Figure 3.

Impact of head jitter on performance when task feedback is provided. (a) Schematic comparing the three viewing conditions. In fixed viewing (left schematic), the scene does not update in response to head jitter, thereby leaving the viewpoint from which the observers view the stimuli constant for the duration of the experimental block, independent of any observer head motion. In active viewing (middle schematic), the visual scene updates in response to head jitter, thus (slightly) changing the viewpoint from which the observers observe the stimuli. In lagged viewing (right schematic), the scene updates with a random 0–500 ms delay (denoted ‘L’ in the figure) beyond the inherent latency of the VR system. Note that the lagged updating does not preclude the trial events from occurring at their normal pace. (b) Head jitter contingent motion parallax improves performance. Percentage of trials in which observers’ paddle settings intercepted the target for each of the three viewing conditions and target contrast levels. Error bars correspond to +/− 1 SEM. A * corresponds to a significant paired-sample difference between the two viewing conditions at the two-tailed Bonferroni-corrected alpha level = 0.0167 for multiple comparisons. (c) Motion parallax reduces perceptual biases and errors. Reported motion direction as a function of presented direction for all 24 observers (40 trials each, targets presented at mid contrast, under the active viewing condition with task feedback) plotted for comparison with Fig. 1c.