There are limitations. The answerer isn’t just thinking about the word ‘yes,' the way most of us would imagine mind-to-mind communication, but staring at a light that has been assigned to mean ‘yes.’ And right now, the asker can’t respond brain-to-brain, though that’s something the team is working on. The team is also experimenting with ways to move beyond binary yes/no type answers. Prat said they could use different kinds of stimulations to allow more answer options. They could use quadrants of space or different visual or auditory cues and patterns.