Independent brain computer interface control using visual spatial attention-dependent modulations of parieto-occipital alpha

Parieto-occipital alpha band (8-14Hz) EEG activity was examined during a spatial attention-based brain computer interface paradigm for its potential use as a feature for left/right spatial attention classification. In this paradigm 64-channel EEG data were recorded from subjects who covertly attended to a sequence of letters superimposed on a flicker stimulus in one visual field while ignoring a similar stimulus in the opposite visual field. Increases in alpha band activity were observed over parieto-occipital cortex contralateral to the location of the ignored stimulus, consistent with previous reports, and the subsequent use of alpha band power over bilateral parieto-occipital sites as a feature yielded an average classification accuracy of 73% across 10 subjects, with highest 87% The highest achievable bit rate from these data is 7.5 bits/minute.