Table 1.
Mean ± SD thresholds for each condition of each vestibular experiment
| Earth horizontal/head horizontal | Earth horizontal/head vertical | Earth vertical/head horizontal | Earth vertical/head vertical | |
|---|---|---|---|---|
| Vestibular heading | ||||
| Two-interval | 6.01 ± 2.31° | 15.97 ± 4.60° | 12.86 ± 3.88° | 8.93 ± 3.70° |
| Equivalent one-interval threshold | 4.25 ± 1.63° | 11.29 ± 3.25° | 9.09 ± 2.74° | 6.31 ± 2.62° |
| Coarse discrimination (one-interval) | 0.063 ± 0.025 m/s2 | 0.110 ± 0.029 m/s2 | 0.093 ± 0.023 m/s2 | 0.097 ± 0.034 m/s2 |
| Amplitude discrimination | ||||
| Two-interval | 0.126 ± 0.071 m/s2 | 0.124 ± 0.059 m/s2 | 0.104 ± 0.054 m/s2 | 0.117 ± 0.078 m/s2 |
| Equivalent one-interval threshold | 0.089 ± 0.05 m/s2 | 0.088 ± 0.042 m/s2 | 0.074 ± 0.038 m/s2 | 0.083 ± 0.055 m/s2 |
Thresholds correspond to the 84% correct level for each task. Note that heading and amplitude discrimination thresholds were obtained from two-interval tasks (Fig. 3). To facilitate comparison across tasks, these thresholds have also been expressed as equivalent one-interval thresholds (computed by dividing by
). This is because, in a single-interval task, the 84% correct threshold is equal to the SD of the underlying estimator, whereas in a two-interval task, it is times the standard deviation of the underlying estimator (Ernst and Banks, 2002).
