Attempted vs. imagined speech

Two experimental instructions with very different neural signatures. Attempted speech asks the user to actually try to speak, to issue motor commands and move, or attempt to move, the articulators, which robustly engages speech motor cortex even when paralysis prevents any sound. Imagined or covert speech asks the user to say the word silently in the mind with no motor effort.

Across intracortical and ECoG studies, attempted speech produces markedly stronger, more consistent and more decodable motor-cortex signals; consequently almost every high-performance clinical speech BCI instructs attempted, not imagined, speech, and reports that participants can sustain attempted speech even years after losing the ability to vocalize.