Suppressive interactions between moving patterns: role of velocity.

Detection and use of motion in complex environments requires movement measurements to be combined. The role of velocity in the suppressive interaction between patterns that move in orthogonal directions was assessed. When dmax was measured, it was found that a range of medium to high speeds of vertical motion all had a suppressive effect upon detecting horizontal motion. When dmin was measured, only a range of low velocities caused a disruption of performance. Thus, whilst velocity is an important parameter in determining the size of the suppressive effect, it has nonparallel influences at the upper and lower end of the displacement range.