Cognitive benefits of sleep and their loss due to sleep deprivation

When Nobel laureate Otto Loewi discovered the chemical basis of neurotransmission in 1921, he attributed his experimental design to an insight he made during sleep.¹ In recent years, scientific discoveries have begun to empirically validate the hypothetical role of sleep in cognitive processes such as insight formation and memory consolidation. Yet these new and important scientific findings—that sleep benefits cognition—have gained little attention in the debates over regulating resident work hours.

In this article, I aim to achieve three goals: First, I will show that sleep deprivation causes two independent negative consequences to cognition: a detriment and a loss of benefit; I will explain this distinction. Second, I will briefly review evidence supporting sleep’s benefits for cognition. Finally, I will argue that these benefits of sleep for cognition provide novel reasons why depriving residents of sleep is inconsistent with our ethical standards and educational goals for medical training. In this final section, I will also argue against the assertion that residents should use performance-enhancing medications to overcome the effects of sleep deprivation.

Sleep loss: Distinguishing detriments from loss of benefits

Sleep loss causes profound impairments in cognitive and behavioral performance. For example, in a prospective, randomized study looking at the effects of sleep deprivation in residency training, interns working a “traditional schedule” made 36% more serious medical errors compared with interns under an “intervention schedule” that included more sleep.² Another study demonstrated that traditional-schedule interns had more than twice the rate of attentional failures when compared with the intervention-schedule interns.³ Taken together, these studies demonstrate that sleep-deprived house staff make a …