Short-term vestibular responses to repeated rotations in pilots

[corrected] It has been suggested that vestibular function in pilots differs from that of non-pilots.

Short-term vestibular responses to repeated rotations were explored in pilots and non-pilots using a rotating chair. Vestibulo-ocular reflex tests were done in 30 pilots (VOR-P) and 30 non-pilots (VOR-NP) at rotation frequencies of 0.01, 0.02,0.04, 0.08, 0.16, and 0.32 Hz. In a separate experiment, VOR tests were done at 0.16 Hz before and after four successive velocity-step tests in twenty-five pilots (STEP-P) and their results were compared with the results of twenty-five non-pilots (STEP-NP) who were studied earlier.

VOR-P exhibited normal VOR gains (mean values 0.47, 0.57, 0.63, 0.69, 0.67, and 0.74, respectively, for the frequencies listed above) compared with those of VOR-NP (0.48, 0.54, 0.59, 0.67, 0.72, and 0.79). VOR gain at 0.16 Hz showed little change in STEP-P (0.64 +/- 0.04 to 0.58 +/- 0.032), while it increased in STEP-NP (0.59 +/- 0.03 to 0.78 +/- 0.06).

VOR gain may be a useful measurement for differentiating pilots' vestibular function from that of non-pilots. After-rotary VOR may be suppressed in pilots.