Sensory systems are the interface between an animal and its environment. Therefore, it is essential for the survival of a species that its sensory neurons are optimized for encoding all behaviorally relevant information contained in a stimulus. However, the characteristics of the sensory input perceived by an animal change over time depending on both the external world and the behavioral state of the animal. In the visual system of vertebrates and invertebrates the question of how sensory

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... s adapt to different stimulus statistics has been investigated to a great extent, including information theoretical work on synthetic as well as natural stimuli. However, little is known about the influence of the behavioral state on sensory processing, because most work on sensory processing has been restricted to immobilized and/or anesthetized animal preparations. Since the behavior of an animal has a strong influence on the perceived stimulus, it might be of evolutionary advantage to adapt the response properties of sensory neurons to the behavioral state. Recent work, in vertebrates as well as insects, demonstrated that the behavioral state of an animal indeed has an influence on sensory processing. Motion vision in flies is especially suitable for studying how the motor-activity of an animal can change sensory processing. The dynamic range of visual input in flies changes dramatically from the values at rest, through walking, to flying. Furthermore, lobula plate tangential cells (LPTCs), the neurons coding for self-motion based on optic-flow, are well described. In this work I investigated whether and how visual response properties of LPTCs depend on the behavioral state. I focused on the response