Figure 1
From: Performance assessment in brain-computer interface-based augmentative and alternative communication
Architecture of a BCI-based AAC system that is comprised of two modules: (1) a BCI Control Module that translates brain signals into logical control outputs and (2) a Selection Enhancement Module that translates logical control to semantic control. Performance of BCI-based AAC systems can be measured at three levels (labeled Level 1, Level 2, Level 3) within this architecture; each level of measurement is currently assessed by a variety of often incommensurable performance metrics.