Fig. 8.

Responses to annular stimuli reveal surround facilitation to naturalistic stimuli. A: saturated color traces show responses of an example cell to a circular patch of noise (red) or naturalistic (blue) texture. Desaturated color traces show responses to an annular patch. The x-axis indicates the outer diameter of circular patches and inner diameter of annular patches. Inset images show example circular (top) and annular (bottom) stimuli with matched outer and inner diameters, respectively. The example annular stimulus at bottom right represents the size of the annular minimum response field (AMRF) for the neuron, because naturalistic stimuli windowed within an annulus with this inner diameter drove a response above the spontaneous rate. Error bars represent ±SE across samples and repetitions. Gray horizontal line represents mean spontaneous activity. Dashed vertical line represents the classical receptive field size estimate from gratings. B: responses from a different example cell exhibiting no surround suppression and a strong preference for naturalistic over noise stimuli presented within an annulus for all sizes that drive a response. Inset image shows an example of the texture family used to stimulate the neuron. Arrow indicates diameter of the AMRF for this neuron; ips, impulses/s.