Improving the Efficacy of ERP-Based BCIs Using Different Modalities of Covert Visuospatial Attention and a Genetic Algorithm-Based Classifier
Figure 2
Scheme of a “target” trial: a) initial situation of a session: the fixation point (white cross), the cursor (the circle initially placed at the center, colored in blue), and the four arrows were displayed on the monitor; b) one arrow changed color for 150 ms; c) if the classifier recognized the “target” ERP pattern, then the cursor was moved one step towards the spatial position of the arrow that had changed color; d) next trial (ITI 2.5 sec): an arrow in a different spatial position changed color. Note that the target was the X placed close to one of the arrows, which was colored in red.