Objective assessment of nap as a method to improve cognitive performance using a bio-mathematical model

Abstract

Introduction: Strategic naps are considered as efficacious means of maintaining performance and reducing the individual’s sleep debt. It can reduce subjective feelings of fatigue and improve performance and alertness. However, literature is scant on assessment of naps and associated cognitive performance in the Indian military aviation scenario. This study is an attempt to assess the nap duration and its objective assessment on gain in performance, if any. Material and Methods: In this cross-sectional observational study, sleep data were collected from 23 aviation personnel in a military flying base using actigraphy device. The actigraphic data were then fed into a software called fatigue avoidance scheduling tool. The nap duration and its effect on cognitive parameters were analyzed. Results: About 65.2% of the participant were found to be Day-Time Habitual Nappers. Of the 50 Naps logged by these participants, 11 (22%) naps were less than 30 min, 14 (28%) were between 30 and 60 min, 15 (30%) were between 60 and 120 min, and only 10 (20%) were above 120 min. Post-nap gain in the effectiveness and other cognitive parameters was found to be different in different cognitive domains. Conclusion: Naps more than 30 min had the optimal efficiency. The nap-induced gain in the task effectiveness and cognitive performance was confirmed. While the performance enhancement was significant for the naps more than 30 min, naps more than 60 min did not have any added advantages.