< Back to Article

Dimensionality and Dynamics in the Behavior of C. elegans

Figure 3

Motions along the first two eigenworms.

(A) The joint probability density of the first two amplitudes, ρ(a1, a2), with units such that . The ring structure suggests that these modes form an oscillator with approximately fixed amplitude and varying phase φ = tan-1(-a2/a1). (B) Images of worms with different values of φ show that variation in phase corresponds to propagating a wave of bending along the worm’s body. (C) Dynamics of the phase φ(t) shows long periods of linear growth, corresponding to a steady rotation in the {a1, a2} plane, with occasional, abrupt reversals. (D) The joint density ρ(|ν|,|ω|). The phase velocity ω = /dt in shape space predicts worm’s crawling speed.

Figure 3