Figure 5.

Surround direction tuning: example cells. A, Stimuli used to measure surround direction tuning. The center receptive field contained a dot patch moving in the preferred direction and speed of the neuron. The surround receptive field was stimulated with an annular dot patch (outer diameter, 30°) that varied in direction. Both patches were high contrast and high coherence. B, C, Direction tuning of the center (blue) and surround (red) for two MT neurons. For the surround direction tuning curves (red), the center was always stimulated with dots moving in the preferred direction of the neuron. Thus, the responses when the surround moved in different directions should be compared with the blued dashed circle indicating the response to the center only at the preferred direction. The dotted lines indicate SEs.