Figure 3.

Influence of stimulus size on retinal spike efficacy. A, B, Plots showing the relationship between stimulus size and the efficacy of retinogeniculate communication (black traces), where efficacy is the percentage of retinal spikes that evoked an LGN spike, for two representative pairs of RGCs and LGN neurons. For both cell pairs, efficacy peaks rapidly and then decreases as stimuli extended into the extraclassical receptive field. For reference, the area summation response functions of the LGN neurons are represented as gray traces. C, Scatterplot showing the relationship between efficacy values calculated when cells were excited with an optimal size stimulus and a large stimulus extending into the extraclassical surround. On average, efficacy decreased with large stimuli. D, ISI efficacy functions for optimal and large stimulus responses. For each ISI, retinal spikes are less effective in evoking an LGN response when evoked by a large stimulus compared with an optimal size stimulus.