Current steering

Distributing a stimulus across two or more neighbouring electrodes with fractionally weighted currents so that the effective centre of activation lies between the physical contacts, or so that the recruited region is enlarged or reshaped. By interpolating between electrodes, current steering can create intermediate projected fields that no single electrode reaches, effectively increasing spatial resolution beyond the fixed electrode pitch.

The idea is borrowed from cochlear implants and spinal cord stimulation, where virtual channels between contacts expand the achievable set of percepts. In cortical ICMS it offers a route to smoother, denser sensory maps and to steering a percept along the skin, at the cost of a much larger, harder-to-search parameter space and of overlapping fields that interact non-linearly.