PaperPMID 15018267

Predictions from the three-process model of alertness

Venue listed2004Added Nov 9, 2026

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Authors: T. Åkerstedt, S. Folkard, C. Portin

Aviat Space Environ Med 2004;75(3 Suppl):A75–A83

TL;DR

Computer model using work-hour and/or sleep timing; circadian + homeostatic components summed to predicted subjective alertness (1–21 scale) with predictions of psychomotor performance, impairment-risk thresholds, sleep latency and awakening time. In use for navy, airline and railway schedule evaluation.

  • Form factor: software (sleep/schedule input; wrist actigraphy optional)

Abstract

This paper summarizes a computer model for predicting alertness/performance in daily life. The model uses the timing of work hours (and/or sleep hours) as input and uses both a circadian and a homeostatic component (amount of prior wake and amount of prior sleep) that are summed to yield predicted subjective alertness (on a scale between 1 and 21). The model also includes prediction of psychomotor performance on various tasks, an identification of levels at which the risk of performance/alertness impairment start, as well as a prediction of sleep latency and time of awakening from sleep. The model is currently being used to evaluate work/rest schedules for navy, airline and railway applications. It is also used for teaching sleep/wake regulation and for generating research hypotheses.

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Tasks & signals

Tasks

Stress

Keywords

FatigueBiomathematical Fatigue ModelThree Process ModelKSS

How it works

How Method works: Setup → Method → TargetSetup: Signals (work/sleep timing); Form factor (software (sleep/schedule input; wrist actigraphy optional)). Method: Method. Target: Stress.SetupSignals: work/sleep timingSignalswork/sleep timingForm factor: software (sleep/schedule input; wrist actigraphy optional)Form factorsoftware (sleep/schedule input; wrist…MethodMethodTargetStressStress

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Åkerstedt, T., Folkard, S., & Portin, C. (2004). Predictions from the three-process model of alertness. Aviat Space Environ Med 2004. https://pubmed.ncbi.nlm.nih.gov/15018267/
Åkerstedt, T., S. Folkard, and C. Portin. 2004. "Predictions from the three-process model of alertness." Aviat Space Environ Med 2004. https://pubmed.ncbi.nlm.nih.gov/15018267/.
Åkerstedt, T., Folkard, S. and Portin, C. (2004) 'Predictions from the three-process model of alertness', Aviat Space Environ Med 2004. Available at: https://pubmed.ncbi.nlm.nih.gov/15018267/
Åkerstedt, T., et al. "Predictions from the three-process model of alertness." Aviat Space Environ Med 2004, 2004. https://pubmed.ncbi.nlm.nih.gov/15018267/.
T. Åkerstedt, S. Folkard, and C. Portin, "Predictions from the three-process model of alertness," Aviat Space Environ Med 2004, 2004, [Online]. Available: https://pubmed.ncbi.nlm.nih.gov/15018267/.
@article{akerstedt2004predictions,
  title         = {{Predictions from the three-process model of alertness}},
  author        = {Åkerstedt, T. and Folkard, S. and Portin, C.},
  year          = {2004},
  journal       = {Aviat Space Environ Med 2004},
  url           = {https://pubmed.ncbi.nlm.nih.gov/15018267/}
}

Source metadata: 2004

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