The location effect of a black bar on the fixation performance of WTB flies.

(A) The MED had a significant location dependence (p = 1.4509×10⁻⁹). The best location for black bar fixation was 10° below the flies. (B) The fixation performance at 2 locations (−10°; 30°) was selected to show more details of the dwelling time in the whole panorama. Note the sharp peak in the dwelling time in the central quadrant (−45∼+45° area around the bar in the panorama) at the location θ = −10°; the distribution of dwelling time was quite even at the location θ = 30°. (C) Obvious location dependence in the rDT_abs between the central quadrant and the rest area (p = 1.1145×10⁻⁸). (D) There was no obvious location dependence in the rDFS between the central quadrant and the rest area (p = 0.7273). These differences were quite small. The data in (A&B) are given as the mean±SEM; the data in (C&D) are shown by box plot; the red crosses represent outliers; the p values were calculated by the Kruskal-Wallis test; the y-axes of certain charts are truncated for compactness.