents in the Pacific.
Americans’ preferred solution is caffeine, often in the form of coffee, tea or soda. Considered the gold-standard and preferred over other stimulants, caffeine does have its drawbacks. Data from a WRAIR study suggests that during chronic sleep restriction, a consistent amount of caffeine each day will eventually be ineffective and result in the same level of performance as if one had never taken it at all—it may even impede the body’s ability to recover. A separate WRAIR study found that alternatives like energy drinks, which are widely used throughout the military, have been correlated to long-term behavioral health concerns.
In other words, while caffeine can be effective for a short-term burst, a more targeted and judicious approach is required for long-term benefits.
WRAIR has operated in the sleep field for decades, making significant, world-changing discoveries. They developed the original actigraphy devices, now the cornerstone of modern smart watch technology, to reliably quantify sleep; they pioneered functional brain imaging techniques, allowing for greater understanding how the brain is impacted by sleep and they discovered the phenomenon of sleep banking, where extended sleep prior to a period of sleep restriction can blunt the decline in performance and shorten recovery time. Furthermore, their research has shifted policy in numerous organizations including the Federal Aviation Administration’s sleep standards for pilots and the Army’s Performance Triad, which aims to optimize Soldier sleep, activity, and nutrition to improve readiness and lethality.
WRAIR scientists collect the data they need in many different ways. In addition to a broad array of preclinical laboratory efforts, they operate the Sleep Research Center, the DOD’s premier sleep center with eight beds dedicated solely to human research. They also have deployed to places like Iraq, Afghanistan or Korea as part of Mental Health Advisory Teams and embedded with Soldiers during training exercises to collect on-the-ground data to inform future research as well as unit Commanders.
The app, currently available, has both a generalized model and an individualized model. The generalized model, available through their website, utilizes WRAIR data collected from laboratory testing to build an average whose recommendations will be approximately 80% effective. The individualized model, available through the application, utilizes personalized sleep data and PVTs to provide more accurate, personalized data.
Scientists at WRAIR, BHSAI and USAMMDA have high hopes for the application. Already successful in laboratory and personal settings, they would ultimately like to incorporate alternatives to the PVT that are non-invasive and unobstrusive using metrics like screen usage or eye movement. They would also like to evaluate other sleep influencers—including food, alcohol or prescription medication—within the application. “The beautiful thing about the model is that you can continue to refine it. You can imagine an environment where you have this phone, you do a few PVTs and the model learns you. At the same time, it also is collecting [biometric] data and matching those to your PVT data so that at some point you do not even have to do a PVT—it just goes off of your wearables,” says Doty.
Currently, there is no perfect substitute for a good night’s sleep. But for Soldiers operating with limited sleep schedules, for whom knowledge retention, reaction time, spatial awareness and general health are particularly critical, who are expected to operate at peak performance in austere environments with limited medical, logistical and aerial support for extended periods of time, the efficient and judicious use of stimulants is critical.
Innovations like the 2B-Alert application allow for rapid, personalized sleep recommendations to support the far-forward Soldier and minimize the danger of sleep loss to themselves and their teammates, making them a critical addition to our arsenal. Working with other WRAIR discoveries or innovations like caffeine-laced chewing gum, sleep banking and more, they can be decisive on the battlefield.