Background

Edward Chang is Chair of Neurological Surgery at UCSF and a leading researcher in speech neuroprosthetics. His laboratory has pioneered the use of electrocorticography (ECoG) electrodes to decode intended speech from brain signals in paralyzed patients, establishing new methodological foundations for speech restoration BCIs.

Speech Neuroprosthetics Innovation

Chang developed recording and decoding techniques using ECoG electrode grids positioned on the brain’s surface to identify neurons encoding speech intentions. Rather than requesting patients to imagine moving limbs, his approach directly targets speech motor representations in the motor cortex and adjacent language areas.

Real-time Speech Decoding

His laboratory demonstrated real-time decoding of intended speech from paralyzed patients, with results approaching conversational-speed communication rates. The approach translates decoded neural signals into synthesized speech or text output, enabling communication to family members and caregivers.

Clinical Translation

Chang’s work establishes ECoG as a viable recording modality for clinical BCIs, with advantages over penetrating intracortical electrodes including simpler surgery and potentially improved chronic safety. His clinical investigations at UCSF bridge neurosurgical expertise with speech neuroscience.

Impact on the Field

By focusing on speech rather than gross motor control, Chang expanded the scope of BCI applications and addressed a distinct aspect of paralyzed patients’ most profound communication limitations. His methodological innovations inform competing commercial companies developing speech BCIs.