Bayesian Integration and Non-Linear Feedback Control in a Full-Body Motor Task
A) Observed center of pressure for a typical subject and trial along with the center of pressure predicted by each of the three ideal observer models. Note that the linear-quadratic-regulator and the bang-bang controllers produce qualitatively very different estimates. Note also that the non-linear LQR model has some ability to interpolate between the two. B) Cross-validated fraction of variance explained for each model for both the low and high-gain experiments (two-fold cross validation). In the low-gain condition the ideal optimal observer models explain a significantly larger fraction of variance than the PID controller (p<0.05, one-sided paired t-test), and the non-linear LQR explains a significantly larger fraction of variance than all others (p<0.001, one-sided paired t-test). Error bars denote SEM across subjects.