Reduction in EEG theta power as a potential marker for spatial disorientation during flight

Area of Science:

• Neuroscience
• Aerospace Medicine
• Human Factors Engineering

Background:

• Spatial disorientation (SD) is a critical risk in aviation, impairing pilot perception of motion and aircraft attitude.
• The somatogyral illusion, a common form of SD, arises from rotational stimuli and leads to inaccurate motion perception upon cessation of rotation.
• Understanding the neural correlates of SD is crucial for developing effective countermeasures and improving flight safety.

Purpose of the Study:

• To investigate the neurophysiological changes associated with the somatogyral illusion under simulated flight conditions.
• To explore the utility of electroencephalogram (EEG) and eye-tracking in identifying and quantifying SD.
• To provide insights into managing somatogyral illusions for enhanced pilot safety.

Main Methods:

• Utilized a Barany chair to simulate rotational stimuli, inducing somatogyral illusions in 23 volunteers isolated from external cues.
• Employed electroencephalogram (EEG) to monitor brain activity and eye-tracking glasses to record eye movements.
• Collected subjective motion perception data via joystick input for comparison with objective physiological measures.

Main Results:

• A significant 34% decrease in theta power (4-7.5 Hz) was observed over the left frontal region during the somatogyral illusion.
• Nystagmus, an involuntary eye movement, occurred in 72% of the experimental trials.
• Results demonstrate a correlation between SD, theta band activity changes, and specific eye movement patterns.

Conclusions:

• Findings support the link between spatial disorientation and alterations in theta band brain activity.
• The study suggests the potential for EEG-based systems to detect SD in real-time flight scenarios.
• Further research can leverage these findings to develop advanced SD detection and mitigation strategies for aviation.