A continuum of predictive control between motor and mental actions: language production as a test case

Research traditions have studied aspects of control from their respective perspectives, separating motor and cognitive actions. This becomes particularly evident in the field of language and speech motor control in which linguistic language production models leave sensorimotor aspects underspecified and speech production models largely ignore the linguistic processing that provides a speech motor goal in the first place. It would be surprising if the brain organized control of speaking in such a dichotomous way. Here, we review and discuss conceptual proposals and empirical evidence supporting a hierarchical control architecture that allows for an embedded control of both abstract language as well as concrete speech. We propose a control scheme that could explain inner speech, speech planning, speech production, and speech perception in a single model. We propose concrete study designs that may disprove our proposal. • A hierarchically organized control scheme explains both language and speech • Predictions and prediction errors occur along a concrete to abstract continuum • Observed anatomical and temporal gradients support such a continuum • Speech error biases and feedback perturbations should be studied within subjects