PROJECT SUMMARY Neurological injury that results in the loss of communication is devastating. This proposed pilot trial is designed to evaluate the feasibility of speech prosthetic technology in a small cohort of paralyzed patients. We will leverage a decade-long scientific investigation of the functional properties of human speech motor cortex, and recent demonstration of speech decoding in normally speaking patients implanted with electrodes (for epilepsy surgery planning). We propose an early feasibility study of a long-term direct neural interface for restoration of communication. We propose three critical innovations to achieve this goal: 1) a chronically implanted high- density 128 channel electrocorticography (ECoG) array which samples from the entire lateral motor cortex (including speech motor cortex), 2) application of state-of-the-art neural network decoding approaches, and 3) direct comparison of text and speech synthesis decoder approaches. Electrocorticography is a method of recording neural activity (local field potentials) from the brain surface using non-penetrating electrodes. We hypothesize that ECoG may have distinct advantages for clinical application over current alternatives (e.g. microelectrode or scalp EEG) given that we can achieve both high-density sampling and cover the entire speech motor cortex. We have previously demonstrated that this scale and coverage is necessary and sufficient to decode speech in intact individuals. ECoG has an increasing well documented safety and reliability profile for long-term implantation in human medical applications such epilepsy and brain computer interfaces. We have already de-risked regulatory hurdles with FDA IDE and local IRB approval for investigational use. The primary goals of the study are to enable communication via text and synthesized speech decoded from neural signals. The secondary goal is to demonstrate the robustness and stability of ECoG-based recordings in the chronic implantation setting. These aims will determine the feasibility of speech neuroprosthetic technology in target population of patients who are paralyzed.