Figure 9.

Sources of stimulus-dependent modulation. A, Differences in either spatial or temporal stimulus statistics (stats.) could potentially modulate spatial and temporal response properties in V1. The four possible relationships between stimulus statistics and response modulation are indicated by arrows 1-4. Solid arrows indicate observed relationships. B, We assessed these potential relationships by comparing predictions of hybrid STRFs estimated using natural vision movies, grating sequences, and natural image sequences (n = 21 neurons). Labels marking each comparison indicate the relevant relationship in A. Solid lines indicate significant improvements in prediction accuracy (p < 0.05). These comparisons indicate that natural temporal stimulus statistics modulate both spatial and temporal response properties. Natural spatial statistics modulate spatial response properties, but they do not influence temporal response properties (dashed line). For details, see Results.