Figure 2.

SVV and torsional position of the eyes during prolonged head tilts. (A) Average SVV during head tilts to the right (red) and left (blue). Each point corresponds with the SVV calculated from responses within 100 trials. The gaps in the data correspond with the first 50 trials in the new head position where SVV estimates were not reliable and were discarded. (B) Average torsional eye position during head tilts to the right (red) and left (blue). As in the SVV plot, each point corresponds with the average ocular torsion within the blocks of 100 trials, and the gap in the data corresponds with the first 50 trials that were discarded. (C) Top and middle: same data as in (A,B) during head tilt aligned in time (instead of trial numbers) show the same pattern of drift in SVV and ocular torsion. The averages are shown for the time points where the SVV data was available from more than half of the subjects. Bottom panel: number of subjects from which data was recorded at each time point during the right and left head tilts. Subjects took different amounts of time to complete the 500 trials. In all panels, the error bars correspond with SEM across subjects.