Toward a minimally invasive brain-computer interface using a single subdural channel: A visual speller study

► Visual motion stimuli evoke cortical high gamma ECoG response. ► ECoG high gamma feature elevates BCI performance of visual speller. ► Spatial consistency is found between ECoG and fMRI response to visual motion. ► Location of subdural BCI electrodes can be determined by fMRI before surgery. ► Feasibility of minimally invasive BCI with single subdural electrode is demonstrated.