Circadian Rhythms, Sleep Deprivation, and Human Performance - Progress in Molecular Biology and Translational Science - page 155

CHAPTER SEVEN

Circadian Rhythms, Sleep
Deprivation, and Human
Performance

Namni Goel * , Mathias Basner * , Hengyi Rao * , †

, David F. Dinge s *
* Division of Sleep and Chronobiology, Department of Psychiatry, Perelman School of Medicine, University of
Pennsylvania, Philadelphia, Pennsylvania, USA
† Department of Neurology, Center for Functional Neuroimaging, Perelman School of Medicine, University of
Pennsylvania, Philadelphia, Pennsylvania, USA

Contents
1. Introduction 156

2. Sleep - Wake and Circadian Regulation: Two-Process Model 157

3. Circadian Rhythms of Performance 162

3.1 Subjective measures of sleepiness and alertness 162

3.2 Objective measures of cognitive performance 162

3.3 Masking factors 163

4. Protocols to Assess Circadian Variation in Neurobehavioral Functions 164

4.1 Constant routine 164

4.2 Forced desynchrony 165

5. Interindividual Variability in Circadian Rhythms 166

5.1 Chronotype (morningness eveningness) 167

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5.2 Genetics of individual differences in chronotype and circadian rhythms 168

6. Sleep Deprivation and Performance 169

6.1 Phenotypic and genotypic differences in response to sleep deprivation 170

6.2 Neuroimaging of sleep deprivation and circadian variations in brain
metabolism and neural activity 173

7. Conclusions 178

Acknowledgments 178

References 178

Abstract
Much of the current science on, and mathematical modeling of, dynamic changes in
human performance within and between days is dominated by the two-process model
of sleep - wake regulation, which posits a neurobiological drive for sleep that varies
homeostatically (increasing as a saturating exponential during wakefulness and
decreasing in a like manner during sleep), and a circadian process that neurobiologically
modulates both the homeostatic drive for sleep and waking alertness and performance.