Fig. 5.

The transformation of a neuron's mixture of Gaussians models by segmental gain modulation. A: mixture of Gaussians model derived from local motion responses in the 9 stimulus segments. B: corresponding fit of the local motion model to neuronal responses to the 36 planar stimuli (format as in Fig. 2). C: corresponding fit for the local motion model (red) to the 16 optic flow patterns showing a poor model fit to the neuronal responses (blue). D: mixture of Gaussians model after segmental gain modulation. E: segmental gain changes that were implemented by the model to modulate the weight of the mixture of Gaussians model in each of the 9 segments (increases, green; decreases, brown; full-scale ± 10×). F: fit of the segment gain modulated model to the 16 optic flow patterns shows a substantial improvement for all optic flow stimuli compared with that of the unmodulated local motion model shown in C.