Reduction in EEG Theta Power as a Potential Marker for Spatial Disorientation during Flight

Abstract

Abstract Spatial disorientation (SD) during flight is a common occurrence, manifesting when an aircrew's perception conflicts with the aircraft's actual motion, attitude, or position. A prevalent form of SD is the somatogyral illusion, which is elicited by constant speed rotation, causing a false perception of motion in the opposite direction once rotation ceases. This research aimed to investigate brain activity changes during exposure to this illusion. We designed a unique experimental setup where twenty-three volunteers were exposed to the somatogyral illusion while seated on a Barany (rotating) chair. The study employed EEG and eye-tracking glasses to monitor brain activity and eye movements, respectively. Subjects were isolated from external stimuli, promoting effective illusion induction. Participants reported their perceived motion direction using a joystick, allowing us to compare a reference condition to one with the illusion present. Results indicated a significant decrease (52%) in theta power (4–8 Hz) over left frontal channels during the illusion, complemented by the occurrence of nystagmus in 72% of trials. These findings align with previous studies linking SD and theta band changes, suggesting implications for EEG-based identification of SD in flight.