EEG activity of aviators during imagery flight training.

OBJECTIVE: Imagery flight training (IFT) is widely used in aviation without neurophysiological evaluation. Electroencephalogram (EEG) during IFT was compared between experienced fighter pilots (FP) and novice pilots (NP). METHODS: Six FP and 9 NP performed imagery right bank, left bank, right roll, and left roll maneuvers. Each task was repeated 5 times in a random order. Instantaneous EEG power was calculated by the intertrial variance method. RESULTS: In FP, 3 waves of event-related desynchronization (ERD) were observed. The third ERD (ERD3) was observed at all the electrode positions except Fp1 which began 0.25 s before the beginning of IFT and reached its peak 0.25 s after the beginning of IFT. In NP, ERD was not related to the start of IFT. The difference in event-related EEG at the peak of ERD3 was not significant between FP and NP. However, the negative change to the peak of ERD3 was significantly larger in FP than in NP. CONCLUSIONS: It is speculated that ERD3 in FP may indicate the activation of cortical areas including visual- and motor-related areas involved in IFT. SIGNIFICANCE: It is speculated that the representation of IFT was programmed in visual- and motor-related cortical areas as an aviator's career advances.

Vector analysis of electrogastrography during motion sickness.

Although the dominant frequency at 3 cpm of electrogastrography (EGG) is reported to shift to a higher frequency during motion sickness (MS), it is unclear whether the normal slow wave (NSW) disappears or not. The authors investigated changes in NSW using vector analysis of EGG. Fourteen subjects were exposed to a Coriolis stimulation to evoke MS. EGG was recorded from two sets of bipolar leads, placed perpendicular to each other representing x and y axes. Trajectories for each frequency were drawn on the x-y plane. The amplitude and phase difference at NSW were compared before, during, and after the stimulus for each subject. In those with a change in phase difference, changes in NSW and tachygastria were negatively correlated (P = -0.048), whereas in those without a change, they were not correlated. This indicated two different kinds of tachygastria due to MS: tachygastria with and without a change in NSW.