Fig. 5.

Simulated responses to motion stimuli with sound-source trajectories of constant angular velocity along an azimuthal slice through an inseparable (A) (PD = 23,788; df = 20,493; p < 0.01), and a separable (B) (PD = 7,534; df = 20,493;p > 0.01) space-time receptive field. Theblack and red lines represent opposing directions (left-to-right vsright-to-left). The solid lines represent slower speeds, and the dotted lines represent higher speeds. The predicted instantaneous spike rates to theblack and red sound trajectories are shown in the right panels. The space-time inseparable receptive field (A) produces greater peak responses to the black compared with the redtrajectory. The separable receptive field (B) responds nearly identically to the two opposing trajectories. The receptive fields of both neurons A and B were measured with a Poisson rate λ of 20 sound events per second. The receptive field in A is the same unit also shown unwrapped in Figure 3.