Discriminating External and Internal Causes for Heading Changes in Freely Flying Drosophila

• DOI: 10.1371/journal.pcbi.1002891
• Publication Date: 2013-03-01T14:16:55Z
• Authors: Andrea Censi; Andrew D. Straw; Rosalyn W. Sayaman; Richard M. Murray; Michael H. Dickinson
• Keywords: Unobservable; Stimulus (psychology); Sensory cue

As animals move through the world in search of resources, they change course reaction to both external sensory cues and internally-generated programs. Elucidating functional logic complex algorithms is challenging because observable actions animal cannot be unambiguously assigned externally- or internally-triggered events. We present a technique that addresses this challenge by assessing quantitatively contribution stimuli internal processes. apply analysis rapid turns ("saccades") freely flying Drosophila melanogaster. show single scalar feature computed from visual stimulus experienced sufficient explain majority (93%) turning decisions. automatically estimate value trajectory, without any assumption regarding processing. A posteriori, we estimated field consistent with previous results measured other experimental conditions. The remaining decisions, not explained input, may attributed combination deterministic processes based on unobservable states purely stochastic behavior. distinguish these contributions using observations alone, but are able provide quantitative bound their relative importance respect stimulus-triggered Our suggest comparatively few saccades free-flying conditions result an intrinsic spontaneous process, contrary suggestions. discuss how could generalized for use systems employed as tool classifying effects into sensory, decision, motor categories when used analyze data genetic behavioral screens.