Figure 3. The fraction of quiescence and overall motion detected using the posture-based method.

(adapted from [15]). (A) Top: a schematic representation of the body of C. elegans. The midline of the worm was divided into 20 equi-length intervals (black/grey dashes) and the local angles at position i along the body, α_i, was defined as the angle formed between the intervals s_i−1 and s_i+1. Bottom: the temporal dynamics of eight angles during early L4leth. Quiescence at the localized position along the body was detected when α_i was constant or slowly relaxed at a sub-threshold rate (grey arrows). (B) Mean fraction of local quiescence at four anterior positions, one mid-body position and one posterior position. Quiescence is the lowest when tracking the most anterior position. (C) The QF of a single wild-type animal, determined based on the absence of motion of individual body-bends as detailed in [15]. (D) Top: the sum of the absolute rates of change of 18 angles, α₁…α₁₈, defined as in (A), corresponding to the overall motion of the animal. Bottom: the mean QF of wild-type animals. In panels (B) and (D) traces from different animals were aligned at the onset of lethargus quiescence, identified manually based on the posture data, as the start of a 30-minute period in which the QF increased at least 0.3. Shaded areas depict ± s.e.m., N=37 wild-type animals.