2B-Alert Web: An Open-Access Tool for Predicting the Effects of Sleep/Wake Schedules and Caffeine Consumption on Neurobehavioral Performance

Sleep. 2016 Dec 1;39(12):2157-2159. doi: 10.5665/sleep.6318.


Study objectives: Computational tools that predict the effects of daily sleep/wake amounts on neurobehavioral performance are critical components of fatigue management systems, allowing for the identification of periods during which individuals are at increased risk for performance errors. However, none of the existing computational tools is publicly available, and the commercially available tools do not account for the beneficial effects of caffeine on performance, limiting their practical utility. Here, we introduce 2B-Alert Web, an open-access tool for predicting neurobehavioral performance, which accounts for the effects of sleep/wake schedules, time of day, and caffeine consumption, while incorporating the latest scientific findings in sleep restriction, sleep extension, and recovery sleep.

Methods: We combined our validated Unified Model of Performance and our validated caffeine model to form a single, integrated modeling framework instantiated as a Web-enabled tool. 2B-Alert Web allows users to input daily sleep/wake schedules and caffeine consumption (dosage and time) to obtain group-average predictions of neurobehavioral performance based on psychomotor vigilance tasks. 2B-Alert Web is accessible at: https://2b-alert-web.bhsai.org.

Results: The 2B-Alert Web tool allows users to obtain predictions for mean response time, mean reciprocal response time, and number of lapses. The graphing tool allows for simultaneous display of up to seven different sleep/wake and caffeine schedules. The schedules and corresponding predicted outputs can be saved as a Microsoft Excel file; the corresponding plots can be saved as an image file. The schedules and predictions are erased when the user logs off, thereby maintaining privacy and confidentiality.

Conclusions: The publicly accessible 2B-Alert Web tool is available for operators, schedulers, and neurobehavioral scientists as well as the general public to determine the impact of any given sleep/wake schedule, caffeine consumption, and time of day on performance of a group of individuals. This evidence-based tool can be used as a decision aid to design effective work schedules, guide the design of future sleep restriction and caffeine studies, and increase public awareness of the effects of sleep amounts, time of day, and caffeine on alertness.

Keywords: PVT; biomathematical model; caffeine model; prediction tool; sleep schedule.

MeSH terms

  • Attention / drug effects
  • Attention / physiology
  • Awareness / drug effects
  • Awareness / physiology
  • Caffeine / administration & dosage*
  • Caffeine / pharmacology
  • Fatigue / physiopathology
  • Fatigue / psychology
  • Humans
  • Neuropsychological Tests*
  • Patient-Specific Modeling*
  • Psychomotor Performance / drug effects
  • Psychomotor Performance / physiology
  • Reaction Time / drug effects
  • Reaction Time / physiology
  • Sleep Deprivation / diagnosis
  • Sleep Deprivation / physiopathology
  • Sleep Deprivation / psychology
  • Sleep Disorders, Circadian Rhythm / diagnosis*
  • Sleep Disorders, Circadian Rhythm / physiopathology
  • Sleep Disorders, Circadian Rhythm / psychology*
  • Software*
  • User-Computer Interface


  • Caffeine