Objects in motion appear shifted in space. For global motion stimuli we can ask whether the shift depends on the local or global motion. We constructed arrays of randomly oriented Gaussian enveloped drifting sine gratings (dynamic Gabors) whose speed was set such that the normal component of motion was consistent with a single global velocity. The array appears shifted in space in the direction of the global motion. The size of the shift is the same as for arrays of uniformly oriented dynamic Gabors that are moving in the same direction at the same global speed. Arrays made up of vertically oriented gratings whose speeds were set to the horizontal component of the random array elements were shifted less far. This shows that motion-induced position shifts of coherently moving surface patches are generated after the completion of the global motion computation.

*SE*= 0.70) and for the random condition it was 7.39 arcmin (

*SE*= 0.70),

*p*= 0.22. The magnitude of the shift for vertically aligned gratings is close to that reported by De Valois and De Valois (1991) for individual Gabors at the minimum eccentricity used here (4 degrees; approximately 8 arcmin, see Figure 2 of De Valois & De Valois, 1991).

*g*cos(

*θ*), where

*g*is the global motion speed, and

*θ*is the orientation between the direction normal to the Gabor and the global motion direction. The horizontal component is

*g*cos

^{2}(

*θ*) (see Figure 3). All other parameters were as in Experiment 1.

*SE*= 0.2) to 8.05 arcmin (

*SE*= 0.29) at 90 degrees. While these data are well fitted by a straight line (black line, adjusted

*R*-squared = 0.981) it is also reasonably well fit by a sine-squared function (dotted line, adjusted

*R*-squared = 0.908). However, if we assume a square root law between position shift and the horizontal speed component we get a closer fit to the spatial shift data (dashed line, adjusted

*R*-squared = 0.987). Thus the data suggest that the horizontal spatial shift for oriented Gabors is consistent with a shift in the horizontal direction, which is proportional to the square root of the velocity, or equivalently the horizontal component of a shift in the direction of motion, which is proportional to the square root of velocity.

*g*cos

^{2}(

*θ*), where

*g*is the global drift speed used in Experiment 1, and

*θ*is chosen at random from the 18 orientations used in the random condition. All other methods are as in Experiment 1.

*SE*): parallel condition = 8.05 (

*SE*= 0.29), random condition = 8.39 (

*SE*= 1.08)). The shift in Experiment 3 = 5.64 (

*SE*= 0.25) is present but is considerably smaller. So while there is an identical distribution of horizontal components in this experiment and the random condition of Experiment 1, we do not see a comparable shift.