Fig. 4. Experiment 2. Effect of temporal changes of pattern velocity on flight speed. (A) Mean flight speeds when the pattern is stationary in the first phase and moving in the second phase. (B) Mean flight speeds when the pattern is moving in the first phase and stationary in the second. In each case, the open squares and filled circles indicate mean flight speeds during the stationary and moving phases, respectively. The solid line represents a regression model of the data; the equation for this line is shown on each graph. The error bars through the centre of each point indicate the standard error of the mean. The error bars to the left of each data point indicate the standard deviation for the stationary period (open squares); the bars to the right of each data point indicate the standard deviation for the moving period (filled circles). Other details are as in Fig. 3.