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Sleep and Performance Research Center

Human Sleep and Cognition Laboratory


Areas of Interest

Sleep deprivation, cognitive performance, operational performance, commercial transportation safety, shift work, sleep and brain injury

Research Scope

Sleep loss causes performance impairments that are dependent on the individual, the task at hand, and a variety of other factors. Sleep loss is often unavoidable, such as for individuals working in shiftwork industries, including commercial transportation, law enforcement, and emergency medicine. These jobs require extended and/or nighttime work hours, which disrupt normal nightly sleep. Mistakes due to fatigue while on the job (or on the commute home) can be both costly and dangerous. By studying the effects of sleep loss on cognitive function and on job performance and safety, we hope to understand how sleep loss causes mistakes so that we can predict and prevent these errors.

Research Focus

In the sleep laboratory environment, we use specially designed cognitive tasks in a carefully controlled setting to measure distinct effects of sleep deprivation. I use a combination of computer-based tests in an effort to identify particular cognitive functions that are most vulnerable or most resilient to the effects of sleep deprivation. Learning how sleep loss affects the brain can reveal how to best protect against sleep loss-related errors.

My laboratory research is translated into a real-world setting with my current field research project, which is focused on sleep and performance in long-haul commercial truck drivers. In this project, we are studying whether increased regulatory flexibility can improve driver rest and alertness. An allowance for drivers to split their required rest time into two shorter breaks, maintaining the total break time, may encourage drivers to nap as needed during a duty period. We will compare driver sleep, alertness, safety, and performance when drivers are operating under the flexible (study-specific) regulations with duty periods in which drivers are operating under the current (standard) regulations.

Staff and Trainees

  • Senada Karmaj (International Placement Student)
  • Junid Naveed Ahmad (UW Medical Student)

Approaches Used

  • Actigraphy
  • Polysomnography
  • Sleep Deprivation
  • Psychomotor Vigilance Test
  • Digit Symbol Substitution Test
  • Karolinska Sleepiness Scale
  • Electronic Duty Logs

Grant Support

  • Federal Motor Carrier Safety Administration
  • Department of Defense