10.1371/journal.pcbi.1002890.g014 Eduardo J. Izquierdo Eduardo J. Izquierdo Randall D. Beer Randall D. Beer Model worm. Public Library of Science 2013 Computational biology neuroscience computer science Evolutionary biology 2013-02-07 00:47:09 Figure https://plos.figshare.com/articles/figure/_Model_worm_/162829 <p><b>A</b>, Idealized body. The model worm was represented as a point (<i>x</i>, <i>y</i>) located at the center of the border between idealized head and neck regions of the model. The quantity <i>μ</i> is the angle between the instantaneous velocity vector <i>v</i> and the positive <i>x</i> axis. The dorsal (gray) and ventral (black) motor neuron pairs receive out of phase oscillatory input from the body. <b>B</b>, Changes in orientation. Between time steps <i>i</i>−1 and <i>i</i>, the orientation of the velocity vector changes by the turning angle <i>φ</i>. The gray arc is the model worm's path. <b>C</b>, Terminology. Orientation vectors used in the analysis of sinusoidal locomotion. Undulations occur in the <i>x–y</i> plane. The <i>white circles</i> represent the start and end of one locomotion cycle. Solid section of the trajectory represents ventral head sweeps. Dashed section of the trajectory represents dorsal head sweeps.</p>