Driving as night falls: the contribution of retinal flow and visual direction to the control of steering.

We have the ability to locomote at high speeds, and we usually negotiate bends safely, even when visual information is degraded, for example, when driving at night. There are three sources of visual information that could support successful steering. An observer fixating a steering target that is eccentric to the current heading must rotate their gaze. The gaze rotation may be detected by using head and eye movement signals (extra-retinal direction: ERD) or their retinal counterpart, visual direction (VD). The gaze rotation also transforms the global retinal flow (RF) field, which may enable direct steering judgments. In this study, we manipulate VD and RF to determine their contribution toward steering a curved path in the presence of ERD. The results suggest a model that uses a weighted combination of all three information sources, but results also suggest that this weighting may change in reduced visibility, such as in low-light conditions.