Predictability and hierarchy in Drosophila behavior
authors: Gordon J. Berman, William Bialek, Joshua W. Shaevitz
doi: 10.1073/pnas.1607601113
CITATION
Berman, G. J., Bialek, W., & Shaevitz, J. W. (2016). Predictability and hierarchy in Drosophila behavior. Proceedings of the National Academy of Sciences, 113(42), 11943–11948. https://doi.org/10.1073/pnas.1607601113
ABSTRACT
Significance How an animal chooses to order its activities—moving, grooming, resting, and so on—is essential to its ability to survive, adapt, and reproduce. Here we investigate the temporal pattern of behaviors performed by fruit flies, finding that their movements are organized in a hierarchical manner that exhibits long time scales. This organization is likely advantageous for adaptability and ease of neural representation and provides hints as to the form of the fly’s internal representations of behavioral programs. , Even the simplest of animals exhibit behavioral sequences with complex temporal dynamics. Prominent among the proposed organizing principles for these dynamics has been the idea of a hierarchy, wherein the movements an animal makes can be understood as a set of nested subclusters. Although this type of organization holds potential advantages in terms of motion control and neural circuitry, measurements demonstrating this for an animal’s entire behavioral repertoire have been limited in scope and temporal complexity. Here, we use a recently developed unsupervised technique to discover and track the occurrence of all stereotyped behaviors performed by fruit flies moving in a shallow arena. Calculating the optimally predictive representation of the fly’s future behaviors, we show that fly behavior exhibits multiple time scales and is organized into a hierarchical structure that is indicative of its underlying behavioral programs and its changing internal states.
fleeting notes
recorded 59 male flies at 100hz over the course of one hour in an individual arena
the goal was to understand behavioral organization and hierarchy
created a 2D map of fly behavior using an unsupervised approach
takes pixel values and decomposes into low dimensional basis set to describe fly posture
behavioral transitions are most often between similar actions
the transitions between behaviors exhibit multiple time scales and possess memory that persists for tens of minutes
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what does this mean for behaviors to have memories?