First results indicate that the fly learns faster to meet the stepping stones when the contrast between stones and background is strong then when it is weak. Experiments under partial visual deprivation show that particularly the lower and the frontal eye regions are important for the precision of placement. In contrast, the precision of leg placement is hardly affected when the complete lateral or rear eye regions are covered with black paint. Only the hind legs get worse under these conditions. Visual information influences the precision of placement also in an indirect manner, i.e. via the visibility of landmarks.
Attractive landmarks lead to an average increase of walking speed and, hence, also of step lengths.
The average probability to hit stepping stones by chance can vary because of this effect for a given gap size between the stepping stones. Orientation Behavior R. Straus, M. Mronz Normal flies choose objects to explore according to, among other factors, their size and distance. After an unsuccessful visit attempt, they avoid immediately choosing an unapproachable object again. Certain defects in the central complex lead to permanent changes in orientation behavior, while others lead to an immediate new orientation as soon as the target has been even only temporarily lost from sight. In contrast, defects in the noduli or the protocerebral bridge do not lead to measurable changes in course maintenance.