Department of Biology, Duke University, Durham, United States.
Department of Neurobiology, Duke University, Durham, United States.
Elife. 2019 Jan 8;8:e41235. doi: 10.7554/eLife.41235.
Most behaviors such as making tea are not stereotypical but have an obvious structure. However, analytical methods to objectively extract structure from non-stereotyped behaviors are immature. In this study, we analyze the locomotion of fruit flies and show that this non-stereotyped behavior is well-described by a Hierarchical Hidden Markov Model (HHMM). HHMM shows that a fly's locomotion can be decomposed into a few locomotor features, and odors modulate locomotion by altering the time a fly spends performing different locomotor features. Importantly, although all flies in our dataset use the same set of locomotor features, individual flies vary considerably in how often they employ a given locomotor feature, and how this usage is modulated by odor. This variation is so large that the behavior of individual flies is best understood as being grouped into at least three to five distinct clusters, rather than variations around an average fly.
大多数行为，如泡茶，不是刻板的，而是有明显的结构。然而，客观地从非刻板行为中提取结构的分析方法还不成熟。在这项研究中，我们分析了果蝇的运动，并表明这种非刻板行为可以很好地用层次隐马尔可夫模型（HHMM）来描述。HHMM 表明，苍蝇的运动可以分解为几个运动特征，气味通过改变苍蝇执行不同运动特征的时间来调节运动。重要的是，尽管我们数据集中的所有苍蝇都使用相同的运动特征集，但个体苍蝇在使用给定运动特征的频率以及气味如何调节这种使用方式方面差异很大。这种变化非常大，以至于个体苍蝇的行为最好理解为至少分为三到五个不同的聚类，而不是围绕平均苍蝇的变化。
