Visual neglect: occurrence and patterns in pilots in a simulated overnight flight.

Area of Science:

• Human Factors
• Aerospace Medicine
• Cognitive Neuroscience

Background:

• Visual neglect, an unawareness of visual stimuli despite intact vision, was hypothesized to emerge after prolonged wakefulness.
• This study investigated visual perception in military pilots during simulated overnight flights to assess for visual neglect.

Purpose of the Study:

• To explore the occurrence of visual neglect in military pilots under conditions of extended wakefulness.
• To evaluate the relationship between visual performance decrements and operational safety during simulated long-duration flights.

Main Methods:

• Eight military pilots underwent a simulated 12.5-hour overnight flight after 24 hours of continuous wakefulness.
• Participants performed visual perception tasks, responded to light stimuli, and underwent psychomotor vigilance tests.
• Simulator shutdowns and reaction times were recorded, with total wakefulness reaching 26.5 hours.

Main Results:

• Response omissions in visual perception tasks increased significantly starting at 19 hours of continuous wakefulness.
• Observed omissions involved peripheral stimuli and single stimuli in dual-stimulus presentations.
• Simulator shutdowns commenced at 21.5 hours of wakefulness and strongly correlated (r=0.95) with visual task omissions.

Conclusions:

• Significant visual neglect manifested in pilots after 19 hours of continuous wakefulness during simulated flights.
• The onset of visual neglect preceded simulator shutdowns.
• The strong correlation between visual neglect and simulator shutdowns highlights a critical risk factor for flight safety.