Circadian Entrainment in Military Pilots: Transitioning from Day to Night Flights
Abstract
This study assessed the effectiveness of light exposure in transitioning aviation schedules from days tonight's. We hypothesized that a single night of light treatment will delay melatonin onset and improve performance in a simulated flight task. Study participants were military pilots who flew four simulated flights: one baseline daytime flight and three consecutive night flights. Pilots were exposed to four hours of high energy visible (HEV) light (1,000 lux) on the second night but remained in dim light on the first and third nights. Saliva samples for determining melatonin levels were collected every half hour during the three nighttime data collections. Participants also completed questionnaires to include the Bedford Workload Scale and the Karolinska Sleepiness Scale. We tracked each participants circadian rhythm using their melatonin onset profiles over the three nights of the study. Pilot performance in a flight simulator was assessed for each of the three data collection sessions using three flight profiles of progressing difficulty. Results showed an average delay in melatonin onset mean of 1.33 hr (SD = .36 hr). Flight performance over the testing period did not show any significant changes. This study showed that light can be used to effectively delay the onset of melatonin, potentially providing a substantive advantage to personnel who must rapidly transition to new work schedules. Further study is recommended before implementing in operational conditions.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 2022
- Accession Number
- AD1185107
Entities
People
- James S Reily
Organizations
- Naval Postgraduate School