Figure 2.

Movement generation in a network model of M1

(A) Schematics of our M1 model of motor pattern generation. The dynamics of an excitation-inhibition network (Hennequin et al., 2014) unfold from movement-specific initial conditions, resulting in firing rate trajectories (left; five neurons shown), which are linearly read out into joint torques (middle), thereby producing hand movements (right). The model is calibrated for the production of eight straight center-out reaches (20 cm length); firing rates and torques are shown only for the movement colored in black. To help visualize initial conditions, firing rates are artificially clamped for the first 100 ms. See also Figure S1.

(B) Network activity and corresponding hand trajectories as in (A), for three different preparation lengths, under the naive feedforward strategy whereby a static input step (green) moves the fixed point of the dynamics to the desired initial condition.