Invasive neurophysiology to elucidate the neural correlates of speech

Speech is so central to the human experience that impairments of communication through speech are among the most devastating consequences of neurological illness. Invasive recordings are a privileged technique to investigate the cortical activity that underlies the processing and production of speech. I will present the results of two recent projects. First, I will show the crucial role of oscillatory phase in the cortical processing of visual speech cues, and its impact on the perception of audiovisual speech. Then, turning to speech production, I will examine the neural correlates of inner, or covert, speech. This fascinating topic has gained importance as progress in neurotechnology now makes it possible to envision brain-computer interfaces based on chronic cortical implants to restore speech.