Figure 1.
Methods. A, The coordinate system used for reporting values of θH and θR. B, Expected relationships between head yaw and response direction if response direction is strictly dependent on head yaw (dashed line) or if there is directional specificity of the vestibularly evoked balance response as represented by Equation 1 in Materials and Methods (solid lines). The annotations on the plot refer to Sx/Sy ratios (see Eq. 1) for each line. C, A single-subject example of SVS–force cross-covariance, with the second peak specified by the vertical dotted line. Horizontal dotted lines denote 95% confidence intervals (Halliday et al., 1995). D, A single-subject example of measurement of the onset of body motion in experiment 1, under the 0 cm stance width condition. The solid line is the speed of the C7 marker in the horizontal plane averaged across trials, with time relative to stimulus onset. The horizontal dotted line is the threshold calculated as described in experiment 1 in Materials and Methods. The vertical dotted line marks where C7 speed crossed the threshold level. Lab, Laboratory coordinate system.