Figure 4

Effects of a visuo-auditory stimulus on the visual responses obtained from 49 single units recorded in V1 during a visuo-auditory saccadic task performed at three contrast levels (15%, upper row, 55%, middle row and 88%, lower row). The right panels represent the averaged normalized responses of the cells population during the V-only (blue) or visuo-auditory (red) conditions. The other panels show the distribution of the relative difference in the response rates (left) or latencies (middle) of the cells when the V-only and VA conditions are compared for each individual cell. A value of "0" means no difference, while negative values represent a decrease in the VA compared to V-only condition. At high and mid-contrasts no effects are observed concerning the response rate, while we observed a shift of the distribution of latencies toward negative values, indicating a shortening of the visual latency during the bimodal condition. The numbers of cells showing a reduction in latency are indicated in the brackets.