Static and Dynamic Visual Fields in Human Space Perception

Human space perception is discussed in the context of the environmental geometry around a moving eye. It is shown that the interpretive scaling of visual angle is a key factor in size, distance, and motion estimation. The analysis of the velocity-vector pattern indicates that, contrary to the motion-parallax cue to distance suggested by Helmholtz, the pattern would not reveal distance, particularly on a curved trajectory. It is pointed out that the angular acceleration of an environmental point, seen by a moving eye, increases as the square of velocity. The consequences of this interesting relationship for the perception of speed are indicated. The pattern of the angular-acceleration field does not appear to resemble any familiar pattern of visual experience. Evidence is therefore provided that acceleration is not directly sensed.