The FACTS model of speech motor control: Fusing state estimation and task-based control
Fig 6
FACTS model simulations of mechanical and auditory perturbations.
Times when the perturbations are applied are shown in gray. (A) shows the response of the model to fixing the jaw in place (simulating a downward force applied to the jaw) midway through the closure for second consonant in [aba] (left) and [ada] (right). Unperturbed trajectories are shown in black and perturbed trajectories in red. The upper and lower lips move more to compensate for the jaw perturbation only when the perturbation occurs on [b], mirroring the task-specific response seen in human speakers. (B) shows the response of the FACTS model to a +100 Hz auditory perturbation of F1 while producing [ǝ]. The produced F1 is shown in black and the perceived F1 is shown in blue. Note that the perceived F1 is corrupted by noise. The model responds to the perturbation by lowering F1 despite the lack of an explicit auditory target. The partial compensation to the perturbation produced by the model matches that observed in human speech.