Properties of oscillations. Oscillations are predictive of movement. (a,b) Distribution of strongest oscillation frequencies (a) and scores (b) across the in vitro dataset (blue). Also shown are the corresponding distributions for the shuffled controls (red). The mean of the oscillation scores is 6.0, while for the shuffled controls it is 3.5 (P<0.001). (c) Phase relationships between shape mode oscillations. Frequency distributions of phase relationships are shown for pairs that showed consistent relationships for the five significant modes in the in vitro (no gradient) dataset. The lack of consistent phase between R (reflective) and S (symmetric) modes is not surprising, due to their fundamentally different symmetry properties. If, for instance, R1 and S1 were consistently in phase, it would mean that growth cones bending left were consistently fatter (or thinner) than growth cones bending right. (d,e) Average step length is correlated with mode S1 oscillation strength (see Methods) (d) and mode R1 oscillation frequency (e). (f) Strengths and frequencies of all significant modes together are predictive of average step length. See Tables 2, 3 and 4.