High-density ECoG speech decoding
Recording cortical surface potentials from subdural grids with small, closely spaced contacts, millimeter to sub-centimeter pitch, hundreds to more than a thousand channels, placed over speech motor cortex, capturing high spatial and temporal resolution without penetrating the brain.
The Chang lab's speech-synthesis and avatar systems use custom high-density grids over ventral sensorimotor cortex. ECoG trades the single-neuron resolution of intracortical arrays for broader cortical coverage, freedom from penetrating-electrode failure modes, and stable population-level signals suited to multi-year use.
Research high-density grids often far exceed the channel counts and density of FDA-cleared clinical ECoG; contrast with intracortical Utah-array speech systems that extract finer signals from a much smaller cortical patch.