A novel paradigm for two-degree-of-freedom BCI control based on ERP in-duced by overt and covert visual attention

Objective.This study developed a novel brain-computer interface (BCI) paradigm based on event-related potentials (ERPs) to achieve simultaneous two-degree-of-freedom control through overt and covert visual selective attention.Approach.In this paradigm, three stimuli were arranged equidistantly around the cursor. Participants selected two stimuli as attention targets based on the relative position of the cursor and the intended movement destination, focusing overtly on one while covertly attending to the other. EEG data collected during offline experiments were used to train classifiers for overt and covert targets (CT), and the outputs of these classifiers were employed in online experiments to construct movement vectors for controlling the cursor in a 2D space.Main results.EEG analysis demonstrated that overt and CT elicited distinct ERP signals, with classification accuracies of 96.2% and 92.4%, respectively. The accuracy of simultaneously identifying both targets reached 91.0%. In online experiments, the success rate of moving the cursor to the target region was 92.6%, and 88.2% of cursor movements were in the desired direction. These results confirm the feasibility of achieving 2D control through ERP based selective attention and validate the effectiveness of the proposed paradigm.Significance.This study introduces a novel EEG-based approach for multi-degree-of-freedom control, expanding the capabilities of traditional ERP based BCIs, which have primarily been limited to single-degree-of-freedom applications.