Item

Abstract

When approaching a landing site flies (Musca domestica) extend their legs in order to prevent crash-landing. Pattern expansion in front of a tethered fly can mimic an approach towards a landing site. Under these conditions landing is a rather stereotyped motor pattern. Only the latency of the onset of the landing response varies with the stimulus strength. Quantitative studies of the stimulus-latency relationship led to the formulation of a simple model which describes the way movement information at the fly's retina is processed in order to trigger landing. We propose that the output of local directionally selective movement detectors are spatially pooled and subsequently integrated in time. Whenever the level of this integrated signal reaches a fixed threshold landing is released.